Conference: YCSECA 2022

Emulator for Eroded Beach and Dune Profiles due to Storms

Dunes and beaches are vulnerable to erosion during storm events. Numerical models can predict beach response to storms with fidelity, but their computational costs, the domain-specific knowledge necessary to use them, and the wide range of potential future storm and beach conditions can hinder their use in forecasting storm erosion for short- and long-term horizons. We develop an emulator, which is an efficient predictive model that behaves like a numerical model, to predict the morphologic response of the subaerial beach to storms. Specific emphasis is placed on providing antecedent beach states as an input to the emulator and predicting the post-storm profile shape. Training data include beach profiles at multiple stages in a nourishment life cycle to assess if such a framework can be applied in locations that nourish as a coastal defense policy. Development and application of the emulator is focused on Nags Head, North Carolina, which nourishes its beaches to mitigate hazards of storm waves, flooding, and erosion. A high-fidelity, process-based morphodynamic model is used to train the emulator with 1250 scenarios of sea-storms and beach profiles. The post-storm beach state is emulated with a parameterized power-law function fit to the eroded portion of the subaerial profile. When the emulator was tested for a sequence of real storms from 2019, the eroded beach profiles were predicted with a skill score of 0.66. This emulator is promising for future efforts to predict storm-induced beach erosion in hazard warnings or adaptation studies.

A Gharagozlou, DL Anderson, JF Gorski, JC Dietrich (2022). “Emulator for Eroded Beach and Dune Profiles due to Storms.” Journal of Geophysical Research: Earth Surface, 127(8), e2022JF006620, DOI: 10.1029/2022JF006620.

Poster: Spring 2022 Conferences

JF Gorski, JC Dietrich, RA Luettich, MV Bilskie, D Passeri, RC Mickey. “Toward deterministic, dynamic model forecasts of storm-driven erosion.” 2022 Ocean Sciences Meeting, Virtual Meeting, 2 March 2022.

JF Gorski, JC Dietrich, RA Luettich, MV Bilskie, D Passeri, RC Mickey. “Toward deterministic, dynamic model forecasts of storm-driven erosion.” Environmental, Water Resources, and Coastal Engineering Research Symposium, North Carolina State University, 4 March 2022.

Toward deterministic, dynamic forecasts of storm-driven erosion

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Virtual Conference: 2022 Ocean Sciences Meeting

News: Jessica Gorski Featured in Lenovo Video

2021/11/15 – Intel + Lenovo
Coastal Computing

Our research into real-time erosion predictions using XBeach was featured in a recent video by Lenovo and CNN. Jessica Gorski describes how we are exploring the use of 1D transect models to predict erosion during storms.

Lenovo provides hardware and support for the HPC services at NC State. The video was produced as branded content for CNN, and it was featured on the CNN web site and social media.

The video required two days of shooting with a team of directors, photographers, audio specialists, and production assistants. Click below to see photos of the production.

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Formation of a Barrier Island Breach and Its Contributions to Lagoonal Circulation

Barrier islands are a primary coastal defense and often experience erosion during storms. When they fail due to storm-induced breaching, there can be significant changes to the small- and large-scale hydrodynamics and morphodynamics of the region. In this study, we explore the formation of a breach on Hatteras Island, North Carolina, during Isabel (2003) and the subsequent flooding into Pamlico Sound. Two-way coupling of high-fidelity, high-resolution numerical models for coastal erosion and flooding enables a better understanding of the formation of the breach, as well as scenarios of the breach’s effects on the circulation in the region. The breach connecting the ocean to the sound formed during the day of landfall. It is shown that, during the storm, overwash and inundation from the ocean led to deterioration of the beach and dunes, and then after the storm, the creation of channels through the island was sensitive to elevated water levels in the lagoon. Then flooding scenarios are considered in which the ground surface of the hydrodynamic model was (a) static, updated with the (b) pre- and post-storm observations, and updated dynamically with (c) erosion model predictions and (d) erosion model predictions with elevated lagoon-side water levels. The model results show that the breach has region-scale effects on flooding that extend 10 to 13 km into the lagoon, increasing the local water levels by as much as 1.5 m. These results have implications for similar island-lagoon systems threatened by storms.

A Gharagozlou, JC Dietrich, TC Massey, DL Anderson, JF Gorski, MF Overton (2021). “Formation of a barrier island breach and its contributions to lagoonal circulation.” Estuarine, Coastal and Shelf Science, 262, 107593, DOI: 10.1016/j.ecss.2021.107593.