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Poster Gallery
Welcome to the 2021 National Coastal Conference poster gallery. The in person poster session is Wednesday September 29th from 5:30-7:30 pm CST. Virtual posters are indicated under the contact button. You can contact poster presenters before the session and through out the conference by using the contact button included in their information. Student posters are listed first followed by professional posters. Do not forget to vote for the best student poster by Wednesday September 29th at 11:59pm.
To view the posters, please click on the image above the title to see the full size image. Each title drops down to show the presenter bio, abstract, video presentation, and contact for questions. Click on the links to view all the information. The drop-down does not automatically minimize. To hide the additional information, click the title again.
SENSOR FOR INTRAWAVE BED LEVEL QUANTIFICATION ON A BEACH
Evan Mazur
Evan Mazur
University of Delaware
Evan is a PhD student at the University of Delaware working with Dr. Jack Puleo at the Center for Applied Coastal Research. Her research interests include analyzing urban flood pathways during extreme events and developing low-cost sensors for field measurements in coastal communities.
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Abstract
Abstract
Beaches along the coast are shaped by energy from waves, currents, and tides. Surges induced by short-term, high-impact storms exacerbate beach erosion owing to an increase in energy. The erosive processes transport sediment offshore reshaping the dune, berm and foreshore through inner surf and swash zone processes. Interestingly, the elevation changes vary over a wide range of time scales including intrawave. Understanding these short-term bed level dynamics during storms is important for assessing sediment transport processes and predicting damage to coastal communities. Additionally, intrawave bed level measurements can be used to validate numerical models that aim to predict beach, dune, and barrier morphodynamics during storms.
Affordable, accurate methods of continuous of high-frequency, high-resolution bed level measurements are integral in understanding the effect storms have on bed level progression and profile evolution. Several sensors exist but are either cost prohibitive or operate on visible light rendering them less useful in cloudy or nighttime conditions. This study develops a low-cost stand-alone sensor using an array of infrared (IR) devices to monitor bed level progression during a storm. The array has a vertical measuring range of ~0.5 m and is populated of 48 IR devices placed at a 0.01 m pitch. The array housing contains power and data logging components. Multiple housed arrays can be stacked vertically to increase measurement range when excessive erosion is anticipated. A series of lab tests will be completed to assess the array capability to identify the bed/water interface when changed incrementally in a controlled setting. Once validated, the sensor will be tested in the field during moderate conditions to confirm accurate bed level measurements from the array.
Affordable, accurate methods of continuous of high-frequency, high-resolution bed level measurements are integral in understanding the effect storms have on bed level progression and profile evolution. Several sensors exist but are either cost prohibitive or operate on visible light rendering them less useful in cloudy or nighttime conditions. This study develops a low-cost stand-alone sensor using an array of infrared (IR) devices to monitor bed level progression during a storm. The array has a vertical measuring range of ~0.5 m and is populated of 48 IR devices placed at a 0.01 m pitch. The array housing contains power and data logging components. Multiple housed arrays can be stacked vertically to increase measurement range when excessive erosion is anticipated. A series of lab tests will be completed to assess the array capability to identify the bed/water interface when changed incrementally in a controlled setting. Once validated, the sensor will be tested in the field during moderate conditions to confirm accurate bed level measurements from the array.
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Examining the influence of BUDM vs. offshore sediment on beaches for erosion mitigation practices in regards to sea turtle nesting patterns and hatching success: A case study from Palm Beach County, FL
Raquel Valdes
Raquel Valdes
Florida Atlantic University
Raquel is a graduate student in the Marine Science & Oceanography program at Florida Atlantic University working with Dr. Tiffany Roberts Briggs. Her research combines coastal morphology with marine biology in studying the possible impacts of nourished sediment on sea turtle nesting behavior and success.
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Abstract
Abstract
Florida contains some of the most essential sea turtle nesting sites in the world. Palm Beach County specifically accounts for over 25% of all hatchlings from the United States each year, while covering less than 7% of the total nesting area. However, many of these beaches have been designated as critically eroding, through sediment removal due to major storm events and human development on the coast. A warming climate can also magnify these conditions with stronger and more frequent storms. Therefore, a popular response in mitigating coastal erosion can be to nourish beaches using sediment from a borrow site, either from offshore, an adjacent inlet, or upland mines. These continued nourishment efforts can greatly diminish storm impact on coastal communities, maintain necessary coastal tourism locations, and preserve essential sea turtle nesting habitats. In recent years, however, the effect of this nourished sediment on sea turtle nesting patterns has come into question. The sand composition of nourished beaches can become altered over time, which can greatly impact nest site determination, final digging activity, egg chamber depth, sex ratios, ease of hatchling emergence, and the overall success of a nest. Therefore, it is the goal of this study to analyze the characteristics of borrowed sediment on nine sites in Jupiter, FL and compare these results to sites that are non-nourished. Specifically, sand color, grain size, carbonate content, and average temperature will be examined. The results of this study will aid in determining the sediment characteristics necessary for optimal sea turtle nesting behavior, as well as assessing the impacts of beach nourishment projects on nesting and hatching success.
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Event-driven Nearshore Sediment Transport and Morphology Change in Boca Raton, Florida
Michael Priddy
Michael Priddy
Florida Atlantic University
I earned my undergraduate degree in Geology from the University of Kentucky in 2015. My undergraduate research took me to central Alaska, where I camped with a small team of researchers in the far western end of Denali National Park. My research while there focused on studying the neotectonics and the glacial and tectonic geomorphology associated with the restraining bend in the Denali Fault.
After graduation I moved to the small mountain town of Coeur d’Alene, Idaho, in the western foothills of the Rocky Mountains and near the Canadian border. While there I was an adjunct geology instructor and the physics lab tech at North Idaho College for 5 years. My research while there centered around mapping Neoproterozoic diamictites as well as mapping the Mesoproterozoic stratigraphy of the Belt Supergroup of Idaho, Washington, Montana, and British Columbia.
Now at Florida Atlantic University as a Master’s of Science student, I work in the Coastal Studies Lab with Dr. Tiffany Briggs where I study coastal geology and geomorphology. My research focuses on event-driven nearshore sediment transport and resultant littoral morphology change.
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Abstract
Abstract
Tropical storms and mid-latitude cyclones are major drivers of coastal change and damage in coastal communities. Beaches act as a first line of defense against storms, as well as provide recreation, contribute to the economy, and serve as ecological habitat for coastal flora and fauna. Meteorological event-driven increases in wave energy result in higher amounts of sediment transport that cause rapid coastal zone morphology and threaten these beach functions. This study used streamer traps to evaluate cohesionless sediment dynamics in the surf zone and storm-induced morphology change. Traps were deployed for 60-second intervals to capture onshore, offshore, and alongshore sediment transport within the water column before and after two different storm events in Boca Raton, Florida. The volume and sedimentologic characteristics of sediment collected in the bottom bin (near the seabed) compared to the upper bins (within the water column) varied. Spatial and temporal differences in the quantity and granulometric characteristics of sediment in transport before and after a storm compared to normal conditions will be discussed. Results of this study should contribute to quantifying granulometric differences in sediment transport aimed at improving prediction capabilities for storm-driven beach morphology change.
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Spatiotemporal variability of dredge material placed at two inlet-adjacent beaches
Austin Scheinkman
Austin Scheinkman
Florida Atlantic University
Austin Scheinkman is a 2nd year Masters student at Florida Atlantic University studying Geosciences under Tiffany Roberts-Briggs. He did is Undergraduate at the University of Florida and studied Geology and how a Hurricane impacted a beach on the South Florida Coast under Peter Adams. His interest lie in management of the coast and inlets.
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Abstract
Abstract
Inlet management varies by locale due to factors such as infilling rates, dredge availability, and other economic or community influences. At some inlets, annual dredging of the channel removes large amounts of material and places it on downdrift beaches much like a typical nourishment project. Other locations dredge monthly continually pumping relatively smaller amounts of sediment at a given time onto downdrift beaches throughout the year. This study aims to evaluate two inlets in Palm Beach County using the two different management approaches. Monthly topographic surveys and cross-shore sediment sampling were conducted on the downdrift beaches at Boca and Jupiter Inlets, which are the southern- and northern-most inlets respectively. Boca Inlet dredges between 1,376-9,556 m³ of sediment throughout each month depending on the level of infilling of the inlet, totaling approximately 41,829 m³annually. Jupiter Inlet typically dredges annually with a yearly average of 35,307 m³ of sediment placed along the southern beach. During the first few months following placement in April and May 2021, subaerial scarping and initial profile equilibration morphology were measured in Jupiter. During the same period, the smaller amount of sediment pumped onto the Boca beach throughout each month did not have an obvious morphological signature, but rather showed subtle seaward progradation during the summer months. It’s important also to note that the initial results are from calmer summer months where longshore sediment transport is to the north with smaller morphologic change expected. However, both sites will continue to be studied through December to evaluate winter and storm-driven changes at the inlet-adjacent beaches as well.
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Simulating scenarios of ocean acidification impacts on sea oats
Evan Blanchard
Evan Blanchard
Florida Atlantic University
Evan Blanchard is an Environmental Science master’s student at Florida Atlantic University studying within the Coastal Studies Laboratory headed by Dr. Tiffany Briggs. He got his bachelors in Environmental Studies at Florida State University. Currently he also works part time for the Florida Department of Environmental Protection as an Environmental Resources Permitter, permitting projects involving wetland or surface waters impacts.
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Abstract
Abstract
Climate change has and will continue to acidify the world’s oceans with several studies showing adverse impacts on submerged aquatic vegetation. However, the effects an acidified ocean would have on terrestrial coastal vegetation from sea spray are less known. This study aimed to simulate various scenarios of future ocean acidification and test the subsequent health and growth of Uniola paniculate (common name: sea oats), which are a predominant coastal dune plant species. The sea oats were divided into four treatment groups and sprayed with artificially created seawater, each group exposed to a unique pH based on possible future scenarios ranging from 7.8-8.1pH. The thirteen-week experiment was conducted in the partially open air FAU greenhouse with as much exposure to natural conditions as possible. Preliminary results signify that sea oats well known resilience to extreme environmental conditions extends to pH as well. The sea oats being treated with the most acidic possible seawater seem to be in the same state of health as those treated with modern day pH. Results from these types of studies helps support current conservation efforts and promote confidence in current practices of planting and stabilization of sediment along coasts.
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SEDIMENTOLOGY AND BEACH SUBSTRATE TEMPERATURE INFLUENCES ON SEA TURTLE NESTING
Jyothirmayi Palaparthi
Jyothirmayi Palaparthi
Florida Atlantic University
I am Jyothirmayi Palaparthi, 2nd year PhD student at Florida Atlantic University working with Dr. Tiffany Roberts Briggs in the Coastal Studies Lab. This presentation is part of a larger study funded by the PBC Dept. of Environmental Resources Management. I had an Integrated M. Sc. Tech. degree in Applied Geology, IIT(ISM), India and M.S. degree in Geosciences, Florida Atlantic University. I was awarded Smt. Renuka Rajhans Memorial Gold Medal, Indian School of Mines (2014-2015 batch), INSPIRE Fellowship from Department of Science and Technology (DST), India (2010-2015), ASBPA Educational Award (2018), ASBPA Nicholas Kraus Coastal Scholar Award (2019)
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Abstract
Abstract
Florida beaches are important economic resources and home to thousands of nesting sea turtles every year. Beach-dune systems are periodically restored (beach nourishment) to mitigate erosion, enhance coastal habitat, protect from storms, and attract tourism. Different borrow sources with slight variability in their physical or mineralogical characteristics could affect substrate temperatures within placement areas, thereby potentially impacting sea turtle hatching and emergent success. On the other hand, certain state regulations on sediment properties for beach placement may restrict the degree of variability such that no impact on substrate temperatures may occur. Temperatures encountered during egg incubation will determine the gender of the sea turtle hatchlings but can also exceed a critical threshold resulting in embryonic mortality. Given the current trend of global warming, it will be critical to understand the role of sediment properties in shore protection projects on critical habitat function. This study evaluates the sedimentology and morphology at nine locations in Jupiter beach, FL with substrate temperature and the hatch and emergence success of loggerhead, leatherback, and green sea turtles during the 2019 nesting season. Grain size, sorting, and carbonate content at 45 cm depth below surface at three cross-shore locations were evaluated and compared to the temperature measured. Beaches with larger mean grain size (>0.67mm), poor sorting, and higher carbonate content (>75%) had lower measured temperatures (84°F-85°F). The reflectance shows negative correlation with the temperature. Upland and offshore borrow sediment sources have higher temperatures (>86 °F) and inlet dredged sediments have lower temperatures (84°F-85°F). At most locations, temperature had a positive correlation with the beach width. Loggerhead Hatch Success (HS) and Emergence Success (ES) had a high negative correlation (>0.90) with mean grain size, sorting and negative correlation (>0.85) with carbonate and leatherbacks have a no correlation (<0.5) with grain characteristics. On the other hand, HS and ES of greens had a positive correlation (>0.80) with mean grain size. The results of this study are aimed to support sediment resource management while promoting healthy beach ecosystems.
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*Virtual Participant
Variable Density Munitions Motion in the Swash Zone
Emily Chapman
Emily Chapman
Center for Applied Coastal Research, University of Delaware
Emily Chapman is a master’s student at the University of Delaware. She is majoring in Civil Engineering with a concentration in Coastal Engineering. She received her Bachelor’s degree in Civil Engineering at the University of Delaware. Her research interests include sediment transport and coastal structures.
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Abstract
Abstract
In recent years, unexploded ordnance (UXO; also referred to as munitions) from past military activities may become exposed along different coastlines after high energy storms. Variations in weather patterns induced by climate change have increased the frequency of these storms. Along with causing shoreline damage and flooding, storm driven surges potentially cause UXOs to resurface on coastlines. Despite the negative ecological and health impacts, the mobility (burial and exposure) of UXOs in the nearshore region is poorly understood. Furthermore, there is a knowledge gap in how the bulk density of munitions that may change over time affect mobility. A small-scale laboratory study was conducted to gain a better understanding of the processes driving variable density munition mobility. The experiments include surrogate munitions of 20 mm and 40 mm diameter. The 40 mm munitions were covered by Delrin of three different thicknesses to replicate decreases in munition bulk density due to long-standing biofouling, encrustation, and corrosion. The study was conducted in the Precision Wave Flume (33 m x 0.6 m x 0.77 m) at the Center for Applied Coastal Research at the University of Delaware using a dam-break mechanism. Each munition was tested under five consecutive wave bores for three repeated trials. Munitions were tested proud and 50% buried at two cross-shore locations. The burial, exposure, and migration of the surrogate munitions were quantified with high-precision sensors deployed across the flume. The changes in morphology were recorded with LIDAR systems. Electro-magnetic current meters and acoustic doppler profiling velocimeters quantified the cross-shore velocity and velocity profiles respectively. Ultrasonic distance meters and pressure sensor arrays were used to measure water depths. Preliminary results from the small-scale study will be presented. Data will be analyzed subsequently to narrow down the experimental parameters of a future near-prototype physical model study that will be conducted in a large wave flume (120 m x 5 m x 5 m) at the Institut National de la Recherche Scientifique, in Quebec, Canada.
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Using XBeach to Simulate Future Impacts of a Living Shoreline Project in Little Lagoon, Alabama.
Kelsey Carpenter
Kelsey Carpenter
University of South Alabama
Kelsey Carpenter is a graduate research assistant in the Department of Civil, Coastal, and Environmental engineering at the University of South Alabama under Dr. Bret Webb. Her research investigates the impacts of natural shoreline stabilization. Kelsey received her Bachelor of Science degree in Biology with a concentration in marine science from USA in 2018 and is currently studying to receive her Master of Science in Civil Engineering with an emphasis in coastal engineering.
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Abstract
Abstract
Little Lagoon is a shallow body of water located west of Gulf Shores, Alabama, and an erosion analysis has exhibited that some areas of the southwestern shoreline have been eroding since 1992. A living shoreline project is underway to mitigate this erosion by protecting habitat on the contiguous land of the Bon Secour National Wildlife Refuge by creating a staggered system of riprap sills with plantings and backfilling. This research will focus on comparing a “with project” and “without” project condition using XBeach in a 1-dimensional, transect-based mode extending into the future. This will be done in a probabilistic framework using Monte Carlo simulation techniques also including sea level rise effects. This poster presentation will describe the study area, project attributes, modeling and analysis framework, and the expected research outcomes. Once completed, this research will provide practitioners with a useful application for designing and implementing living shorelines.
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*No Recording Provided
Designing nature-based living shorelines in moderate energy systems: A case study on Pea Patch Island, Delaware River
Emma Ruggiero
Emma Ruggiero
University of Delaware
Emma Ruggiero is a Master’s student in the Department of Plant and Soil Sciences at the University of Delaware (UD). She holds a Bachelor of Science in Landscape Architecture with a minor in Biology from UD. Emma has worked on several design projects focused on coastal resilience and flood mitigation throughout Delaware as part of the Coastal Resilience Design Studio. Her research interests include nature-based infrastructure design, living shorelines for coastal protection, and regenerative landscape design. She recently completed a Master’s thesis exploring feasibility of a living shoreline installment on a remote site experiencing ship wake on the Delaware River.
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Abstract
Abstract
Living shorelines are designed coastal protection intended to enhance shoreline ecology and stability, buffer wave energy, and accrete shoreline sediments. Since living shorelines mimic, establish, or enhance natural features, their design may be as distinct as the natural coastal features they emulate. While the design of traditional hard-armor structures incorporates mainly hydrologic and physical parameters, living shorelines require consideration of additional physical and ecological parameters addressing living components of the design. Successful designs incorporate site-specific conditions and considerations of impact on natural shoreline hydrodynamics and local ecology. While hard-armor structures have clear design guidance, there is a lack of the same in living shoreline design. Guidance that addresses a set of conditions, accounting for site level features, is needed to further living shoreline use and implementation. Currently, there is little guidance for how living shorelines may be designed to protect or enhance areas with atypical conditions, including those impacted by recurring ship wake and higher wave energy, or sites with remote access. Innovative solutions that address wave energy with the most natural approach feasible are needed to combat shoreline erosion as sea levels rise, while contributing to ecological uplift. Conventional designs involving rock toe sill and coir log edging are well-suited to lower energy environments with stable substrate, but there is an opportunity for design innovation in areas with different physical and ecological parameters. This case study reviews the design process for a natural living shoreline implemented on a small estuarine island, known as Pea Patch Island, along a major shipping route (the Delaware River). This site is remote and experiences moderately high wake and wind-driven wave energy — characteristics that increase the complexity of living shoreline design and implementation. The installed design involves a groin and breakwater configuration of coir logs oriented to attenuate wake from the major shipping channel. Benefits of this natural design include increased permeability for reduced wave energy reflection, reduced costs, and increased ease of implementation.
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Impact of storm events on density stratification in the Pamlico and Albemarle Estuarine System
Brooke Rumbaugh
Brooke Rumbaugh
North Carolina State University
Brooke is currently a second year Master’s student working with Dr. Casey Dietrich at North Carolina State University. She is originally from Charleston, West Virginia. In 2019, she received her Bachelor’s degree in civil engineering at Marshall University. She decided to pursue coastal engineering for her Master’s as it allowed for her to apply what she had learned in her undergraduate degree for one of her favorite places. Her current research revolves around using a coastal ocean model. She hopes to continue modeling in her future career.
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Abstract
Abstract
“This project is focused on the Pamlico and Albemarle Sounds, located near the Outer Banks of North Carolina. Within these estuarine systems, exists both horizontal and vertical density stratification that allows for key circulation. When storm events occur, this stratification is disrupted, which can have disastrous influence on the ecosystem. The purpose of this research is to investigate how storm events affect the density stratification, e.g. how much and how quickly does the system mix during the storm, and then how long does it take for the system to recover?
To begin to answer these questions, we developed a three-dimensional model that included density circulation. The salinity and temperature fields were developed using a database of water quality data aggregated from the past 68 years. To overcome gaps in this database, both spatially and temporally, the data was interpolated using a geographic information system. This interpolation for the fields was completed using monthly averages based on all of the available data for that month. Then, using a density field for an average August, we applied forcings for Hurricane Irene (2011) and simulated how the storm affects circulation in the estuary system. To examine the time spans that the stratification was altered, comparisons were made between the averaged fields and those of the simulation results. Over the course of the simulation, various areas displayed key circulation movements. As the storm passed through the estuarine system, plumes of saline water came in through the ocean inlets and circulated within the Pamlico Sound and around Roanoke Island. In the Albemarle Sound, as the storm passed through, saline water was pushed further up into the sound. As the storm exited the area, the fresh water pushed further out into the Albemarle Sound. Circulation movements like these were seen at the surface as well as the bottom. These results indicate the shallow sounds and estuary system’s density stratification is highly influenced by storm winds. “
To begin to answer these questions, we developed a three-dimensional model that included density circulation. The salinity and temperature fields were developed using a database of water quality data aggregated from the past 68 years. To overcome gaps in this database, both spatially and temporally, the data was interpolated using a geographic information system. This interpolation for the fields was completed using monthly averages based on all of the available data for that month. Then, using a density field for an average August, we applied forcings for Hurricane Irene (2011) and simulated how the storm affects circulation in the estuary system. To examine the time spans that the stratification was altered, comparisons were made between the averaged fields and those of the simulation results. Over the course of the simulation, various areas displayed key circulation movements. As the storm passed through the estuarine system, plumes of saline water came in through the ocean inlets and circulated within the Pamlico Sound and around Roanoke Island. In the Albemarle Sound, as the storm passed through, saline water was pushed further up into the sound. As the storm exited the area, the fresh water pushed further out into the Albemarle Sound. Circulation movements like these were seen at the surface as well as the bottom. These results indicate the shallow sounds and estuary system’s density stratification is highly influenced by storm winds. “
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Observing the Change in Wave Energy Over Dauphin Island, AL During Hurricane Nate
Sean McQuagge
Sean McQuagge
University of South Alabama
Sean McQuagge is a graduate research assistant in the Department of Civil, Coastal, and Environmental Engineering at the University of South Alabama under Dr. Bret Webb. His research studies the morphodynamic response of barrier islands to hydrodynamic forcing caused by extreme events such as hurricanes and tropical storms. Sean received his Bachelor of Science in Mechanical Engineering from the University of Florida in 2017 and is studying to receive his Master of Science in Civil Engineering with an emphasis in coastal engineering.
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Abstract
Abstract
“Extreme events, such as hurricanes and tropical storms, can create significant change in the topography of a barrier island. Previous studies compared cross-shore elevations measured before and after storms, and some have measured nearshore wave forcing during storms. Research is lacking, however, in measuring the energy associated with island-overtopping waves during the storm and determining how these waves affect island morphodynamics.
Here we show time series of infragravity waves at various points across Dauphin Island, Alabama during Hurricane Nate (2017). Pressure sensors were placed along two cross-shore transects of Dauphin Island and used to estimate time-varying water levels and waves during the storm event. Data from these sensors were first filtered to separate waves from the storm tide hydrograph, and then filtered again to distinguish the gravity and infragravity wave components. A fast Fourier transform was applied in order to find the energy spectra at each sensor location, which allowed us to observe the change in cross-shore and alongshore wave energy over the duration of the hurricane. Here, infragravity wave components are compared to water levels during the storm in order to investigate the effects that barrier island overwash and inundation have on infragravity wave transmission.
To investigate the bed level change that occurred on Dauphin Island during the storm, computer model XBeach was used to simulate the effects of Hurricane Nate on the study site. Results of this simulation are shown here, with changing bed levels being compared to changing water levels and wave energy. The simulation results, as well as the data collected during Hurricane Nate, will help us better understand the behavior of wave energy during extreme events. This behavior will help outline the relationship between hydrodynamic forcing and barrier island morphodynamic response, as well as the selective dissipation of wave energy during overtopping events.”
Here we show time series of infragravity waves at various points across Dauphin Island, Alabama during Hurricane Nate (2017). Pressure sensors were placed along two cross-shore transects of Dauphin Island and used to estimate time-varying water levels and waves during the storm event. Data from these sensors were first filtered to separate waves from the storm tide hydrograph, and then filtered again to distinguish the gravity and infragravity wave components. A fast Fourier transform was applied in order to find the energy spectra at each sensor location, which allowed us to observe the change in cross-shore and alongshore wave energy over the duration of the hurricane. Here, infragravity wave components are compared to water levels during the storm in order to investigate the effects that barrier island overwash and inundation have on infragravity wave transmission.
To investigate the bed level change that occurred on Dauphin Island during the storm, computer model XBeach was used to simulate the effects of Hurricane Nate on the study site. Results of this simulation are shown here, with changing bed levels being compared to changing water levels and wave energy. The simulation results, as well as the data collected during Hurricane Nate, will help us better understand the behavior of wave energy during extreme events. This behavior will help outline the relationship between hydrodynamic forcing and barrier island morphodynamic response, as well as the selective dissipation of wave energy during overtopping events.”
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Adaptation Strategies to Mitigate Morphological Damage on Dauphin Island
Benji Delaney
Benji Delaney
University of South Alabama
I was born in Mobile, Alabama. I am a first generation student currently at the University of South Alabama pursuing my masters in Civil engineering. I grew up on Dauphin Island so being able to help protect the island is an amazing accomplishment.
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Abstract
Abstract
Dauphin Island is one of the barrier islands in the Alabama-Louisiana barrier island chain located 6.5 km off the coast of Mobile County, Alabama. Dauphin Island is home to about 1200 permanent residents along with seasonal vacationers.
In 2010, the catastrophic Deepwater Horizon Oil spill occurred. With the threat of oil contamination to the island and Mississippi Sound, a sand barrier was constructed on the Gulf side of Dauphin Island. Due to the urgency and budget, sediment was mined from private properties, with the consent of the owners, to construct the sand barrier. While the sand barrier prevented oil from overwashing the island and depositing landward and in Mississippi Sound, the borrow pits created small ponds along the north side near the west end beach significantly narrowing the island.
On October 7, 2017, Hurricane Nate made landfall as a Category 1 hurricane near Gulfport, Mississippi located 90 km west of Dauphin Island. At the storm’s peak intensity, sustained winds were around 41 m/s as the storm traveled across the Gulf of Mexico at a speed of 13 m/s. The storm surge in Gulfport peaked at 1.9 m and measured 1.0 m above MHHW at Dauphin Island. While Hurricane Nate produced relatively little damage to the infrastructure, Dauphin Island did experience overwashing and sediment deposition throughout the island. With the relative sea level trend rising at 4.13 mm/year, sea level rise (SLR) creates a concern that future storms, even those of similar intensity to Hurricane Nate, will cause overwash and/or breaches, particularly at the borrow pit site.
This presentation will demonstrate the morphological change due to Hurricane Nate and several SLR scenarios at the borrow pit site using XBeach. XBeach is a two-dimensional numerical model that simulates the impacts of beach erosion, overwash, inland flooding, and barrier island rollover and breaching. The calibrated XBeach model will be used to simulate five different adaptation strategies at the borrow pit site: (1) filling the borrow pits, (2) raising the dunes, (3) widening the beach, and (4 and 5) closing the breaks in the dunes with vegetation and gravel. The hydrodynamic forces from Hurricane Nate will then be altered with several different SLR scenarios. These values range from 0.53 m to 2.64 meters relative SLR projections for Dauphin Island by 2100. The results of the five adaptation strategies will be implemented into an adaptation pathway, a responsive planning tool intended to be used by planning committees and town officials.
In 2010, the catastrophic Deepwater Horizon Oil spill occurred. With the threat of oil contamination to the island and Mississippi Sound, a sand barrier was constructed on the Gulf side of Dauphin Island. Due to the urgency and budget, sediment was mined from private properties, with the consent of the owners, to construct the sand barrier. While the sand barrier prevented oil from overwashing the island and depositing landward and in Mississippi Sound, the borrow pits created small ponds along the north side near the west end beach significantly narrowing the island.
On October 7, 2017, Hurricane Nate made landfall as a Category 1 hurricane near Gulfport, Mississippi located 90 km west of Dauphin Island. At the storm’s peak intensity, sustained winds were around 41 m/s as the storm traveled across the Gulf of Mexico at a speed of 13 m/s. The storm surge in Gulfport peaked at 1.9 m and measured 1.0 m above MHHW at Dauphin Island. While Hurricane Nate produced relatively little damage to the infrastructure, Dauphin Island did experience overwashing and sediment deposition throughout the island. With the relative sea level trend rising at 4.13 mm/year, sea level rise (SLR) creates a concern that future storms, even those of similar intensity to Hurricane Nate, will cause overwash and/or breaches, particularly at the borrow pit site.
This presentation will demonstrate the morphological change due to Hurricane Nate and several SLR scenarios at the borrow pit site using XBeach. XBeach is a two-dimensional numerical model that simulates the impacts of beach erosion, overwash, inland flooding, and barrier island rollover and breaching. The calibrated XBeach model will be used to simulate five different adaptation strategies at the borrow pit site: (1) filling the borrow pits, (2) raising the dunes, (3) widening the beach, and (4 and 5) closing the breaks in the dunes with vegetation and gravel. The hydrodynamic forces from Hurricane Nate will then be altered with several different SLR scenarios. These values range from 0.53 m to 2.64 meters relative SLR projections for Dauphin Island by 2100. The results of the five adaptation strategies will be implemented into an adaptation pathway, a responsive planning tool intended to be used by planning committees and town officials.
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Analysis of Barrier Island morphological features along the Gulf and Atlantic Coasts
Sheppard Medlin
Sheppard Medlin
University of Georgia
Sheppard attended NC State University for his undergraduate program, where he obtained a Bachelor’s degree in Mechanical Engineering with a Minor in Physics. While there, he developed computational tools to visualize storm surge modeling results as a part of the Coastal and Computational Hydraulics Team. Now, Sheppard is continuing his education at the University of Georgia by working towards a Master’s degree in Environmental Engineering. He is currently studying the scales at which barrier islands become effective tools for protecting the mainland against coastal flooding.
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Abstract
Abstract
“Barrier islands are a common morphological feature – they are long, narrow islands that often form in series, approximately parallel to shore, in coastal environments around the world. They can be naturally occurring or manmade. As their name implies, barrier islands form a natural boundary between coastal estuaries and the open coastline. These barriers serve an important role during storms and hurricane events by attenuating the coastal flood hazard. Past numerical modelling studies which quantify the coastal flood attenuation by barrier islands observed that the level of attenuation provided by the barrier islands is dependent upon their scales and configuration. However, those studies only simulated a narrow range of existing islands with a few permutations (degraded or restored), mainly in the Gulf of Mexico. Hence, it is important to document and use the full naturally occurring range of barrier islands scales and configurations in numerical modelling efforts to provide guidance on the level of attenuation that can be expected by a given barrier Island.
In this study, we attempt to catalogue natural variability of the barrier Island scales and configurations through the compilation of a database of barrier island characteristics and the creation of a cross-validated Bayesian network. Data was gathered from over 20 barrier islands and 15 tidal inlets along the Gulf and Atlantic coasts from a variety of sources. 15 different morphological variables (mean barrier island width, maximum height, etc.) were chosen and data on these variables was compiled into one dataset. The dataset was then processed in Netica to create a Bayesian network. The network was cross-validated using the k-fold resampling technique. Network complexity was reduced by eliminating the variables with greatest prediction error and least influence on other variables. This reduces the number of simulations needed in our future work, while capturing the effects of the most important variables. The resulting network gives a better understanding of the morphological scale limitations on naturally occurring barrier island configurations along the Gulf and East Coasts of the United States. These insights will inform the next steps in the study where idealized barrier island landscapes will be modeled based on the variable range found in the data. This research will help to create guidelines on the connection between the barrier island scales & configurations and the level of flood mitigation that can be expected by them. Community leaders, coastal planners, and engineers, could use these guidelines to inform their coastal restoration projects given the communities’ location and needs.”
In this study, we attempt to catalogue natural variability of the barrier Island scales and configurations through the compilation of a database of barrier island characteristics and the creation of a cross-validated Bayesian network. Data was gathered from over 20 barrier islands and 15 tidal inlets along the Gulf and Atlantic coasts from a variety of sources. 15 different morphological variables (mean barrier island width, maximum height, etc.) were chosen and data on these variables was compiled into one dataset. The dataset was then processed in Netica to create a Bayesian network. The network was cross-validated using the k-fold resampling technique. Network complexity was reduced by eliminating the variables with greatest prediction error and least influence on other variables. This reduces the number of simulations needed in our future work, while capturing the effects of the most important variables. The resulting network gives a better understanding of the morphological scale limitations on naturally occurring barrier island configurations along the Gulf and East Coasts of the United States. These insights will inform the next steps in the study where idealized barrier island landscapes will be modeled based on the variable range found in the data. This research will help to create guidelines on the connection between the barrier island scales & configurations and the level of flood mitigation that can be expected by them. Community leaders, coastal planners, and engineers, could use these guidelines to inform their coastal restoration projects given the communities’ location and needs.”
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An Appraisal of U.S. Coastal Hazards and Diversity, Equity, and Inclusion: Identifying Successes, Needs, and Significant Changes in State and Territory Coastal Management Programs
Christina Mueller
Christina Mueller
University of South Carolina
Mueller is a senior at the University of South Carolina Honors College majoring in Marine Science with a concentration in Coastal Resource Management and Policy and minoring in Political Science and Geography. As a recipient of the 2020-21 NOAA Ernest F. Hollings Scholarship, Mueller completed her summer internship with the NOAA Office for Coastal Management. Her project focused on the overlap between coastal hazards and diversity, equity, and inclusion. On campus she is also involved in the South Carolina Student Legislature, SC American Water Works Association Student Chapter, NCAA/NCEA Equestrian Team, orchestra, and faculty research as a Magellan Scholar.
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Abstract
Abstract
Since 1990, states and territories have had the opportunity to participate in the Coastal Zone Enhancement Program under Section 309 of the Coastal Zone Management Act (1972). Through this program, state and territory Coastal Management Programs (CMPs) complete Assessment and Strategy Reports in five year cycles. There are nine enhancement areas outlined in Section 309, however, this review focuses specifically on program needs and priorities related to coastal hazards. The first objective of this review was to obtain a national snapshot of the most significant coastal hazards identified by CMPs in the 2021-2025 cycle. Each of the 32 Coastal Management Programs that submitted a report ranked coastal hazards as a high priority and identified what types of coastal hazards were of most concern. A review of these reports found that flooding, coastal storms, and shoreline erosion were the top hazards nationally. The most common emerging issue was Sea Level Rise/Great Lakes level change. Additionally, this review summarized common hazard management approaches, significant changes in hazard management, and priority needs of management programs such as “Mapping/GIS/modeling” and “Communication and Outreach.” In light of Executive Order 13985, the second objective of this review was to analyze how CMPs address diversity, equity, and inclusion. A keyword search identified 33 active examples and 12 future plans of advancing diversity, equity, and inclusion through the Coastal Zone Enhancement Program. Of these DEI considerations, 40% were specifically linked to coastal hazards. The CMPs’ priorities determine what the National Coastal Zone Management Program should focus support on in order to continue protecting people and the coastal environment.
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Near-prototype experimental framework for observing the physical behavior of variable density munitions in swash and inner surf zones under extreme storm events
Temitope Idowu
Temitope Idowu
Center for Applied Coastal Research, University of Delaware
Temitope Idowu is currently a doctoral student at the center for applied coastal research (CACR), University of Delaware. His broad research interests are in the sustainability of coastal environments, objects migration in the nearshore, coastal processes and the application of GIS in environmental research. He currently works with Dr. Jack Puleo in developing novel insights on the mobility, burial and exposure of variable density munitions in inner surf and swash zones.
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Abstract
Abstract
Extreme storm events have far-reaching impacts beyond ecological changes and economic damages. One of the impacts is the re-appearance of unexploded ordinance (UXOs; also called munitions) on beaches and coastlines. Much of the current body of research on the physical behavior of munitions focuses more on deeper water. However, there are burgeoning interests among the public and government personnel on the behavior of munitions in shallow nearshore environments, namely the swash and inner-surf zones. The physical behavior of munitions (exposure, burial, and mobility) in these regions remains poorly understood. Compounding this poor understanding is that munition characteristics can also change after decades spent underwater due to biofouling, encrustation, and corrosion. These biological and chemical processes alter the bulk density, shape, and roughness that in turn influence migration and burial. We aim to quantify the hydrodynamic forces during simulated extreme storm events that lead to variable-density munitions mobility, exposure, and/or burial in the inner surf and swash zones. We plan to develop improved parameterizations for onshore/offshore motion and/or exposure/burial as a function of forcing conditions and munitions bulk density. A near-prototype experiment will be conducted in a 120 m x 5 m x 5 m piston-type outdoor wave flume located in the Environmental Hydraulics Laboratory, Institut National de la Recherche Scientifique, Québec Metro High Tech Park, Canada. The wave flume is designed for modeling the interactions of waves, tides, currents, and sediment transport. An undistorted scaling analysis is used to obtain the scaling parameters between the morphodynamics of the prototype beach profile (Mantoloking Beach, NJ) and the model profile in the wave flume. XBeach, an open-source nearshore processes numerical model for computing coastal responses to time-varying extreme storm events, is used to establish locations for initial cross-shore positions of munitions and sensors. An overview of the experiment and the adopted dimensionless parameters for ensuring dynamic similitude between the prototype and model will be discussed.
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Modeling future hydrodynamics and morphodynamics of living shoreline project at Little Lagoon, Alabama using XBeach
Elizabeth Winter
Elizabeth Winter
University of South Alabama
Elizabeth Winter is a M.S. student in Coastal Engineering at the University of South Alabama. She received her B.S. in Marine and Organismal Biology from Spring Hill College before coming to the University of South Alabama in Fall 2019.
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Abstract
Abstract
Little Lagoon is a shallow, single inlet lagoon located in Baldwin County, Alabama that has been experiencing shoreline erosion for the past 28 years. The lagoon is approximately 12.5 kilometers long (east to west), and 1 kilometer across (north to south) at its widest point. A living shoreline using vegetation only (Juncus roemerianus and Spartina alterniflora) is being implemented in the southwest corner of the lagoon, located within Bon Secour National Wildlife Refuge, to mitigate erosion and contribute to habitat protection. This study will model future hydrodynamics and morphodynamics at the project site into the future by using XBeach in a 1-dimensional, transect based, mode. This will be done using a Monte Carlo simulation technique in a probabilistic framework and include the effects of sea level rise. This study will predict the long term performance of vegetation only living shorelines and include the effects of storms and sea level rise on the shoreline. The results from this project will aid practitioners in the future design and implementation of living shorelines.
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Modeling of Intra-Event Processes on Barrier Beach
Olivia Amante
Olivia Amante
University of Delaware
I am a master’s student at the University of Delaware working with Dr. Jack Puleo. I grew up in Rhode Island where I also attended the University of Rhode Island, where I obtained a degrees in ocean engineering and marine biology. My field of research is in extreme storm modeling and monitoring; specifically analyzing the morphological changes that occur to the coastline caused by extreme events. I like to think I am a climatologist. What excites me about my research is that we are analyzing a prevalent issue in today’s world; climate change is increasing the frequency of extreme events.
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Abstract
Abstract
“Olivia Amante, University of Delaware, oamante@udel.edu
Evan Mazur, University of Delaware, emazur@udel.edu
Jack Puleo, University of Delaware, jpuleo@udel.edu
Brett Webb, University of South Alabama, bwebb@southalabama.edu
Stephanie Smallegan, University of South Alabama, ssmallegan@southalabama.edu
Evan Mazur, University of Delaware, emazur@udel.edu
Jack Puleo, University of Delaware, jpuleo@udel.edu
Brett Webb, University of South Alabama, bwebb@southalabama.edu
Stephanie Smallegan, University of South Alabama, ssmallegan@southalabama.edu
The USA comprises over 95,000 miles of shoreline and roughly 59% of the coastline is sheltered from the open ocean (e.g. estuaries, bays, lagoons) (NOAA 2020). Barrier islands are sand island strips that shelter approximately 10% of the world’s coastlines (Linhoss, 2018). Being directly exposed to the open ocean, they are vulnerable to energetic ocean events such as extreme storms and hurricanes, which influence the wave and current action that shape the feature (Wang et al., 2015). However, despite their vulnerability, barrier islands are often highly developed and populated. Thus extreme events have caused billions of dollars in infrastructure damage over the past decade (Kobell, 2015). There has been a notable rise in extreme storms over the past decades with damages also increasing with effects of sea-level rise (Kobel 2015).
Survey data can be used to measure morphological changes pre- and post-storm, but data on the hydrodynamic and morphodynamic processes that shape the beach during the event are sparse. Understanding intra-event storm processes may assist in improving predictive models on the effects of extreme events on barrier island morphodynamics. XBeach is a 2-dimensional modeling system that simulates morphodynamic processes using depth-integrated and short-wave average hydrodynamics to predict bathymetric behavior during extreme events (Roelvink et al. 2009). Xbeach was used to model the domain of Bethany Beach, DE an area which falls victim to extreme Nor’Easter events annually. Simulations were forced using wave information from a NOAA buoy located roughly 11 km offshore. Simulations were run to determine beach response for multiple past extreme events. Additional simulations undertook varying mean wave angle, wave height, and water level to determine the effect on beach morphology. Eventually, data from the 2021/22 Nor’Easter season will be used to calibrate XBeach for intra-event processes and quantify the time scales of beach erosion and effect of berm lowering on morphodynamic processes.
References
Kobell, R. 2015. “For Vulnerable Barrier Islands, A Rush to Rebuild on U.S. Coast”. YaleEnviorment360.
Linhoss. A. 2018. “Barrier islands are natural coast guards that absorb impacts from hurricanes and storms” The Conversation.
NOAA. 2020. “Shoreline Mileage of the United States.”
Sallenger, A. 2000. “Storm Impact Scale for Barrier Islands”. Journal of Coastal Research, vol.16, no. 3.
Roelvink, J.A. et al. 2009. “Modelling storm impacts on beaches, dunes and barrier islands”. Coastal Engineering 56, 1133–1152.
Wang et al. 2015. “Chapter 10 – Storm-Induced Morphology Changes along Barrier Islands and Post Storm Recovery”. Coastal and Marine Hazards, Risks, and Disasters.”
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The United States response to new emissions abatement technology in the maritime shipping industry
Boluwatife Owoeye
Boluwatife Owoeye
National Oceanic and Atmospheric Administration
B. Eni Owoeye is a fourth year student at New York University studying International Relations and Environmental Science with a minor in Spanish. As a 2020 Ernest F. Hollings Scholar, she conducted work with the Office of International Activities within NOAA’s Oceanic and Atmospheric Research division. She also serves as the co-chair of the U.S. Youth Advisory Council to the U.N Decade of Ocean Science. She has a keen interest in ocean-climate nexus issues and environmental justice.
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Abstract
Abstract
The United States’ influential maritime heritage began in the country’s early colonial period. Today, shipping remains crucial to the global supply chain and an important engine for domestic and international trade growth. In order to protect public and ecological health in marine and coastal regions, the industry should adopt new regulations and technologies to achieve sustainable shipping. It is well documented that fine particulate matter, sulfur oxides (SOx), and nitrogen oxides emitted from ship smokestacks lead to premature mortality and morbidity effects.
Exhaust gas cleaning systems, or scrubbers, on ships are gaining popularity as a strategic alternatives to combating air pollution while complying with the current International Maritime Organization (IMO) requirements for SOx content in marine fuel exhaust. This paper will analyze literature documenting the increase of scrubber implementation on vessels and the environmental and public health considerations. I also observe the federal policy framework to regulate and enforce standards for these systems, with case studies into California, Connecticut, and Florida as well. According to one study, only five scrubbers were applied to marine vessels prior to 2010. In 2018, the cumulative number of vessels to be installed or under contract reached over 1,200. Many select open-loop or hybrid wet scrubbers to install, leading to some concerns over the accumulation of wash water discharge, especially in heavy traffic areas. This comparison between the national and statewide responses demonstrates California and Connecticut’s preemptive action against detrimental effects scrubbers cause through their discharge, while Florida displays the potential disproportionate harm done if scrubber discharge procedures remain unchecked. Finally, I look at the U.S. Environmental Protection Agency’s non-compliance data from 2013-2020 for registered permit holding vessels with scrubbers onboard to track most serious perpetrators of violations.
The United States should encourage an efficient and sustainable intermodal shipping industry both domestically and abroad. A lack of research conducted within the United States pertaining to exhaust gas cleaning system efficiency, wash water effluents, and potential policy frameworks for regulating scrubbers leave gaps of knowledge. The scientific community in the United States can explore future scenarios of ship emissions and the use of open-loop scrubbers, combined with modelled deposition from ships and other sources. Additionally, as a member of multilateral organizations like IMO and the U.N, the United States has a strong case for coalescing international cooperation against excessive scrubber discharge dumpings. Desulfurization within the shipping industry will not be solved with one solution. Further development and research into alternative, cleaner fuel sources and abatement methods like scrubbers will position marine vessels to adequately adapt to a changing climate and vulnerable aquatic environments. The United States could face destabilizing concentrations of nitrates, polycyclic aromatic hydrocarbons, and heavy metals without proper coordination to ensure effective management of scrubber usage within U.S waters.
Exhaust gas cleaning systems, or scrubbers, on ships are gaining popularity as a strategic alternatives to combating air pollution while complying with the current International Maritime Organization (IMO) requirements for SOx content in marine fuel exhaust. This paper will analyze literature documenting the increase of scrubber implementation on vessels and the environmental and public health considerations. I also observe the federal policy framework to regulate and enforce standards for these systems, with case studies into California, Connecticut, and Florida as well. According to one study, only five scrubbers were applied to marine vessels prior to 2010. In 2018, the cumulative number of vessels to be installed or under contract reached over 1,200. Many select open-loop or hybrid wet scrubbers to install, leading to some concerns over the accumulation of wash water discharge, especially in heavy traffic areas. This comparison between the national and statewide responses demonstrates California and Connecticut’s preemptive action against detrimental effects scrubbers cause through their discharge, while Florida displays the potential disproportionate harm done if scrubber discharge procedures remain unchecked. Finally, I look at the U.S. Environmental Protection Agency’s non-compliance data from 2013-2020 for registered permit holding vessels with scrubbers onboard to track most serious perpetrators of violations.
The United States should encourage an efficient and sustainable intermodal shipping industry both domestically and abroad. A lack of research conducted within the United States pertaining to exhaust gas cleaning system efficiency, wash water effluents, and potential policy frameworks for regulating scrubbers leave gaps of knowledge. The scientific community in the United States can explore future scenarios of ship emissions and the use of open-loop scrubbers, combined with modelled deposition from ships and other sources. Additionally, as a member of multilateral organizations like IMO and the U.N, the United States has a strong case for coalescing international cooperation against excessive scrubber discharge dumpings. Desulfurization within the shipping industry will not be solved with one solution. Further development and research into alternative, cleaner fuel sources and abatement methods like scrubbers will position marine vessels to adequately adapt to a changing climate and vulnerable aquatic environments. The United States could face destabilizing concentrations of nitrates, polycyclic aromatic hydrocarbons, and heavy metals without proper coordination to ensure effective management of scrubber usage within U.S waters.
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Adaptation Strategies to Mitigate Impacts of Sea Level Rise on a Freshwater Aquifer Supply on a Barrier Island
Kaylyn Bellais
Kaylyn Bellais
University of South Alabama
Kaylyn received her Bachelors of Science in Geology from the University of South Alabama in Mobile, Alabama and is currently pursuing a Masters of Science in Coastal Engineering at the University of South Alabama. She is a native of Biloxi, Mississippi and has enjoyed spending her childhood at some of the Mississippi Barrier islands (Horn and Ship Island) beach-combing and looking for shark teeth.
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Abstract
Abstract
Coastal breaching can result in saltwater intrusion to coastal aquifers which supply freshwater to residents. Adaptation strategies are used to minimize breaching in response to storms and sea-level rise (SLR). An adaptation tipping point for a barrier island is said to exist when an adaptation strategy fails, and the island can no longer avoid breaching due to frequent storm occurrence and increasing sea-levels. Previous studies have applied statistics to identify adaptation tipping points and construct adaptation pathways as a function of quantity of SLR. This study is focused on Alligator Lake on the barrier island Dauphin Island, AL; a site residents and community leaders identified as a vulnerable to breaching under future SLR conditions. Therefore, the purposes of this study are to numerically simulate impacts of a storm and SLR scenarios on a barrier island freshwater aquifer, evaluate the effectiveness of adaptation strategies to protect saltwater intrusion of the aquifer as sea levels rise, and develop an adaptation pathway for protecting the freshwater supply under future climate scenarios. XBeach was used to simulate morphological changes to the region near Alligator Lake with merged DEM and Lidar data. Hydrodynamic forcings included Hurricane Nate water levels recorded from the Dauphin Island tide gauge 8735180, and spectral wave conditions recorded from NOAA data buoy station 42012. SLR scenarios (0.4 m, 0.53 m, 0.66 m, 1.0 m, 1.26 m, and 1.93 m) were simulated with Hurricane Nate hydrodynamic conditions. Manning’s roughness coefficients were used as a model input to account for frictional losses from land cover and open water. This poster will present results on quantitative differences between initial and final bed elevations and changes in bed elevations generated in MATLAB for Alligator Lake in response to Hurricane Nate and SLR scenarios. Future work will include simulating adaptation strategies and creating an adaptation pathway. This study will contribute to adaptation management and policy through stakeholder involvement to protect the freshwater supply on the east end of Dauphin Island.
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Pressure Gradients Under Double Dam Break Driven Swash
Courtney Olney
Courtney Olney
University of Delaware
I am a master’s student at the University of Delaware working under Dr. Puleo investigating the hydrodynamics on dam-break-driven swash. Other research interest of mine includes hydrology, numerical modeling, coastal flooding, and sea-level rise. I have a background in water resources as I worked for an engineering consultant firm for two years prior to starting my masters.
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Abstract
Abstract
Swash zone processes drive foreshore morphodynamics through sediment transport gradients. Sediment transport rates are often estimated using bed shear stress as the main hydrodynamic driver. Nevertheless, past work in the surf zone using closely spaced miniature pressure sensors has shown that the bed might also momentarily fail under strong pressure gradients (Anderson et al., 2017). Thus, it is important to investigate the relative importance (magnitude and phasing) between pressure gradient and bed shear stress over the swash cycle. Prior efforts investigated swash zone pressure gradients using the instantaneous water surface slope (Baldock et al., 2006) or pressure sensors (Suzuki et al., 2010). However, the importance of the pressure gradient relative to the bed shear stress in the swash zone is still poorly known.
Many recent studies have reproduced swash motions in laboratory facilities at near prototype scale using a dam break mechanism (Kikkert et. al. 2012; O’Donoghue et. al. 2010). Bore generation is created by the quick release of a water reservoir, inundating the dry beach area. Here, we used a double dam break to identify the relative importance of pressure gradients and bed shear stress in the swash zone under bore interaction. Experiments were conducted in the wave flume at the Center for Applied Coastal Research at the University of Delaware using an impermeable, steep (1:7) fixed sloped beach. Swash interactions were investigated by varying the time (0 to 3 s) between the release of the two dam break reservoirs. Seven cases varying the release time were tested with 10 repetitions each for a total of 70 trials using a smooth bed. Bed roughness effects on foreshore hydrodynamics will be further investigated by completing additional experiments using a fixed rough bed. Water depths measurements were recorded using twelve ultrasonic distance meters (Massa). Offshore velocity measurements were made using two acoustic Doppler profiling velocimeters (Nortek; ADPV). Velocities on the beach slope were obtained using six electromagnetic current meters (Valeport; EMCM). A new pressure sensor array using seven miniature pressure sensors (TE Connectivity) was deployed at the toe of slope. The sensors are separated by 0.03 m with gradients quantified using finite differences. The measured data were ensemble averaged over time and space for each case. Bed shear stress estimates will be calculated based on the quadratic drag law with the EMCM data and compared against estimates from the log-law method for the ADPV data. The experimental data collected will determine the relative importance of bed shear stress and pressure gradients as a function of cross-shore distance, swash phase and interaction intensity.
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An Idealized Numerical Model of Carmel River Beach’s Bar-Built Estuary
Nicole Nguyen
Nicole Nguyen
United States Naval Academy
Midshipman Nicole Nguyen is studying Ocean Engineering at the United States Naval Academy. She will graduate and commission as an officer in the US Navy in May 2022.
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Abstract
Abstract
“Carmel River Beach, California, is part of a bar-built estuary that experiences significant morphological changes owing to beach breaching. Previous research shows that precipitation, discharge, wave forcing, and tidal exchange all contribute to beach breaching, but to what extent is unknown. During heavy precipitation or river discharge, water levels of the river and lagoon rise, resulting in unpredictable flooding that can damage coastal properties. The objective of this research is to develop an idealized numerical model of the Carmel River Beach system to better understand and predict the effects of tides, river discharge, and waves in breached bar- built estuaries.
The model was built using Delft3D, bathymetry data were obtained from previous studies, and boundary conditions of external forcings were obtained from historical records in the closest tidal, wave, and river discharge gauges to the study site. A sensitivity analysis was performed and included a range of values for river discharge and wave heights plus their peak periods. After processing the outputs, conclusions were drawn specifically for bar-built estuaries that are already breached and contain an open inlet.
Results suggest that during ebb tide, depth-averaged velocity increases with river discharge. Waves have a greater effect on water levels in the lagoon compared to river discharge as long as the inlet is open. Additionally, an increase in either river discharge or wave height will also increase the overall maximum discharge that flows out of the inlet. The main findings were: (1) Increase in depth-averaged velocities due to river discharge could lead to longer inlet durations. (2) Higher waves increase water levels in the lagoon, which affects coastal flooding. (3) Increase in either wave height or river discharge increases the total max ebb discharge through the inlet.
Next steps for research could include running simulations to test the effects of changing bathymetry and sediment transport in the dynamics of the beach. The sensitivity analysis completed here, could also be expanded by simulating a broader range of values for both river discharge and wave height. In the future, the results of this study can be expanded by comparing it to other bar-built estuaries located in different regions.”
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*Virtual Participant
Using Mobile Lidar and a 360-Degree Spherical Camera for Rapid Assessment of Beach and Foredune Elevation Change After Hurricane Hanna on North Padre Island, Texas, USA
Isabel Garcia
Isabel Garcia
Texas A&M University – Corpus Christi
Isabel Garcia graduated from New Mexico State University in 2015 with a B.S. in Surveying Engineering. She continued her education at Texas A&M University – Corpus Christi (TAMUCC) completing, her M.S. in Geospatial Surveying Engineering in 2018. She is currently studying to complete her Ph.D. in Coastal and Marine Systems Science at TAMUCC. Her current research focuses on mobile lidar development and utilization of mobile lidar systems (MLS) to monitor coastal changes and rapid post-storm analysis.
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Abstract
Abstract
” Hurricane Hanna made landfall on July 25, 2020, around 5:00 P.M. Central Daylight Time as a Category 1 hurricane on North Padre Island, Texas, USA. This storm was the first of its kind in the 2020 Atlantic Hurricane Season, developing weeks before any H-named storms in previous seasons. Maximum sustained winds of 150 km/h were recorded at the time of impact. North Padre Island experienced a storm surge of up to 2 meters in some areas and experienced substantial flooding. Storm surge along with strong winds and wave impact resulted in a rapid change in the beach and foredune structure. The purpose of this study is to rapidly assess elevation changes in the beach and foredunes along a stretch of sandy beach along North Padre Island with a mobile lidar system (MLS).
The system used in this study is called the HiWay Mapper, integrated by LidarUSA, and consisting of two parts: Snoopy system and a FLIR Ladybug 360-Degree Spherical Camera. The Snoopy consists of a Velodyne HDL-32E lidar, a NovAtel GNSS 702gg antenna, and a SPAN-IGM inertial navigation system (INS). The Velodyne contains 32 Class 1, 903nm laser pairs situated in a rotating head. It has a 40° vertical field of view (FOV), a 360° horizontal FOV, records up to ~700,000 per second in single return mode, and has an effective range of 100m. The SPAN-IGM INS contains 3 accelerometers, 3 gyroscopes, and collects at 125 Hz. The Ladybug is a 360-degree camera with 6 lenses and can record up to 30 frames per second (FPS) and captures 90% of a full sphere. Post-Hanna MLS data was collected on August 4, 2020, 10 days after Hanna made landfall. The total length of beach that was surveyed was ~11km. The data was post-processed and from it, a digital elevation model (DEM) was generated. Georeferenced ground control points (GCPs) were used to compare the system’s accuracy and were integrated in post processing to achieve a more accurate product. The comparison data was pre-Hanna airborne topo-bathymetric lidar data collected in 2018 by the United States Geological Survey (USGS) with pulse spacing of 0.7 meters and downloaded as a 1 m bare-earth DEM. These two datasets were compared to determine beach and foredune elevation changes after hurricane Hanna. Results showed that a significant elevation change occurred, particularly in the foredunes.”
The system used in this study is called the HiWay Mapper, integrated by LidarUSA, and consisting of two parts: Snoopy system and a FLIR Ladybug 360-Degree Spherical Camera. The Snoopy consists of a Velodyne HDL-32E lidar, a NovAtel GNSS 702gg antenna, and a SPAN-IGM inertial navigation system (INS). The Velodyne contains 32 Class 1, 903nm laser pairs situated in a rotating head. It has a 40° vertical field of view (FOV), a 360° horizontal FOV, records up to ~700,000 per second in single return mode, and has an effective range of 100m. The SPAN-IGM INS contains 3 accelerometers, 3 gyroscopes, and collects at 125 Hz. The Ladybug is a 360-degree camera with 6 lenses and can record up to 30 frames per second (FPS) and captures 90% of a full sphere. Post-Hanna MLS data was collected on August 4, 2020, 10 days after Hanna made landfall. The total length of beach that was surveyed was ~11km. The data was post-processed and from it, a digital elevation model (DEM) was generated. Georeferenced ground control points (GCPs) were used to compare the system’s accuracy and were integrated in post processing to achieve a more accurate product. The comparison data was pre-Hanna airborne topo-bathymetric lidar data collected in 2018 by the United States Geological Survey (USGS) with pulse spacing of 0.7 meters and downloaded as a 1 m bare-earth DEM. These two datasets were compared to determine beach and foredune elevation changes after hurricane Hanna. Results showed that a significant elevation change occurred, particularly in the foredunes.”
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The benefits and limitations of using UAS-SfM versus lidar to monitor coastal environments
Kelsi Schwind
Kelsi Schwind
Texas A&M University – Corpus Christi
Kelsi Schwind is a doctoral student pursuing her degree in Coastal and Marine System Sciences at Texas A&M University – Corpus Christi. She is a member of the Measurement Analytics Lab and Conrad Blucher Institute for Surveying and Science. Currently, her work focuses on fusing remotely sensed data and using GIS for the purposes of monitoring coastal processes.
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Abstract
Abstract
As the development of unmanned aircraft systems (UAS) platforms continues to advance, the possibilities of utilizing this technology as a substitute, or in conjunction with, more expensive remote sensing techniques continues to be explored. The affordability and flexibility of such systems offers unique advantages that can be useful for numerous coastal monitoring efforts. This research discusses the respective benefits and limitations of using UAS structure-from-motion (SfM) for the purposes of examining coastal environments. The respective benefits and limitations of using UAS-SfM on the coast are derived from relevant literature and personal research that utilizes this technology to generate elevation models which are used in conjunction with elevation models produced by airborne lidar to quantify the impact of Hurricane Michael on a Floridian barrier island and its respective short-term recovery.
UAS surveys were conducted to acquire high-resolution imagery both prior to, and following, the impact of Hurricane Michael on Little St. George Island, Florida. The images were processed using SfM photogrammetric techniques to derive 3D point clouds and digital elevation models (DEMs) that were utilized to quantify the storm impact and island’s recovery in conjunction with an elevation model generated using topobathymetric lidar data acquired by the Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX). To investigate the storm impact, net shoreline movement, evolution of the dune crest and beach width, and volumetric change detection were evaluated using the DEMs.
The use of UAS-SfM derived data products for goals of this study had respective benefits and limitations that should be considered for the purposes of future research objectives. Benefits of utilizing the UAS platform include affordability, and thus the capability to survey with greater frequency and flexibility than is often possible with other, more costly methods such as lidar at smaller spatial scales such as this study. The derived UAS-SfM elevation models were higher resolution than publicly available data and achieved greater vertical accuracy when compared against a series of bare-earth independent check points. Additionally, the acquisition of high-resolution imagery also can also be used to produce data products such as orthomosaics to further enhance analyses. However, certain limitations should be considered. The inability to derive multi-return point clouds results in inherent vegetation bias that may still affect results, even with the implementation of advanced ground filtration. Additionally, surveys with the UAS can be timely, which resulted in the inability of timing UAS surveys at specific tidal conditions for the entirety of the image acquisition process. Thus, the limitations must be considered for future studies to determine if employing UAS-SfM is suitable for the scope of the research goals.
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Evaluating UAS-SfM Software and Workflows for Shoreline and Elevation Mapping
Jose Pilartes-Congo
Jose Pilartes-Congo
Texas A&M University – Corpus Christi
Mr. Pilartes-Congo is pursuing a master’s degree in Geospatial Systems Engineering at Texas A&M University – Corpus Christi. His research focuses on evaluating various UAS positioning technologies and processing workflows for surveying coastal environments.
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Abstract
Abstract
In recent times, Unmanned Aircraft Systems (UAS) and Structure-from-Motion (SfM) technologies have significantly reduced the amount of time and human labor needed for topographic mapping, particularly in coastal environments. The accuracy of coastal surveys depends heavily on the georeferencing method and SfM software used for data processing. Today, one of the biggest challenges of UAS-SfM is the limited research about the impact of the processing software on the accuracy of elevation models. This study explores the differences in UAS-SfM derived digital elevation models (DEMs) as influenced by the SfM software used for processing. The study uses a set of UAS acquired data from Mustang Island, Texas (using a WingtraOne UAS platform), georeferenced using Post-Processed Kinematic (PPK) corrections, and processed using three commercial software (Drone2Map, Pix4Dmapper, and Metashape) and one open-source software (OpenDroneMap). Advantages and limitations of each software are drawn, and resulting products are evaluated against each other in terms of RMSE values and overall quality of DEMs. Results are aimed at increasing awareness about the various software and will benefit other UAS users in the community, especially those involved in coastal monitoring.
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Testing Living Shoreline Elements under Ship Wake Forces on an Estuarine Island
Cassandra Everett
Cassandra Everett
University of Delaware
Cassandra Everett is an aspiring coastal engineer pursuing a Master’s degree in coastal engineering at the University of Delaware, working under Dr. Jack Puleo and studying the response of living shoreline elements under ship wake forcing. She received her undergraduate degree in civil engineering from the University of Southern California. Her research interests include ship-wake-induced morphodynamics, living shorelines and nature-based solutions, and coastal resiliency.
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Abstract
Abstract
“Living shorelines have long been used in estuarine environments to mitigate erosion from natural stressors such as wind-induced waves. These implements, primarily composed of natural and sustainable materials, serve the purpose of protecting shoreward vegetation from low to moderate wave energy. However, less research has been conducted to investigate the efficacy of living shorelines in addressing erosion due to ship wake from commercial vessels, which can be more energetic than background conditions. This study aims to better understand living shoreline response in estuaries with high commercial shipping traffic. As such, this study was conducted on Pea Patch Island on the Delaware River. Thousands of commercial vessels navigate the river each year through the shipping channel located ~100 m from the eastern shoreline of Pea Patch Island. Vessel traffic frequency means ship wake events occur on a daily basis, so living shoreline approaches must be robust to withstand these wake events. However, the frequency of vessel traffic also provides ample opportunity for data collection and model validation.
Two pilot studies, in addition to analysis performed using the FUNWAVE-TVD model, informed the design of a larger installation on the island which was completed in June 2021. The installation consisted of four T-head groins composed of ten coir logs each and ~300 individual marsh grass plantings. Eight pressure sensors and electromagnetic current meters were deployed to obtain the cross-shore and longshore evolution of hydrodynamics in the vicinity of the installation. Field data were compared across structures to determine energy dissipation as a function of tidal level. Data were also compared to expected energy dissipation of breaking waves over a sloping beach.
Data from the installation were also used to evaluate the effectiveness of FUNWAVE-TVD in predicting the wave attenuation produced by the living shoreline in response to ship-wake. FUNWAVE-TVD is a total variation diminishing version of the nonlinear Boussinesq FUNWAVE model. FUNWAVE-TVD contains a ship-wake generation module, developed in 2018, which has been previously validated against lab and field data. The US Army Corps of Engineers has provided extensive information regarding vessel traffic along the channel during data collection periods. These data enabled further model validation based on specific vessel size, shape, speed, and course for each wake event during the study. Model skill was quantified using root-mean-squared error between modeled and recorded data.”
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Modeling Shoreline Erosion using DSAS v5.0
John Simmons
John Simmons
Texas General Land Office / Graduate Student – University of Houston Clear Lake
John Simmons is a graduate student at the University of Houston – Clear Lake receiving a degree in Environmental Science with a specialization in Geology. He received his undergraduate degree with honors at the University of Houston from the Honors College in Geology and had dual minors in Chemistry and Geophysics. He currently works for the Texas General Land Office as a Natural Resource Specialist.
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Abstract
Abstract
Objectives: Coastal erosion is a major concern for populations worldwide. That is, the displacement of sediment and rocks from coastlines that lead to retreat of shoreline in a landward direction. This erosion is the result of sea level rise, coastal flooding, wave action, and human interference. The purpose of this study is to quantify the amount of shoreline lost and create a model that displays rates of erosion for areas that may be of specific concern.
Materials and Methods: The DSAS v5.0 add-on for ArcMap was used for this study. Imagery from 1850-2020 was georeferenced and used to calculate transects/erosion rates for the entire Texas Coast. Two rate calculation methods and two models were generated based on linear regression rate and weighted regression rate.
Results: The model was accurately able to produce sedimentation rates at regional and even these localized scales. The erosion rate for the Texas Coast as a whole is alarmingly high. The average rate according to the linear regression method is 0.685879 m/yr and according to the weighted regression method 0.731229 m/yr. The average net shoreline movement from 1850 to 2020 is -111.788516 meters. This is for the entire Texas coast and corresponds to meters of shoreline lost in that time period. The maximum shoreline movement in some areas was predicted to be as high as 2092.63 m (shoreline gained) and as low as -1704.86 m (shoreline loss). The weighted linear regression method provided a much higher quality model when compared to the linear regression method. The average standard error in the linear regression was 52.1582 meters while in the weighted regression method it was only 5.575171 meters. This is due to the larger amount of weight assigned to more reliable data.
*There are also site-specific examples of the model and how accurately it has predicted erosion/accretion in some areas including the new mouth of the Brazos and Sargent Beach*
Conclusions: Based on the model and calculated values, the erosion in Texas should be considered a major concern. The trends of accretion and erosion indicate that a major driving force could be the interruption of natural longshore drift patterns by anthropogenic forcings. Another factor that needs to be considered is the increasing number and severity of storm events.
Source of Funding: None
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Depth of Closure and Its controlling Factors at Various Florida Beaches
Elizabeth Royer
Elizabeth Royer
University of South Florida
Elizabeth Royer is a graduate student working in the Coastal Research Laboratory under Dr. Ping Wang at the University of South Florida, pursing a master’s degree in Geology. Royer obtained her undergraduate degree in Geology and Environmental Studies from Oberlin College in 2020. Royer’s research interests include nearshore sediment transport, beach morphodynamics, coastal engineering and management, and coastal sedimentary processes.
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Abstract
Abstract
“Depth of closure is defined as the most landward depth seaward of which there is no significant change in bottom elevation and no significant net sediment exchange between the nearshore and the offshore over a certain period of time, such as 5 to 20 years. This is an essential piece of information for coastal engineering, beach and shore protection, sediment management, and many other aspects of coastal studies. Taking advantage of recent advancements in wave hindcast and bathymetry data collection, this study aims to develop a new and more comprehensive method to identify the depth of closure through field measurements, in order to evaluate and improve existing empirical formulas, and to examine the influences of storm surge, both positive and negative.
Time-series beach profiles from 9 different study sites along the Florida coast, including two from the north coast, two from the west coast, and five from the east coast, were analyzed to determine the depth of closure based on repetitive surveys. These 9 study sites cover a wide range of coastal morphodynamic conditions, with considerable difference in tidal ranges, incident wave heights, as well as nearshore and offshore slopes. Over the past fifteen years, the accuracy and frequency of offshore profile surveys have improved substantially due to the advancement in global positioning technology. This provides a valuable database to determine closure depth. These closure depths obtained from field data were compared to values calculated from the existing formulas in order to assess the formulas accuracy. Hindcast wave data from WAVEWATCHIII, available since 2005, were extracted from the above sites to calculate the closure depth using various empirical equations. The computed closure depth is compared with the measured closure depth. The empirical formulas were evaluated based on the comparison with the measured data. In addition to comparing with existing empirical formulas, the relationship between the measured closure depth and various hydrodynamic and morphological factors is examined systematically.
Progressive analyses reveal that extreme wave height, for example, 12-hr exceedance height, and foreshore slope play significant roles in closure depth. Extreme wave height has been used in most empirical formulas, while foreshore slope has not. This study is funded by the US Coastal Research Program. This poster presents our first-year results from this two-year study. Continued study will examine the influence of storm surge, which would significantly increase water depth and subsequently decrease wave stirring power, on the closure depth. We also intend to expand our study sites beyond the Florida coast.”
Time-series beach profiles from 9 different study sites along the Florida coast, including two from the north coast, two from the west coast, and five from the east coast, were analyzed to determine the depth of closure based on repetitive surveys. These 9 study sites cover a wide range of coastal morphodynamic conditions, with considerable difference in tidal ranges, incident wave heights, as well as nearshore and offshore slopes. Over the past fifteen years, the accuracy and frequency of offshore profile surveys have improved substantially due to the advancement in global positioning technology. This provides a valuable database to determine closure depth. These closure depths obtained from field data were compared to values calculated from the existing formulas in order to assess the formulas accuracy. Hindcast wave data from WAVEWATCHIII, available since 2005, were extracted from the above sites to calculate the closure depth using various empirical equations. The computed closure depth is compared with the measured closure depth. The empirical formulas were evaluated based on the comparison with the measured data. In addition to comparing with existing empirical formulas, the relationship between the measured closure depth and various hydrodynamic and morphological factors is examined systematically.
Progressive analyses reveal that extreme wave height, for example, 12-hr exceedance height, and foreshore slope play significant roles in closure depth. Extreme wave height has been used in most empirical formulas, while foreshore slope has not. This study is funded by the US Coastal Research Program. This poster presents our first-year results from this two-year study. Continued study will examine the influence of storm surge, which would significantly increase water depth and subsequently decrease wave stirring power, on the closure depth. We also intend to expand our study sites beyond the Florida coast.”
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Land subsidence mapping using InSAR at the South Padre Island Area, Texas
Wen Zhong
Wen Zhong
Texas A&M University, Corpus Christi
Wen Zhong received her B.S. and M.S. at Lanzhou University, China. She is presently a Ph.D. student in the Geospatial Computer Science Program at Texas A&M University-Corpus Christi. She is working on her research at the Conrad Blucher Institute. Wen is quantifying surface land subsidence along the Texas coast using Interferometric Synthetic Aperture Radar (InSAR).
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Abstract
Abstract
Relative sea level rise (RSLR) along the Texas Gulf Coast is highly dependent on local rates of land subsidence. Land subsidence occurs due to groundwater/hydrocarbon withdrawal, tectonic activities, soil compaction, the influence of growth faults, other natural processes, etc. Accurate estimates of the magnitude of local land subsidence are very important for long term coastal planning including for coastal structures, flooding and sustainability of ecosystems such as salt marshes and tidal flats. South Padre Island in Texas is home to critical habitat and tourism infrastructure important to the local economy. We selected this area to map the spatial variability of coastal land subsidence. Satellite interferometric synthetic aperture radar (InSAR) is a geodetic technique for monitoring the earth’s surface change over large areas with centimeter-to-millimeter accuracy. Small baseline subset (SBAS) InSAR method utilizes interferograms from small temporal and spatial baseline subsets, thus reducing both spatial and temporal decorrelation. This study used SBAS InSAR to estimate the land subsidence around South Padre Island based on 50 C-band Sentinel-1 SAR images acquired from March 9, 2017 through July 10, 2021. Two areas located in the vicinity of the Brownsville Ship Harbor show larger rates of land subsidence up to 1.48 cm/year in line-of-sight (LOS) direction. In addition, results reveal that some areas of South Padre Island subside with a LOS land subsidence rate of up to 0.95 cm/year. Some areas display land uplift, which indicates the large spatial variability of land subsidence over the study area. The spatial variability of the South Padre Island area is discussed in the context of two other areas analyzed near Rockport and Eagle Point further North along the Texas coast.
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Nutrient inputs and their modification by coastal swashes across a sandy shoreline
Mary Olsen
Mary Olsen
Coastal Carolina University, Department of Marine Science
My name is Mary Olsen and I am a graduate student in Coastal Marine and Wetland Studies at Coastal Carolina University. I have a B.S. in Marine Science with an Applied Mathematics minor. I am from Delta, Pennsylvania.
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Abstract
Abstract
Coastal water quality in the Grand Strand of South Carolina is directly influenced by human activities. Nutrient-rich runoff, stemming from numerous anthropogenic sources, finds its way into coastal waters through freshwater inputs often through tidal creeks, termed swashes, that terminate onto sandy beaches. In order to better describe the amount of nutrient inputs into two such swashes of the Grand Strand, Singleton Swash and White Point Swash, we examined anthropogenic runoff from isolated identifiable point discharges and their nutrient concentrations. Concentrations of dissolved inorganic nitrogen (DIN = the sum of nitrate, nitrite and ammonium) and phosphate in discharge water were significantly higher than those in creek water. However, despite these elevated nutrient concentrations, the discharge rate of such isolated point discharges is minor, and inputs are not significant enough to alter primary channel chemistry due to rapid flow rates. We hypothesize that non-point sources, including groundwater inputs, may play a larger role in nutrient loading in the coastal zone. The next stage of our study will focus on capturing seasonal rates of discharges of both point sources and non-point sources and their nutrient concentrations, in contrast with those of coastal ocean waters, to better determine their role in nutrient loading within the coastal zone. Moreover, we will study the role of photosynthesizers, such as microphytobenthos and submerged aquatic macroalgae, in ameliorating the observed nutrient loads entering this coastal zone.
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Professional Posters
Addressing rising tides through adaptive design: UD’s Coastal Resilience Design Studio
Dr Jules Bruck
Dr Jules Bruck
Jules Bruck, Plant and Soil Sciences
University of Delaware
Dr. Jules Bruck is Professor and Director of Landscape Architecture at the University of Delaware where she conducts research concerning coastal resilience, green infrastructure, and public perception of sustainable landscape practices such as designing for ecosystem services. In April 2018, she co-founded the Coastal Resilience Design Studio and helped to launch the Delaware Resilience Awareness (DelRAP) Project and the Coastal Observer app for citizen scientists. She is a registered landscape architect and a SITES Accredited Professional (AP). She was recently appointed Director of the new Gerard J. Mangone Climate Change Science and Policy Hub.
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Abstract
Abstract
Hazards related to sea-level rise and intensifying storms impact every watershed in Delaware. The hazards of storm surge, chronic flooding, erosion, beach stabilization, and land subsidence affect all Delaware counties and impact municipalities, private residences, public and private enterprise, infrastructure, and recreation across the state. The stability of coastal communities is likely to decrease with the changing climate which will in turn create more complex issues that will require a team-oriented approach to problem-solving. Partnering community members, interdisciplinary experts, and students, the mission of the Coastal Resilience Design Studio (CRDS) at the University of Delaware is to develop new and creative strategies and manage special cases that threaten coastal communities. The CRDS, formed in 2018, is an interdisciplinary team of student designers, researchers, and engineers exploring creative and thoughtful solutions to address these challenges. Project plans addressing issues from nuisance flooding to major beach erosion incorporate green infrastructure and living shoreline design, adaptable structures and landscape plans, as well as policy recommendations related to sustainable land use, planning, and education. University-led studios provide stakeholders access to an open working environment – a place to explore, be creative, and develop plans that lead to better outcomes. The CRDS aims to create space for conversations to be held and resources to be shared among community members, researchers, and experts. Project examples and designs for bolstering resilience in coastal Delaware are shared.
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*Virtual Participant
Beneficial Use of Sand Dredged from the San Francisco Main Ship Channel for Storm-Damage Reduction at Ocean Beach, San Francisco, California
Dr John Dingler
Dr John Dingler
US Army Corps of Engineers
John Dingler graduated from the Scripps Institution of Oceanography with a PhD in Marine Geology (Douglas Inman, thesis advisor). Then he was a coastal scientist at the US Geological Survey (Menlo Park, CA). After retiring, he is in an encore career in the Reemployed Annuitant Cadre at the US Army Corps of Engineers. For the most part, he has been assigned to the San Francisco District Planning Branch where he participates in coastal and dredging projects.
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Abstract
Abstract
To protect the eroding coastal bluff south of Sloat Boulevard at Ocean Beach, San Francisco, sand dredged from the San Francisco Main Ship Channel is being pumped onto South Ocean Beach from a dredge anchored about one mile offshore of the project area. The sand is then being shaped into a berm by earthmoving equipment on the beach. Except near bank-swallow nests, the berm will be built to the bluff top (~30 ft), be ~200 feet wide, and extend ~3,000 feet south from Sloat Boulevard. That configuration requires ~275,000 yd3 of sand. Maintenance dredging of the channel by the US Army Corps of Engineers San Francisco District occurs annually, removing, on average, ~350,000 yd3 of sand. Sand not used to build the berm will be placed in USEPA-designated nearshore placement sites. Construction began in early August 2021 and will be completed by September 30, 2021. The sand placement will protect the bluff and the associated infrastructure from erosion and is expected to last ~6 years before totally eroding into the nearshore. Using its hopper dredge Stuyvesant, the Dutra Group is dredging the Main Ship Channel and building the berm.
In 1852, the Ocean Beach shoreline south of Sloat Boulevard, was situated hundreds of feet landward of its current location. Subsequently, a combination of human activities and winter storms caused significant fluctuations in shoreline position. Construction debris from development in the late 1800s and early 1900s moved the shoreline seaward, and construction of a large wastewater transport pipe resulted in placing ~400,000 yd3 of sand on the beach. Because there are no coastal structures in the project area, intense winter storms have caused significant beach retreat and bluff erosion. Because the bluff consists of unconsolidated sand, which is susceptible to periodic severe erosion, and construction debris, which litters the beach when exposed, the City has repeatedly built rock revetments against the bluff face in areas that had just eroded, leaving other sections of the bluff unprotected. Despite those efforts, the bluff continues to erode, undermining a parking lot and roadway shoulder. Rather than placing more rock on the beach, the City, National Park Service (the landowner), and many residents want bluff protection that does not include revetments.
This Project is being conducted under the Corps’ Continuing Authorities Program Section 204 (i.e., using material dredged from a federal navigation project to reduce storm damage to property). The project goal is to beneficially use the sand to protect the bluff from further erosion that could eventually damage expensive City and County of San Francisco owned wastewater infrastructure within the bluff. The City’s Public Utilities Commission is the non-federal sponsor, and the berm will be built on National Park Service property managed by the Golden Gate National Recreation Area. Although the Section 204 authority specifies that projects are one-time only, the City has requested that the San Francisco District initiate a General Investigations Study to determine the feasibility of multiple beach placements at South Ocean Beach.
In 1852, the Ocean Beach shoreline south of Sloat Boulevard, was situated hundreds of feet landward of its current location. Subsequently, a combination of human activities and winter storms caused significant fluctuations in shoreline position. Construction debris from development in the late 1800s and early 1900s moved the shoreline seaward, and construction of a large wastewater transport pipe resulted in placing ~400,000 yd3 of sand on the beach. Because there are no coastal structures in the project area, intense winter storms have caused significant beach retreat and bluff erosion. Because the bluff consists of unconsolidated sand, which is susceptible to periodic severe erosion, and construction debris, which litters the beach when exposed, the City has repeatedly built rock revetments against the bluff face in areas that had just eroded, leaving other sections of the bluff unprotected. Despite those efforts, the bluff continues to erode, undermining a parking lot and roadway shoulder. Rather than placing more rock on the beach, the City, National Park Service (the landowner), and many residents want bluff protection that does not include revetments.
This Project is being conducted under the Corps’ Continuing Authorities Program Section 204 (i.e., using material dredged from a federal navigation project to reduce storm damage to property). The project goal is to beneficially use the sand to protect the bluff from further erosion that could eventually damage expensive City and County of San Francisco owned wastewater infrastructure within the bluff. The City’s Public Utilities Commission is the non-federal sponsor, and the berm will be built on National Park Service property managed by the Golden Gate National Recreation Area. Although the Section 204 authority specifies that projects are one-time only, the City has requested that the San Francisco District initiate a General Investigations Study to determine the feasibility of multiple beach placements at South Ocean Beach.
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*Virtual Participant
Mandeville Lakefront Wetland Protection and Restoration
Glenn Ledet
Glenn Ledet
Neel-Schaffer Inc.
Glenn Ledet is the Vice President of the Coastal Science & Water Resource division of Neel-Schaffer. Mr. Ledet has approximately 14 years of experience as a program manager, project manager and engineer on a wide variety of civil engineering projects, including comprehensive drainage studies, regional watershed modeling, and flood control projects. Mr. Ledet previously served as Assistant Administrator of the Operations Division for the State of Louisiana’s Coastal Protection and Restoration Authority (CPRA) managing CPRA’s Regional Offices with more than 40 personnel responsible for constructing, operating, monitoring and maintaining the State of Louisiana’s coastal projects.
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Abstract
Abstract
“Mandeville Lakefront Wetlands project is a whole ecosystem restoration project where multiple habitat types are protected, restored, and created. The project site is situated between two “”hard”” shorelines, approximately 50 feet south of a mature cypress forest that is rapidly eroding. This project prevents further degradation of the existing wetlands and restores a functioning ecosystem.
A berm shoreline closure mitigates erosion from wave action from Lake Pontchartrain while also providing functionality by connecting the two “hard” shorelines with a multi-use recreational path. The berm shoreline protection feature provides a reduction of water surface elevations for the 50-, 100-, and 500-yr event through reduction in wave heights and addresses future erosion by significantly reducing the open water fetch from Lake Pontchartrain at the project site.
In addition, the project also provides flood protection through the construction of the diversion channel. This diversion channel will receive the urban storm water from the Galvez and Massena Channel outfalls and will directed the waters through the intertidal marsh and newly created. This rerouting of storm waters through the wetlands allows suspended sediment to settle within the lagoon and marsh areas and will mitigate the effects of saltwater intrusion on the existing wetlands. The newly created wetlands will increase faunal habitats, support fisheries, support bird usage, improve primary productivity at the base of the food chain and improve carbon sequestration. The improved ecosystem will filter the urban sediment that would otherwise be discharged into the lake. “
A berm shoreline closure mitigates erosion from wave action from Lake Pontchartrain while also providing functionality by connecting the two “hard” shorelines with a multi-use recreational path. The berm shoreline protection feature provides a reduction of water surface elevations for the 50-, 100-, and 500-yr event through reduction in wave heights and addresses future erosion by significantly reducing the open water fetch from Lake Pontchartrain at the project site.
In addition, the project also provides flood protection through the construction of the diversion channel. This diversion channel will receive the urban storm water from the Galvez and Massena Channel outfalls and will directed the waters through the intertidal marsh and newly created. This rerouting of storm waters through the wetlands allows suspended sediment to settle within the lagoon and marsh areas and will mitigate the effects of saltwater intrusion on the existing wetlands. The newly created wetlands will increase faunal habitats, support fisheries, support bird usage, improve primary productivity at the base of the food chain and improve carbon sequestration. The improved ecosystem will filter the urban sediment that would otherwise be discharged into the lake. “
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ENGINEERING & ECOLOGY WORKING TOGETHER TO DEVLOPE FUNCTIONAL TIDAL PONDS AND CREEKS IN MARSH CREATION PROJECTS
Nicholas McCoy
Nicholas McCoy
USDA/ Natural Resource Conservation Service
Nicholas McCoy has a Master of Science in Engineering from the University of Louisiana at Lafayette and is a Professional Engineer in Louisiana. Nicholas has multiple years of experience designing and constructing coastal restoration projects.
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Abstract
Abstract
Tidal Ponds and Tidal Creeks can provide a beneficial boost to the biodiversity of newly created marsh. Its critical for Ecologist and Engineers work together. Tidal creeks and ponds support a high population of post-larval and juvenile organisms. The high concentration of these organisms along the marsh edge are what draw the wetland-dependent mammals, wading birds, and other fishes to these highly productive habitats. They come together along the edge of the marsh where concentrations are the highest (Minello, T.J., et al. 1994). It is imperative that we ensure these important ecological attributes of a marsh ecosystem are incorporated in marsh restoration as we continue to restore thousands of acres of marsh every year. Up to 34 bird species of conservation concern use marsh habitat within Louisiana, including wading birds, shorebirds, and passerines (USFWS 2008, Rosenberg et al. 2014).
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*Virtual Participant
Investigating the performance of novel oyster reef materials in Apalachicola Bay, Florida
Dr Nigel Temple
Dr Nigel Temple
WSP USA
Dr. Nigel Temple has over nine years of experience conducting research in coastal and wetland ecology. His experience includes innovative research designed to reduce the costs of restoration projects by designing and implementing low-cost environmental sensing technology and by investigating the effectiveness of various onshore and nearshore restoration designs using green infrastructure elements such as oyster reefs and wetland vegetation.
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Abstract
Abstract
Natural oyster reefs in estuaries have declined worldwide as a result of several potentially interacting factors including anthropogenic (e.g., overharvesting, development) and biological stressors (e.g., disease, predation) with devastating consequences to the important ecosystem services they provide and the local communities they support. These converging factors and the increasing use of natural or hybrid wave breaking structures has created a market for novel reef materials that recruit oysters effectively while also attenuating waves. These materials are attractive to small-scale landowners and large-scale coastal land managers since they are often easier to install compared to contemporary materials (i.e., rock and recycled concrete) and include features designed to maximize oyster recruitment. For example, most products are much lighter than rocks (by volume), can be installed easily without heavy equipment, and often include features designed to provide refuge for developing oysters. However, the performance of these materials is rarely evaluated holistically in terms of oyster recruitment, wave attenuation, longevity, and stability. This lack of performance data limits the widescale use of these materials and hinders the identification of scenarios favoring various material features. To begin to address this data gap and investigate the feasibility of using novel materials in a large-scale restoration project in Apalachicola Bay, FL, WSP USA, in partnership with the Apalachee Regional Planning Council, began a coupled field and model-based investigation of the performance of several novel materials. Tested materials include popular novel materials such as those cast from concrete-soaked natural fibers (hereafter, “fibrous materials”), and two types of cast concrete mound structures (hereafter, “mounds”), and contemporary rubble rock for comparison. The field-based component of the study will focus on oyster recruitment comparisons as determined using quadrat surveys of oyster size frequency densities, wave attenuation using low cost gauges, and general assessments of structure integrity following project construction (expected 2022). However, a pilot study comparing oyster recruitment to fibrous materials, rocks and concrete (i.e., comparable to mounds) within the project area is already underway. Preliminary results from this two-year study show that fibrous materials feature higher oyster densities, on average, per square meter than other materials but that these oysters tended to be smaller (i.e., higher densities in smaller size classes). The model-based component uses FLOW-3D, a three-dimensional computational fluid dynamic model (CFD), to evaluate material effects on wave transmission and wave effects on the physical stability of structures during common and Category III Hurricane events, respectively. To investigate if wave attenuation improves in different configuration scenarios, models utilize a full factorial design to examine different material types alone and with other materials in three zones: nearshore sill, mid-reef and deep reef. These modeling efforts are still underway. However, models involving material types alone within the mid-reef zone have been completed for common wave and water level conditions. Preliminary wave transmission coefficients calculated from these model runs suggest that rubble rock performs marginally better than other material types (kt = 0.56 vs. 0.61 ≤ 0.66 for fibrous materials and domes).
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2 min Poster Preview
2 min presentation
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Role of nonlinear tide and wave-meanflow interaction in the sediment transport processes along the Old Inlet Breach, Fire Island, NY
Yicheng Huang
Yicheng Huang
Stony Brook University
Mr. Yicheng Huang is a Ph.D. candidate on physical oceanography at the School of Marine and Atmospheric Sciences at Stony Brook University, under the advice of Dr. Robert Wilson and Dr. Henry Bokuniewicz. His research interests are on wave-current interactions and sediment transport in the coastal environment.
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Abstract
Abstract
The Old Inlet Breach was opened by Hurricane Sandy on Fire Island, NY, in 2012. Since then, the tidal current scouring (with speed up to 2.5 m/s at the inlet throat) and wave striking (with the significant wave height of more than 2 m during the storm at the ebb-shoal edge) keep changing the breach’s morphology. A series of monthly aerial photographs show a massive amount of coarse grain sediment (sand with the median grain size of 465 μm according to field measurement) is transported through the breach into Bellport Bay, forming a fast-expanding flood-shoal system (L. W. Foderaro (2013)). This study evaluates the sediment transport and hydrodynamics along the inlet using the Coupled Ocean-Atmospheric-Wave-Sediment Transport model. The sediment transport in the simulation consists of a suspend-load transport part modeled by advection-diffusion equation and a bedload transport part modeled by the semi-empirical treatment from R. L. Soulsby and J. S. Damgaard (2005). The model shows that the direction of tidally averaged sediment transport reverses at both sides of the throat of Old Inlet Breach. On the north side (bay side) of the throat, the tidally averaged sediment transport goes north, while on the other side (ocean side), the tidally averaged sediment transport goes south. By comparing the sediment transport in the modeling scenario with or without the wave-meanflow interaction, it is found that the tidally asymmetric wave stirring effect is causing a decrement of the offshore directed tidally averaged sediment transport on the ebb-shoal, which is consistent with the previous research in the similar environment (G. Dodet et al. 2013). At the vicinity of the inlet throat, when the wave energy is not significant (the significant wave height less than 0.1 m), the tidally averaged sediment transport is also strongly affected by the wave-meanflow interaction. On the ebb-shoal side of the inlet throat, during the storm, the ebb-directed tidally averaged bedload and suspended load transport can be decreased by wave-meanflow interaction by 40% and 60%, respectively. On the flood-shoal side of the inlet throat, during the storm, the flood-directed bedload and suspended load transport through the inlet channel into the back bay can be enhanced by wave-meanflow interaction by 20% and 30%, respectively. Such an effect is majorly contributed by the impact of wave-meanflow interaction on the M2, M4 tidal constituents, and Eulerian meanflow.
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Development of a Mid-Atlantic Surf Hazards Awareness and Research Coordination
Dr Kathleen Fallon
Dr Kathleen Fallon
New York Sea Grant
Dr. Kathleen Fallon is the Coastal Processes and Hazards Specialist with New York Sea Grant. She graduated with a BS in Marine Sciences from Stony Brook University and conducted her graduate research focusing on rip current formation and safety at Florida International University. Currently, in her position she provides technical information about coastal processes and hazards such as flooding and erosion to various stakeholders including researchers, municipal officials, and residents.
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Abstract
Abstract
In 2019, New York Sea Grant (NYSG) and the Mid-Atlantic Regional Association Coastal Ocean Observing System (MARACOOS) collaborated to develop the Surf Hazard Awareness and Research Coordination (SHARC). MARACOOS collects unique ocean data that can be used and improved upon by SHARC in order to increase the understanding and awareness of surf hazards; while NYSG excels at facilitating technical discussions and extending research to appropriate stakeholders. Surf hazards, such as dangerous waves and currents, pose a serious threat to beachgoers; this includes rip currents, which alone kill over 100 people each year at US beaches. The purpose of SHARC is to first increase collaboration and communication between local surf hazard experts and professionals such as researchers, modelers, forecasters, lifesaving personnel, first responders, and municipal decision-makers. Through the network of experts, increased collaboration and communication will lead to better, more localized data collection that will inform forecasting and predictions, in turn increasing beach safety. As professional engagements increase, the ability to better communicate with and educate beachgoers about how to avoid hazards specific to certain beach areas will be greater. The goal of SHARC is to increase capacity and collaboration in order to improve data, and ultimately decrease surf hazard-related incidents and fatalities at the beach. Initially piloted on Long Island, NY, SHARC will be expanded throughout the Mid-Atlantic Region.
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Dredge prioritization and dredged material placement: Optimizing public benefits and beneficial use of dredged material on the Delaware coast
Justin Shawler
Justin Shawler
Delaware Department of Natural Resources and Environmental Control
Justin Shawler is a Coastal Scientist in the Delaware Department of Natural Resources and Environmental Control’s Shoreline and Waterway Management Section where he executes and oversees scientific studies of the state’s beaches and waterways. Justin is also a PhD candidate in coastal geology at the Virginia Institute of Marine Science. His research interests primarily focus on barrier island response to sea-level rise and time-varying sediment fluxes.
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Abstract
Abstract
“Waterway managers around the nation face the two-pronged challenge of limited financial resources and limited dredged material placement options. This is particularly true along the Delaware coast, where the needs for and costs of dredging state-maintained channels are rising, and the availability of traditional upland confined disposal facilities (CDFs) is declining. This project details an effort by the Delaware Department of Natural Resources and Environmental Control’s Shoreline and Waterway Management Section to address this two-fold problem for 35 statewide channels and channel reaches in Delaware with a prioritization tool that integrates shoaling data, dredge material disposal options, and metrics for boater use, safety, and access into a geospatial database.
Use, safety, and access are measured primarily by proxy data (e.g., public boat ramps, marinas, emergency vessel use, etc.) and cross-validated using a stakeholder survey of users (n = 1033) of select channels. Channel shoaling above authorized depths is calculated using a mix of in-house, contractual, and partnered single beam bathymetric survey data. For CDFs, sites historically used by the State’s dredge program for disposal were populated into a GIS polygon shapefile with information on location, ownership, status for use, and past utilization. For beneficial use analysis, a programmatic priority is to focus on publicly owned wetlands as potential sites for ecological uplift. Thus, publicly available shapefiles of state and municipal owned lands were intersected with estuarine vegetated marsh layers to identify candidate marsh sites. Additionally, a 10,000-foot buffer was generated around each channel center line, and the buffer was used to determine marsh area and capacity (cubic yards, assuming a 6-inch lift) proximal to each channel.
The results of these analyses reveal 1) the highest use channels – and thus those that often rank as higher priorities for dredging – lack abundant publicly owned marshes within a reasonable pumping distance, 2) a singular focus on beneficial use of sediment for ecological uplift may place competing demands on marsh sites in the same way we have to balance competing demands on limited CDF sites, and 3) future planning must consider a variety of disposal options, including restoration of private marshes, real estate purchases of new CDF sites, and identification of other habitat creation/restoration opportunities (e.g., island creation, beach nourishment, and living shoreline construction). To address the latter, planning-level sediment core data will be collected to refine the best uses of sediment from each channel based on sediment type. Additionally, future work involves collaborating with wetlands managers to identify saltmarsh sites that will ecologically benefit the most from restoration using dredged material, such as sites with a history of sudden wetland dieback and/or extensive ponding. Finally, the project emphasizes the need for comprehensive waterway management and regional sediment management rather than ad hoc, project-by-project placement of dredged sediment. “
Use, safety, and access are measured primarily by proxy data (e.g., public boat ramps, marinas, emergency vessel use, etc.) and cross-validated using a stakeholder survey of users (n = 1033) of select channels. Channel shoaling above authorized depths is calculated using a mix of in-house, contractual, and partnered single beam bathymetric survey data. For CDFs, sites historically used by the State’s dredge program for disposal were populated into a GIS polygon shapefile with information on location, ownership, status for use, and past utilization. For beneficial use analysis, a programmatic priority is to focus on publicly owned wetlands as potential sites for ecological uplift. Thus, publicly available shapefiles of state and municipal owned lands were intersected with estuarine vegetated marsh layers to identify candidate marsh sites. Additionally, a 10,000-foot buffer was generated around each channel center line, and the buffer was used to determine marsh area and capacity (cubic yards, assuming a 6-inch lift) proximal to each channel.
The results of these analyses reveal 1) the highest use channels – and thus those that often rank as higher priorities for dredging – lack abundant publicly owned marshes within a reasonable pumping distance, 2) a singular focus on beneficial use of sediment for ecological uplift may place competing demands on marsh sites in the same way we have to balance competing demands on limited CDF sites, and 3) future planning must consider a variety of disposal options, including restoration of private marshes, real estate purchases of new CDF sites, and identification of other habitat creation/restoration opportunities (e.g., island creation, beach nourishment, and living shoreline construction). To address the latter, planning-level sediment core data will be collected to refine the best uses of sediment from each channel based on sediment type. Additionally, future work involves collaborating with wetlands managers to identify saltmarsh sites that will ecologically benefit the most from restoration using dredged material, such as sites with a history of sudden wetland dieback and/or extensive ponding. Finally, the project emphasizes the need for comprehensive waterway management and regional sediment management rather than ad hoc, project-by-project placement of dredged sediment. “
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*Virtual Participant
Using XBeach to evaluate dune versus marsh restoration end member fill templates for enhanced barrier island resiliency: Chandeleur Islands, Gulf of Mexico
Diana Di Leonardo
Diana Di Leonardo
The Water Institute of the Gulf
Diana Di Leonardo is a Research Scientist with The Water Institute of the Gulf in the Applied Geosciences Group. She has eight years of experience researching and working on the Louisiana coast. She currently works on coastal projects involving field data as well as models.
Prior to arriving in Louisiana, Di Leonardo explored the Oregon and Washington coasts for her Master’s research. She participated in hundreds of nearshore survey transects to track sandbar migration and demarcate flood maps. These rocky coast environments provide a fascinating contrast to Louisiana’s marshes.
She earned her BA in Geosciences from Hamilton College and her MS in Geology from Oregon State University.
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Abstract
Abstract
“The Chandeleur Islands in Louisiana comprise Breton National Wildlife Refuge and provide widespread ecosystem services to the region. The 80-km barrier chain attenuates wave energy and regulates salinities in the Chandeleur and Mississippi Sounds, protects landward marshes and oyster reefs, and provides key habitat to species such as sea turtles, pelicans, and shorebirds. Seagrass beds in the lee of the islands are an important part of this ecosystem, providing shelter and food for hundreds of species. This highly valuable system is in a state of rapid decline due to sand loss from the system to deep water sinks. The original sand source that led to island development has been exhausted, and there is no modern source of sediment beyond what is reworked from the island itself. It is projected that these islands will be completely converted to submerged shoals within a few decades. In response, there are efforts underway to develop restoration and long-term management strategies. The Chandeleur Islands offer a unique ecosystem restoration opportunity because they are pristine; human infrastructure is absent due to a Federal Wilderness designation. Beach nourishment often focuses on rebuilding the beach and enhancing dune height to provide protection to infrastructure and communities which is not a priority in this case. The primary interest in restoration is maximizing sand retention within the system, as it responds to hurricane impacts and rapid relative sea level rise and enhancing ecosystem services the islands provide over the long term. Here, we employ numerical models to test two endmember restoration strategies that aim to maximize island life span by reintroducing sand that has been lost from the system: a fill template with continuous dune and one with no dune but extensive backbarrier marsh platforms.
An XBeach numerical model was used to investigate sediment transport dynamics under storm conditions for the existing conditions at the Chandeleur Islands and to determine how sediment placement design may best provide ecosystem benefits in the context of storm response and resiliency. Four storm conditions (weak, intermediate, strong, and extreme) were run on three island conditions (FWOA, dune endmember restoration, marsh endmember restoration). A high dune favors collision regime impacts and transport of sand from the island toward the surf zone for a longer duration during all storms, resulting in a decrease in subaerial sediment volume post-storm. In contrast, the marsh end member restoration enhances sand overwash from the island to the backbarrier marsh platform resulting in an increase in subaerial sediment volume. Our results show that the marsh end member restoration template maximizes sediment capture enabled by inundation and overwash processes, retaining sand within the system while building up a platform for deposition of that material during storms.”
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Modeling and mapping of urban flood prone areas with proposed flood control structures
Dr Chang Liu
Dr Chang Liu
University of Connecticut
Dr. Chang Liu is Research Associate at Connecticut Institute for Resilience & Climate Adaptation (CIRCA). He received his Ph.D. and M.S. in Marine Science from University of Massachusetts Dartmouth. Chang’s work at CIRCA focuses on storm surge and wave modeling in coastal Connecticut. His research interests include ocean and marine ecosystem modeling with an emphasis on computational and statistical approaches.
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Abstract
Abstract
New Haven area is one of the largest flood prone areas in the Connecticut coastal line. Carefully placed flood control structures and raised roadways could protect Connecticut’s vulnerable infrastructure from severe flooding. In this study, using the weir formula of hydrodynamics model ADCIRC, we show the different impacts on the community of a flood event under different design scenarios of proposed flood control structures. Using GIS mapping tools, detailed building and infrastructure flooding information are visualized and summarized. Results show that the implementation of flood control structures around the Tweed New Haven Airport is expected to reduce up to 76% in flooded buildings and 20% in flooded roads during a simulated flood event. Proposed raised roadways are also expected to reduce flooding in West Haven coastal communities. This analysis could be applied to other Connecticut municipalities and benefit the climate resilience planning of Connecticut.
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*Virtual Participant
Rapid-response observations on barrier islands along Cape Fear, North Carolina during Hurricane Isaias
Dr Ryan Mieras
Dr Ryan Mieras
University of North Carolina Wilmington
Dr. Mieras is an Assistant Professor of Coastal Engineering at the University of North Carolina Wilmington. His research encompasses sediment transport and hydrodynamic processes in nearshore and wetland environments, via field and laboratory studies, in order to improve predictions of coastal geomorphic change. Overall, Dr. Mieras’ Coastal Sediments and Hydrodynamics Laboratory (CSHL) conducts basic and applied research to improve our understanding of the physical processes driving coastal flooding and geomorphology in a changing climate, leading to more effective coastal protection strategies against increasingly frequent intense storms and rising sea levels.
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Abstract
Abstract
Hurricane Isaias struck the Cape Fear Region of North Carolina around 2300 EDT on 3 August 2020, making landfall at Ocean Isle Beach as a Category 1 storm with peak wind speeds of 80 mph. An array of nearshore Sofar Spotter wave buoys captured the wave field at two beaches off the coasts of Bald Head Island (south-facing and east-facing beaches) and Masonboro Island. Local variations in significant wave height and peak wave direction were observed along the Lower Cape Fear Region, due to large shoal features impacting the regional wave climate. A cross-shore transect of five pressure sensors was installed at the north end of Masonboro Island 2.5 days prior to landfall to measure storm surge, wave runup, and variation of gravity/infragravity wave energy across the barrier island. The three fast-sampling wave gauges along the backshore became buried before Hurricane Isaias peak storm surge, and the two gauges on and behind the dune were never inundated. A low-cost (< $250) Storm Surge Observation Camera (SSOC) prototype captured storm surge and coastal erosion at Kure Beach, in conjunction with pre- and post-storm RTK GPS beach profile surveys. Kure Beach experienced more than 1.0 m of vertical erosion of the berm, while Masonboro Island experienced around 0.1 m of accretion across the backshore, despite nearly identical wave and wind forcing conditions at the two beaches separated by ~20 km. Pre-storm berm height and width (higher and wider at Kure Beach), as well as foreshore slope (steeper, 1:9, at Kure Beach), are likely factors influencing significant erosion at Kure Beach, while slight accretion was observed at Masonboro Island.
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Supplementing natural accretion processes in the Louisiana coastal zone with dredged sediment
Chris McLindon
Chris McLindon
McLindon Geosciences, LLC
Chris McLindon worked as a geologist in the oil and gas industry for 40 years. Chris has worked for the past six years with professors and students at Tulane, UL-Lafayette and UNO to study the relationships between subsurface geology and coastal processes. In 2017 He was named as a director of the Louisiana Coastal Geohazards Atlas by Dr. Charles Groat of the Louisiana Geological Survey. In 2017 Chris was also the recipient of the Gulf Coast Association of Geological Societies Statesmanship Award for his work in this area.
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Abstract
Abstract
Data from the Louisiana Coastwide Reference Monitoring System (CRMS) is indicating that a robust supply of sediment is being delivered to the saline and brackish marshes of the Terrebonne, Barataria and Breton estuaries by tidal exchange. A majority of the CRMS stations in the study area are measuring rates of sediment accretion that exceed the combined rates of subsidence and sea level rise, and 70% of the stations in the delta region are measuring positive elevation trajectories relative to a fixed rod at the site.
A detailed examination of a stable marsh platform in the Barataria estuary indicates that the source of the sediment is a combination of edge erosion of the emergent marsh and subaqueous erosion of recently submerged sediment along the perimeter of the platform. CRMS imagery data indicates that the magnitude of loss by edge erosion is partial offset be deposition within and infilling of ponds in the interior platform. This configuration suggests the edge erosion could be partially mitigated and the depositional process could be supplemented by placing berms of dredge sediment along the edges of the marsh platform. The berms would wash away over time, but they would serve to protect the platform edge from wave erosion and a portion of the sediment would be carried onto the platform by tidal exchange. The process could be repeated after the berms wash away. A proposed source of sediment would be material dredged from the Mississippi River channel and transported to the project site by barge. This process has the capability to offer long-term sustainability of these marshes.
A detailed examination of a stable marsh platform in the Barataria estuary indicates that the source of the sediment is a combination of edge erosion of the emergent marsh and subaqueous erosion of recently submerged sediment along the perimeter of the platform. CRMS imagery data indicates that the magnitude of loss by edge erosion is partial offset be deposition within and infilling of ponds in the interior platform. This configuration suggests the edge erosion could be partially mitigated and the depositional process could be supplemented by placing berms of dredge sediment along the edges of the marsh platform. The berms would wash away over time, but they would serve to protect the platform edge from wave erosion and a portion of the sediment would be carried onto the platform by tidal exchange. The process could be repeated after the berms wash away. A proposed source of sediment would be material dredged from the Mississippi River channel and transported to the project site by barge. This process has the capability to offer long-term sustainability of these marshes.
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Living Shoreline Creation at the Katherine Hepburn Estate, Fenwick CT
Stephen Lecco
Stephen Lecco
GZA GeoEnvironmental
Stephen Lecco, AICP, CEP is an Associate Principal with GZA GeoEnvironmental, Inc. He is the Ecological Services Technical Practice Lead for GZA’s southern New England and Mid-Atlantic regions, with expertise in coastal development, restoration and permitting. Mr. Lecco has been providing such services for government, private and conservation organizations for over 34 years. He holds a B.A. in Geography/Urban & Regional Planning and an M.S. in Environmental Science.
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Abstract
Abstract
“GZA GeoEnvironmental, Inc. (GZA) was retained by the Borough of Fenwick in Old Saybrook, CT to develop plans to protect approximately 450 linear feet of shoreline along Long Island sound adjacent to the former Katherine Hepburn Estate. The site is currently owned by the Lynde Point Land Trust.
Shoreline change and erosion have been on-going issues along this barrier spit. The Borough has expended significant effort and cost to stabilize the shoreline during the last 10 to 15 years; however, erosion continues and there is concern that future storm events may exacerbate the breach in the barrier spit that occurred during the winter of 2019. This breach could have negative consequences for both improved property in the area and the recently restored tidal marsh and creek located inland of the barrier spit as well as a tidal pond that connects to the creek.
In an attempt to stabilize the barrier spit and dune, the dune was reconstructed in 2007 and reinforced using sand-filled tubes and imported sand to construct a reinforced dune. The reinforced dune was planted in 2008 with American beach grass and switch grass, which became well-established; however, Hurricane Irene (2011) and subsequently Superstorm Sandy (2012) completely eroded the reinforced dune, destroyed the sand tubes and deposited overwash sand in the backwater marsh and creek.
During April of 2017, The Borough contacted the Connecticut Department of Energy and Environmental Protection (DEEP), which suggested a sustainable and innovative “Living Shoreline” approach to dune and marsh protection. The Living Shoreline approach suggested by DEEP included dune restoration, beach sand placement, coir logs, marsh restoration, stone sills and wave attenuation structures.
During 2017, GZA assisted the Borough with a successful grant application with the Connecticut Institute for Resilience & Climate Adaptation (CIRCA) to assist with funding for final engineering and design. As part of the grant, the project was used as a case study for constructing a Living Shoreline in Connecticut.
During the winter of 2019, storm activity led to a breach in the dune with overwash material filling the adjacent Crab Creek so the DEEP’s Wetland Restoration Unit responded by providing a temporary hydraulic connection from the creek to the tidal pond.
GZA prepared plans and permit documents and the project was approved by local, state and federal agencies in the summer of 2020. Robust numerical wave modeling was also conducted to inform the design. Construction began in September 2020 and was completed in June 2021. During construction, a series of storms impacted the constructed marsh so adaptive measures were taken to modify the sill and dune design in close coordination with the regulatory agencies. Construction was completed in June 2021 and will be monitored as required by the permits.
Senator Chris Murphy, co-writer of The Living Shorelines Act, and Chairman of the Senate Appropriations Subcommittee on Homeland Security, invited GZA to share lessons learned with state and local government officials and environmental advocates. Senator Murphy intends to emphasize FEMA invest more funds in preparing Connecticut’s shoreline for natural disasters.”
Shoreline change and erosion have been on-going issues along this barrier spit. The Borough has expended significant effort and cost to stabilize the shoreline during the last 10 to 15 years; however, erosion continues and there is concern that future storm events may exacerbate the breach in the barrier spit that occurred during the winter of 2019. This breach could have negative consequences for both improved property in the area and the recently restored tidal marsh and creek located inland of the barrier spit as well as a tidal pond that connects to the creek.
In an attempt to stabilize the barrier spit and dune, the dune was reconstructed in 2007 and reinforced using sand-filled tubes and imported sand to construct a reinforced dune. The reinforced dune was planted in 2008 with American beach grass and switch grass, which became well-established; however, Hurricane Irene (2011) and subsequently Superstorm Sandy (2012) completely eroded the reinforced dune, destroyed the sand tubes and deposited overwash sand in the backwater marsh and creek.
During April of 2017, The Borough contacted the Connecticut Department of Energy and Environmental Protection (DEEP), which suggested a sustainable and innovative “Living Shoreline” approach to dune and marsh protection. The Living Shoreline approach suggested by DEEP included dune restoration, beach sand placement, coir logs, marsh restoration, stone sills and wave attenuation structures.
During 2017, GZA assisted the Borough with a successful grant application with the Connecticut Institute for Resilience & Climate Adaptation (CIRCA) to assist with funding for final engineering and design. As part of the grant, the project was used as a case study for constructing a Living Shoreline in Connecticut.
During the winter of 2019, storm activity led to a breach in the dune with overwash material filling the adjacent Crab Creek so the DEEP’s Wetland Restoration Unit responded by providing a temporary hydraulic connection from the creek to the tidal pond.
GZA prepared plans and permit documents and the project was approved by local, state and federal agencies in the summer of 2020. Robust numerical wave modeling was also conducted to inform the design. Construction began in September 2020 and was completed in June 2021. During construction, a series of storms impacted the constructed marsh so adaptive measures were taken to modify the sill and dune design in close coordination with the regulatory agencies. Construction was completed in June 2021 and will be monitored as required by the permits.
Senator Chris Murphy, co-writer of The Living Shorelines Act, and Chairman of the Senate Appropriations Subcommittee on Homeland Security, invited GZA to share lessons learned with state and local government officials and environmental advocates. Senator Murphy intends to emphasize FEMA invest more funds in preparing Connecticut’s shoreline for natural disasters.”
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Development of Subdomain Sizing Guidelines for the Subdomain Modeling Extension for ADCIRC
Dr Fatima Bukhari
Dr Fatima Bukhari
US Army Corps of Engineers, ERDC
Dr. Bukhari earned her Ph.D. in Civil Engineering from North Carolina State University after completion of her B.S. from the University of Alaska Anchorage and M.S. from State University of New York at Buffalo (Both in Civil Engineering). She focuses on studies that involve evaluating engineering structures for their impact to increasing coastal resilience and reducing risk from storm damages using numerical storm surge models such as ADCIRC. She serves a Research Civil Engineer for the US Army Engineer Research & Development Center – Coastal & Hydraulics Laboratory.
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Abstract
Abstract
United States Army Corps of Engineers (USACE) districts are routinely and actively engaged in coastal flood hazard studies, evaluating engineering structures for their impact to increasing coastal resilience and reducing risk from storm damages. Modeling efforts for these studies often rely on the Coastal Storm Modeling System (CSTORM-MS) (Massey et al. 2012, Cialone et al. 2015) to simulate large-scale domains with high-resolution accuracy around the proposed project areas. Incorporated as a part of CSTORM-MS is the well-validated, highly accurate circulation and surge model known as ADCIRC (Luettich et al. 1992, Westerink et al. 2008). Proper evaluation of designs for flood risk reduction projects under storm conditions; require large ADCIRC model domains (Blain et al., 1994) to represent accurately large-scale hydrodynamic effects such as storm forerunner water levels (Kerr et al., 2013).
While capable of producing highly accurate simulations, substantive demands on computational resources are characteristic of ADCIRC domains. This demand on computational resources occurs due to the scale and complexity of coastal processes and ocean physics, and the evaluation of a variety of engineering design scenarios, which involves additional refinements to already highly resolved large-scale domains. The burden on computational resources is further exacerbated with the number of storm suites and water levels required for evaluation of each design scenario. These issues often result in a tradeoff between number of storm/water levels evaluated with the number of design scenarios being evaluated.
To help address these concerns, a promising new capability known as subdomain modeling (SM) (Baugh et al., 2015) was recently incorporated into ADCIRC. SM allows local changes in subdomains to be accommodated with less computational effort than required by running a full domain with equivalent changes. Since SM operates on smaller domains using specialized boundary conditions obtained from full domains, subdomain simulations require a fraction of the computational cost and are relatively easy to setup. In addition, SM allows for fuller evaluation of designs and forcing conditions, while producing the same results that would be obtained by equivalent full simulations, so long as hydrodynamic effects from any changes made to a subdomain do not propagate to the boundaries.
While SM has been shown to be mathematically equivalent to full domain solutions through informal proofs (Baugh et al., 2015) and prior research exploring the performance of SM both for its computational benefit and solution quality as compared to full domain simulations and their solutions, practical guidance on appropriate sizing and location of the SM domains needs to be developed. The work presented herein describes the efforts to develop conservative rule of thumb estimates to SM boundary placements, based on the several factors, including types of changes proposed within a SM domain (e.g. addition of a wetland or a breakwater), the size of the proposed changes, the local geometry where the changes are to be made, and the forcing conditions being applied to ADCIRC (e.g. tidal only vs hurricane storm surge forcing). Examples from two USACE projects will be given and early findings relative to SM domain sizing will be presented.
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HIGH SCHOOL STEM ENGAGEMENT USING PORTABLE WAVE FLUMES
Dr Jack Puleo
Dr Jack Puleo
University of Delaware
Jack Puleo is a Professor and Chair in the Department of Civil and Environmental Engineering and a core faculty member of the Center for Applied Coastal Research (CACR) at the University of Delaware (UD). He completed the Ph.D. from the University of Florida in 2004. He was a Fulbright Scholar and visiting Professor at Plymouth University in 2011-2012 and is presently an intermittent faculty member at NRL. Puleo conducts research on small-scale hydrodynamic and sediment transport processes in coastal environments. His research involves designing sensor networks, developing new sensors, and conducting rapid-response deployments to quantify intra-storm processes.
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Abstract
Abstract
There is a trend in the USA for increased STEM content in the HS curriculum. Unfortunately, only roughly 5% of all Bachelor’s degrees in the USA are engineering related. In addition, only 26% and 22% of USA 12th grade students reach proficiency in mathematics and science respectively. Efforts to combat these low numbers include aspects such as Project Lead the Way (with its partnership with the ERB) and in developing National Science Education Standards (NSES) and Next Generation Science Standards (NGSS). NSES and NGSS focus on inquiry-based learning, engineering design, and building science-related skills. Full inquiry (math is essential in inquiry) requires formulating a question, completing an investigation, using data to answer the question, and presenting the results to others.
We present engaging, hands-on activities related to coastal dynamics that enable adherence to these NSES and NGSS standards. A portable wave flume and educational modules have been designed. The flume consists of two 2.44 m sections of optical-quality acrylic that are joined in the center to form a 4.88 m long flume. The flume is 25 cm tall and 12 cm wide. A flap-type wave paddle is hinged at the offshore end of the flume and attached using a linkage arm to a DC motor with wheel. A variable speed controller is used to alter the speed of paddle motion and hence wave frequency. Acetal beads are used as a sediment surrogate to create a “natural” beach that evolves quickly. A local cross-shore coordinate system along the bottom of the flume is defined for positioning. Morphological changes can be quantified pre- and post-wave conditions using pin striping tape or grease pen and a ruler.
Thirteen wave flume systems have been delivered to high schools along the east coast of the United States ranging from Sandy Hook, NJ to Naples, FL. Thirteen wave flume modules have been designed around topics including wave parameters, tsunami, sea level rise, beach erosion, and beach nourishment to name a few. Students are provided guidance to conduct the modules/exercises but often presented with open-ended questions for inquiry. Google forms and pre- and post-module worksheets are provided to assess learning outcomes. Preliminary assessment data will be presented.
We present engaging, hands-on activities related to coastal dynamics that enable adherence to these NSES and NGSS standards. A portable wave flume and educational modules have been designed. The flume consists of two 2.44 m sections of optical-quality acrylic that are joined in the center to form a 4.88 m long flume. The flume is 25 cm tall and 12 cm wide. A flap-type wave paddle is hinged at the offshore end of the flume and attached using a linkage arm to a DC motor with wheel. A variable speed controller is used to alter the speed of paddle motion and hence wave frequency. Acetal beads are used as a sediment surrogate to create a “natural” beach that evolves quickly. A local cross-shore coordinate system along the bottom of the flume is defined for positioning. Morphological changes can be quantified pre- and post-wave conditions using pin striping tape or grease pen and a ruler.
Thirteen wave flume systems have been delivered to high schools along the east coast of the United States ranging from Sandy Hook, NJ to Naples, FL. Thirteen wave flume modules have been designed around topics including wave parameters, tsunami, sea level rise, beach erosion, and beach nourishment to name a few. Students are provided guidance to conduct the modules/exercises but often presented with open-ended questions for inquiry. Google forms and pre- and post-module worksheets are provided to assess learning outcomes. Preliminary assessment data will be presented.
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Evaluation of Mechanical Beach Cleaning on Infaunal Macroinvertebrates in Hawai‘i
Ruby Pap
Ruby Pap
Hawai`i Sea Grant
Ruby Pap is a Coastal Land Use Extension Specialist with Hawai`i Sea Grant based on the Island of Kaua`i. She works as a liaison between researchers and county government, non-government organizations, and island residents to help ensure coastal science is usable and applicable to local needs.
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Abstract
Abstract
Hawai`i is renowned for the beauty of its beaches. Unfortunately, these beaches are experiencing increasing marine debris including small, persistent, man-made debris that is difficult to clean by hand. On some island beaches mechanized cleaning is used to remove marine debris and some community pressure exists to expand the adoption of mechanized grooming. A few studies have shown such grooming alters beaches and the associated ecosystem services they provide, largely via impacts to sand-dwelling organisms. No studies have been conducted in Hawai‘i on the impact of mechanized marine debris removal on unique island beaches. Here, we evaluate mechanized marine debris removal on Hawai`i’s upper intertidal by examining macroinvertebrates on beaches with and without mechanized maintenance. Results will apprise stakeholders in the Hawaiian Islands on beach management and marine debris removal as well as inform governance and maintenance of beach ecosystems in the greater insular Pacific.
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STRUCTURE POROSITY ENHANCES SEDIMENTATION BEHIND SHORELINE PROTECTION ALTERNATIVES
Tommy McGinnis
Tommy McGinnis
Coastal Protection and Restoration Authority – Lafayette Regional Office
Mr. McGinnis is a wetland ecologist with 12 years of coastal wetland research and 14 years of restoration monitoring experience. He has experience in a variety of coastal wetland types from marshes to mangroves and has been the monitoring manager for restoration projects involving a variety of restoration techniques.
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Abstract
Abstract
As shoreline erosion pushes inland, the typical beach/berm setting suited for high exposure to wind and waves thins and disappears, thus exposing the more fragile marsh edge to hydrologic forces. Shoreline protection becomes more complicated as the former marsh platform becomes the substrate upon which shoreline protection features are placed. This former marsh platform often has higher organic matter content and thick, soft clays which have a low weight-bearing capacity. The result is that the high-density rock rip-rap breakwaters traditionally used for shoreline protection sink into the weaker soils. As part of a CWPPRA demonstration project, LA-0016 Non-rock Alternatives to Shoreline Protection, we evaluated four manufactured shoreline protection structures in a highly erosive area with low weight-bearing capacity along northwestern Vermilion Bay. Two structures allowed water to pass though (porous), Wave Attenuation Devices (WADs) and Wave Screen System (WSS), while two structures were barriers, Buoyancy Compensated Erosion Control Modular System (BCECMS) and Ecosystem Units (ECUs). We monitored structure stability, wave breaking performance (attenuation), shoreline movement, and soil volume change (determined from repeated elevation surveys) at and behind each structure and an unprotected reference area. While all of the structures attenuated waves by at least 65% and reduced shoreline erosion by at least 85%, porous structures (WSS and WADs) had less erosion than structures that acted as wave barriers ( ESUs and BCECMS). The more porous structures actually gained sediment volume between the structure and the shoreline, and the WSS, which was suspended a couple feet above the bay bottom, gained soil volume on the bayside of the structure. A coast-wide synthesis of 12 shoreline protection alternatives (LSU Coastal Engineering Master’s Thesis by Hunter Shows) revealed a positive relationship between structure porosity (potential for water to pass through the structure) up to 35% and soil volume change. Structure porosity was determined from design drawings by Shows, and soil volume change data was provided by CPRA project monitoring.
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Trail Guide for Practitioners: A Virtual, Interactive, and Informative tool for the Marsh Equilibrium Model (MEM)
Abigail Eilar
Abigail Eilar
US Army Corps of Engineers, ERDC
Abigail is an ORISE Fellow for USACE at the Engineer Research Development Center (ERDC) in Vicksburg, MS. As a research scientist, she is working on a variety of projects covering coastal and marsh restoration, modeling, and beneficial use of dredge material. Abigail received a B.S. in Biological Sciences from Mississippi State University and her M.S. in Marine Biology from Northeastern University where she developed a passion for coastal and marsh restoration and how to integrate social sciences in addition. As part of the Northeastern program, Abigail also has scientific diving experience in the Atlantic, Caribbean, and Pacific oceans.
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Abstract
Abstract
As risks to marsh survival increase, knowledge and tools to protect marshes are important to maintaining their economic and ecological benefits. The Marsh Equilibrium Model (MEM) aids in understanding marsh processes to inform restoration and management decisions and solutions to achieve the USACE goal of creating solutions to environmental challenges and promoting resilient habitats. The Marsh Equilibrium Model (MEM) is a tool that helps predict salt marsh sustainability by using variables that drive salt marsh function (e.g. sea level rise, biomass productivity, and accretion rates to understand how anticipated environmental and anthropogenic changes will impact salt marsh elevation. MEM can be used to determine how marshes will respond to short and long-term reduced sediment loading to better inform where and when sediment addition would be the most beneficial.
While MEM was developed as a research tool, it can be applied in practice to identify and prioritize restoration activities. The MEM was utilized in a study of Mobile Harbor, AL to understand the impact of the beneficial use of dredge material (BUDM) for site restoration and informed the best practice for thin-layer placement. The model helped determine the volume and height of placed material based on biophysical constraints and the frequency that placement events need to occur based on sea-level rise estimates. Although MEM was utilized in this project, further documentation and tutorials are required for MEM to be fully utilized by practitioners.
With this goal in mind, the MEM Trail Guide was created to describe the inputs and outputs used in MEM to parameterize the model, how they are measured, and the role they play in the marsh dynamics. The Trail Guide may aid in the planning process of restoration by allowing for predictions of impacts of newly deposited material and how newly restored marshes may respond to rising sea levels. The interactive form of the Trail Guide allows users access to a simplified version of MEM to better understand the inputs/outputs in action and reflect how marsh conditions will subsequently change. Overall the development of the MEM Trail Guide offers a user-friendly virtual interface for practitioners to use in the planning period of a restoration project without the need for someone experienced to run the MEM. For future BUDM projects, the Trail Guide may allow project managers to determine which marsh zones require sediment nourishment and at what amount and frequency placement will be necessary.
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Offshore Sand Source Investigations for Counties in Southeast and Southwest Florida.
Natalie Lamb
Natalie Lamb
Taylor Engineering, Inc.
Natalie Lamb serves as a Geologist at Taylor Engineering. Ms. Lamb assists in the company’s Coastal & Marine Geosciences Lab, specializing in sediment quality evaluation for dredging, shore protection, and sand source investigation projects throughout the state.
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Abstract
Abstract
he United States Army Corps of Engineers (USACE) South Atlantic Division (SAD) consists of the coastal regions of Mississippi, Alabama, Florida, Georgia, South Carolina, and North Carolina. Storms and rising sea level threaten the region’s coastal zones, thus the USACE initiated a multiple part project to enhance coastal resiliency within the division.
Part 1 of this project was a desktop study to quantify sand needs and available sand sources for each county within the SAD over the next 50 years. The project team determined the sand needs based on the nourishment history or recorded erosion rates for all federal and non-federal beach projects. Identified sand sources included offshore, upland, and Regional Sediment Management (RSM) beneficial use sources, such as navigation channels or inlet complexes. The project team compared the sand needs to the available sand sources for each county in the study, calculating the sand balance of each.
Based on the sand balance results of the Part 1 study, the USACE Jacksonville District identified four counties in southeast and southwest Florida for further investigation– Broward, Miami-Dade, Sarasota, and Manatee. USACE chose these counties due to lack of sufficient long-term sand sources currently identified. USACE tasked Taylor Engineering with the collection and analysis of sediment data for these counties, including geophysical surveys and vibracore samples. The project team reviewed preexisting geophysical data and identified new offshore sites for investigation. Before collecting vibracore samples, the team conducted geophysical surveys (multi-beam, sub-bottom, side scan, and magnetometer) to determine which areas had the best potential for beach quality sand deposits and appeared to have sand deposits of reasonable thickness for dredging activities. The team collected 120 vibracores from 75 investigation areas throughout the four counties.
The cores arrived at Taylor Engineering’s Coastal & Marine Geosciences Laboratory in Jacksonville, FL where Taylor’s geologists split, logged, and photographed them. USACE chose samples based on initial draft logs provided by Taylor Engineering, who then analyzed the selected samples for gradation, carbonate content, visual shell, and moist/dry Munsell color. Taylor Engineering deemed core layers as compatible or not compatible based on the beach nourishment sediment criteria for each county. The results showed a total of 54 investigation areas contained beach compatible sediment—of these 54 areas only 36 were volume-contributing based on sediment thickness. The definition of compatible sediments for this study included state and county sand attributes and at least five feet of sediment thickness to align with the industry-standard dredgeable minimum, with an included two-foot dredge buffer (a total of five feet of sand depth). Once compatible layers were identified, Taylor Engineering calculated potential volumes of available sand for each volume-contributing investigation area. The study identified approximately 39 million cubic yards of potential sand across all four counties, with the largest sand deposits found in Manatee County. Further investigations are necessary to better define and permit these investigation areas.
This poster is most applicable for USACE staff, state agencies, staff of local municipalities, local and regional planners, and private industry professionals. The poster will provide an overview of the geophysical and geotechnical sand search results, as well as where new sand deposits in southeast and southwest Florida merit more detailed investigation.
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Southeast Coastal Communities Water Level Observing System
Dr Nicole Elko
Dr Nicole Elko
American Shore and Beach Preservation Association
Nicole Elko, Ph.D., is the Science Director for the American Shore and Beach Preservation Association (ASBPA), Executive Director of the South Carolina Beach Advocates, an Executive Director of the U.S. Coastal Research Program (USCRP), and President of Elko Coastal Consulting based in Folly Beach, SC. She serves as a member of the NOAA’s Hydrographic Services Review Panel (HSRP), and is one of the three civilian members of the U.S. Army Corps’ Coastal Engineering Research Board (CERB).
Dr. Elko has over 20 years of experience managing or assisting with coastal preservation projects along the U.S. Southeast and Gulf coasts. Dr. Elko received her Ph.D. (Geology) from the University of South Florida after working with the USGS Coastal Marine Geology Program, St. Petersburg, and while serving as the coastal coordinator for Pinellas County, FL.
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Abstract
Abstract
The Southeast Coastal Communities Water Level Observing System involves the installation of low-cost water-level sensors that wirelessly telemeter real-time, hyper-local data and tidal predictions to coastal managers’ cell phones through a user-friendly app. The project engages local managers to ensure the placement of the sensors, the data and prediction tools, and usability of the app fit the localized needs of up to 40 communities. The goal of the project is to help coastal managers manage community flooding. For example, by sending notifications when flooding is predicted to reach user-specified thresholds. So far, 15 sensors have been installed throughout North and South Carolina.
The system began as a pilot effort with the South Carolina Beach Advocates. In 2021, the American Shore and Beach Preservation Association received funding from the Southeast Coastal and Ocean Observing Regional Association to expand the network into Florida, North Carolina and throughout the Southeast US.
Project specifics: Most communities are opting to install sensors on the backbay, rather than the beachfront, to target flooding hotspots. Costs are significantly reduced to $500 per sensor thanks to the support of the funding agencies. Communities are required to install the sensors, participate in quarterly project meetings, and obtain any local/state permissions (e.g., permission from a community association to install on private dock) or permits (e.g., DOT encroachment permit to install on state bridge). This is a user-inspired project, so during quarterly progress meetings, communities share installation lessons learned, data requirements, product development, and visualization needs; review the prediction and visualization products developed during the project; share user needs and desired data delivery/visualizations, determine flooding thresholds; and communicate resilience and adaptation planning needs related to coastal flooding that the project can help to address.
The system began as a pilot effort with the South Carolina Beach Advocates. In 2021, the American Shore and Beach Preservation Association received funding from the Southeast Coastal and Ocean Observing Regional Association to expand the network into Florida, North Carolina and throughout the Southeast US.
Project specifics: Most communities are opting to install sensors on the backbay, rather than the beachfront, to target flooding hotspots. Costs are significantly reduced to $500 per sensor thanks to the support of the funding agencies. Communities are required to install the sensors, participate in quarterly project meetings, and obtain any local/state permissions (e.g., permission from a community association to install on private dock) or permits (e.g., DOT encroachment permit to install on state bridge). This is a user-inspired project, so during quarterly progress meetings, communities share installation lessons learned, data requirements, product development, and visualization needs; review the prediction and visualization products developed during the project; share user needs and desired data delivery/visualizations, determine flooding thresholds; and communicate resilience and adaptation planning needs related to coastal flooding that the project can help to address.
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DualSPHysics as a tool for simulating swash zone dynamics under the influence of a double dam break
Dr Manoj Kumar Gangadharan
Dr Manoj Kumar Gangadharan
University of Delaware
Dr. Gangadharan, Manoj Kumar is a postdoctoral researcher at the Center for Applied Coastal Research, University of Delaware, Newark. He received his MS and Ph.D. dual degree in Ocean Engineering from the Indian Institute of Technology Madras, India, for his thesis on “development of a hybrid numerical model for simulating wave structure interaction.” His research interest includes wave structure interaction, extreme waves, hybrid numerical models, computational fluid dynamics, and environmental flows in general.
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Abstract
Abstract
DualSPHysics is an accelerated version of the smooth particle hydrodynamics (SPH) code. The DualSPHysics code originates from SPHysics, which is an open-source SPH model developed by researchers at Johns Hopkins University (US), the University of Vigo (Spain), the University of Manchester (UK), and the University of Rome, La Sapienza. One of the model’s advantages is the ability to exploit the GPU for accelerating the computation, making simulations accessible to desktop computer users.
The capabilities and limitations of the model in simulating swash zone dynamics are investigated in this study. A near prototype, high-energy wave-breaking process is achieved using a double dam break setup. The flume consists of two reservoirs with separate gates that can be operated simultaneously or at specific intervals. Variations in the gate opening intervals and resting water level front of the first gate yield different bore configurations and wave-wave interactions. Different combinations of gate opening intervals were tested. The water surface elevation, pressure gradients at the toe of the beach slope, and runup are compared against the experiment data. The model effectiveness and some of the inherent challenges associated with the Dual SPHysiscs model are also highlighted. The presented work is a part of a large-scale SERDP study to understand the mobility characteristics of variable density Unexploded Ordinance (VD-UXOs) in the swash zone under extreme wave forcing.
The capabilities and limitations of the model in simulating swash zone dynamics are investigated in this study. A near prototype, high-energy wave-breaking process is achieved using a double dam break setup. The flume consists of two reservoirs with separate gates that can be operated simultaneously or at specific intervals. Variations in the gate opening intervals and resting water level front of the first gate yield different bore configurations and wave-wave interactions. Different combinations of gate opening intervals were tested. The water surface elevation, pressure gradients at the toe of the beach slope, and runup are compared against the experiment data. The model effectiveness and some of the inherent challenges associated with the Dual SPHysiscs model are also highlighted. The presented work is a part of a large-scale SERDP study to understand the mobility characteristics of variable density Unexploded Ordinance (VD-UXOs) in the swash zone under extreme wave forcing.
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Integrating nature-based engineering designs and adaptive management strategies for a resilient coastline in North Cove, WA
Hannah Drummond
Hannah Drummond
Washington Department of Ecology
Hannah Drummond is an environmental specialist with the Washington State Department of Ecology Coastal Monitoring and Analysis Program. She works with a team to conduct studies related to coastal natural hazards, coastal erosion, natural resource management, and coastal engineering practices. She holds a B.S. degree in Geology from Saint Lawrence University and recently earned an M.A. degree in Geographic Information Science from Western Washington University.
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Abstract
Abstract
Once nicknamed “Washaway Beach” for its high erosion rates, North Cove, WA has transitioned to a resilient coast by developing and applying innovative nature-based engineering designs and adaptive management strategies. The community located at the entrance to Willapa Bay faced severe, chronic erosion for over a century, often losing tens of meters of upland per year during winter storms that routinely washed away homes and other infrastructure. Following small-scale experiments with placement of quarry spalls along erosion scarps from December 2016 to March 2018, a dynamic revetment spanning about two kilometers of coast was initially constructed in November 2018 along the base of the erosion scarp providing a shallower upper beach slope to dissipate wave energy and enhance sediment deposition. Poorly sorted quarry spalls were used to mimic natural rock slide material, and are an economical alternative to sourcing rounded cobble. Over time, the rock is expected to abrade and round in the high-energy environment to simulate a backshore cobble berm on a natural composite beach.
The dynamic revetment maintenance was coupled with nature-driven adaptive engineering designs and management strategies that incorporate large wood, vegetation, and seaward rock berms. As the revetment accumulated drift logs, other woody debris was introduced above and below the revetment to complement the function of the cobble, building a gentle and stable slope and buffer against storm events. A log groin was constructed and later extended primarily to dissipate infragravity wave energy, but also helped build a sand spit by trapping sediment and woody debris that would otherwise be washed into a nearby drainage ditch. Later, rock berms and rock mounds were placed seaward of the revetment toe for additional wave dissipation. The initial berms were placed along the summer wrack line to enhance the natural summer profile. Later, berms and mounds were added during the winter to stabilize erosion hotspots as they occurred to maintain an overall stable form. The combined rock and wood features contributed to sediment deposition by wind and wave processes and ultimately led to net sediment accumulation. Lastly, vegetation on the upper beach was introduced to facilitate sediment retention and dune-building processes.
The Washington State Department of Ecology Coastal Monitoring & Analysis Program (CMAP) has conducted quarterly monitoring of the project site since June 2018, including topographic surveys, revetment mapping, rock movement tracking, sediment grain-size analysis, and photo monitoring. Additional topographic surveys were performed during winter to determine response and recovery from storm events. This poster provides an overview of the design features described above and gives a brief monitoring update through spring of 2021, two and a half years after the initial construction of the dynamic revetment. An increase in both seasonal and overall vegetation on the upper beach has been observed, and a dynamically stable revetment toe position is shown through beach elevation profiles and revetment mapping results. The monitoring and analysis illustrates how this once rapidly eroding shoreline transitioned to a stable and accreting coastline by integrating multiple complementary design and management techniques determined by natural processes.
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*Virtual Participant
Evaluation of Performance and Resiliency for a Beach and Dune System along the Texas Coast
Dr Himangshu Das
Dr Himangshu Das
US Army corps of Engineers
Dr. Himangshu S. Das graduated from University of South Carolina with a Ph.D. in Civil and Environmental Engineering. Dr. Das serves as the District’s Subject Matter Expert (SME) providing expert guidance in coastal hydrology and hydraulics. Currently he is serving as the technical lead for the Coastal Texas Mega project – $20 million applied research program to better understand coastal risk and resilience to develop and engineer innovative solution to reduce infrastructure risk specific to the Texas coast from Louisiana to Mexico border. Prior to joining at the U.S. Army Corps of Engineers, from 2008 to 2017, Dr. Das served as a tenured Associate Professor at the Department of Civil and Environmental Engineering, Jackson State University (JSU). At JSU, Dr. Das served as Principal Investigators to numerous research projects. At JSU, he had secured and executed about one and half million-dollar worth of applied and research projects that focused on urban, coastal and near-shore processes, and ocean engineering and have authored or coauthored more than 30 peer reviewed technical publications.
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Abstract
Abstract
The upper Texas coastline has been eroding rapidly on an average 2 feet per year to over 20 feet per year in some regions. The Coastal Texas Study has been formulated by the US Army Corps of Engineers in coordination with the Texas General Land Office (GLO) to study Coastal Storm-Surge Reduction Measures (CSRM) and to improve overall resiliency of the entire Texas coastline. Severe storm events in the past along with relative sea level changes (RSLC) have contributed to this shoreline recession which causes billions of dollars of damage. From west to east along the coastline, the study site includes approximately 19 miles in Galveston Island and 26 miles in Bolivar Peninsula. This particular piece of the presentation specifically addresses the feasibility of nature-based solutions such as a dune-beach system along Galveston Island and Bolivar Peninsula to reduce storm surge impacts and shoreline recession. It has been observed that both higher dune elevation and dune core fortification (clay or rock core) perform well against very energetic events such as Ike type of storm. For low energy events, berm elevation and width primarily controls the performance. Further, a dune field configuration has been found to be relatively more effective and resilient. We have assessed that sediment requirements for initial construction range between 100 and 160 cubic yards per linear foot depending on site conditions for a total of approximately 50-million cubic yards for the entire length of the study site. Borrow source identification and lifecycle analyses are also performed to indicate periodic nourishment and maintenance needs.
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