Breaking Wave-Induced Rapid Beach Profile Evolution in the Inner Surf and Swash Zones
The Breaking wave-induced rapid beach profile evolution in the inner surf and swash zones project will investigate the hydro-morphodynamic feedback mechanisms driving major sediment transport events (e.g., momentary bed failure, liquefaction, sediment bursts, and sheet flow) and the resulting cross-shore morphodynamics in the inner surf and swash zones via laboratory experiments and numerical simulations. We will carry out a series of experiments in the ERDC 3-m wave flume to obtain high-resolution inner surf and swash zone measurements of pore pressure gradients, bed load, suspended load, intra-wave velocity profiles, bed evolution, and surface turbulence. We will quantify the relative importance of physical processes (e.g., wave-breaking turbulence, wave-backwash interaction) driving major sediment transport events. Measured data will be used to inform and develop simulations using the high-resolution, turbulence-resolving, two-phase model, SedInterFoam, to simulate major sediment transport events in the inner surf and swash zones. Ultimately, the result of this study will improve or develop new parameterizations for local and regional scale coastal morphodynamic predictions, especially during and after storm events.
Lead PIs: Ryan Mieras, Jack Puleo, Blair Johnson, Tian-Jian Hsu
Photo Description: Turbulent breaking wave bore front in a large wave flume with a conductivity concentration profiler capturing sheet flow sediment concentration profiles and rapid bed level evolution in the swash zone. This novel sensor was developed at UNCW and the University of Delaware (Co-PI).
Sediment Transport Over the Nearshore Environment (STONE): Linking Nonlinear Wave Effects Across the Shoaling and Breaking Zone
In the nearshore environment, shoaling and breaking waves suspend and transport sediment, driving beach erosion or accretion. Rapid spatial and temporal variability in wave transformation processes leads to a wide range of field-based hypotheses and conclusions drawn regarding the role of wave-driven sediment transport from the inner shelf to the break point. As such, laboratory studies are a critical tool to better understand sediment transport and suspension within the nearshore environment. Sediment Transport Over the Nearshore Environment (STONE): Linking nonlinear wave effects across the shoaling and breaking zone will address how nearshore sediment suspension and transport are effected by (1) wave-breaking-generated turbulence and coherent structures and (2) nonlinear interactions and coupling of infragravity and sea-swell waves in the shoaling zone. This project pairs laboratory findings with numerical modeling to inform parameterizations and contextualize observed sediment transport processes, essential to predict beach morphology evolution.
Lead PIs: Morteza Derakhti, Christie Hegermiller, Gregory Wilson, Christine Baker, Chris Chickadel, Melissa Moulton
Photo Description: Enhancing understanding and improving parameterizations of wave-driven nearshore sediment suspension and transport.
Augmenting Hurricane Sentinel Towers with Chemical and Biological Sensors
The Augmenting Hurricane Sentinel Towers with Chemical and Biological Sensors research seeks to improve our understanding of extreme events through the continuous measurement of atmospheric and hydrographic parameters on the shoreline during a landfalling hurricane. The team is leveraging ongoing interdisciplinary research at the University of Florida, which has resulted in the development of hurricane monitoring towers called Sentinels. The team is adding water quality sensors and an acoustic Doppler current profiler (ADCP) with directional wave capabilities to a Sentinel tower. The Sentinel tower will be deployed on the shoreline prior to a landfalling hurricane. The addition of the ADCP and water quality sensors will allow us to characterize chemical and biological fluxes on the shoreline during an extreme event. The Sentinel tower provides a robust, integrated platform for measuring the arrival and progression of tropical cyclone winds, associated storm surge and waves, and erosion. Adding the ADCP and water quality sensors will enable the discovery of new, fundamental knowledge related to hurricane wind-wave interactions, surge-wave-current dynamics, and dependencies between storm surge and water quality parameters.
Lead PIs: Bret Webb, Elise Morrison
Photo Description: The University of Florida deploys a Sentinel tower near Daytona Beach, Florida.
Scaling Transport in Nearshore Vegetated and Non-Vegetated Environments: Sediment, Seeds, and Stiffness
The relationship between our dynamic beaches and neighboring salt marshes plays a critical role in the flooding of our coastal communities. The health and composition of marsh ecosystems relies on fluid exchange and sediment supply from marine environments through tidal inlets, tributaries, flooding due to inundation or wave-driven overland flow over the coastal dunes. This effort targets the onshore transport of sediment (and overwash) due to ripple migration and in the presence of vegetation. Scaling Transport in Nearshore Vegetated and Non-Vegetated Environments: Sediment, Seeds, and Stiffness seeks to address the scaling of sediment and mass transport in nearshore vegetated and non-vegetated environments. The objective is to evaluate the scaling laws associated with net onshore mass and momentum transport resulting from oscillatory flows. The project findings will provide necessary insight when evaluating the translation of empirical relationships derived from small-scale laboratory studies to the field. The laboratory observations will provide critical insights into upscaling of small-scale studies to full scale environments. This work will be particularly connected to the USACE Engineering with Nature program objectives and may inform future nature-based solutions, particularly in colder climates.
Lead PIs: Diane Foster, Theresa Oehmke, Tracy Mandel
Quantifying Morphological Changes Driven by Oyster Reef Breakwaters Under Different Tidal and Wave Conditions to Inform Restoration Strategies
Oyster reef ecosystems are gaining increasing attention for their resilience and self-maintenance properties. Reefs function as foundation habitats supporting aquatic food webs and providing numerous ecosystem services. For instance, they can mitigate erosion and favor deposition in adjacent coastlines. For these reasons, reef restoration is growing in practice. However, there is a gap in understanding which physical processes drive sediment transport around an oyster reef under different waves and tides and for different reef locations and geometries, as identified by our end-users (see letters of support). Therefore, there is a critical need to systematically quantify the efficacy of oyster reefs in retaining sediments and favoring shore progradation. Without this quantification, optimal restoration strategies cannot be implemented. To meet this need, Quantifying morphological changes driven by oyster reef breakwaters under different tidal and wave conditions to inform restoration strategies will run physical experiments at the Large-Scale Sediment Transport Facility (LSTF) at the Coastal and Hydraulics Laboratory (CHL) using reefs made of oyster castles and covered by oyster shells. A numerical model will be calibrated using the collected data and will be used to predict the morphological impact of the reef beyond the reduced parameter space of the physical model. Our main goal is to understand the fundamental processes dictating sediment transport and morphological variations around a restored oyster reef. This will allow us to determine which reef geometry maximizes the aggradation for given tidal and wave conditions. Our research will benefit the local planning and regulatory authorities that help implement management and development decisions.
Lead PIs: Alberto Canestrelli, William Nardin, Luca Martinelli (University of Padova), Rafael Tinoco, Savanna Barry