Conference: ADCIRC Users Meeting 2023

JL Woodruff, JC Dietrich, D Wirasaet, AB Kennedy, D Bolster. “Storm Surge Predictions from Ocean- to Subgrid-Scales.” ADCIRC Users Meeting, Baton Rouge, Louisiana, 8 Jun 2023.

JS Knowles, JC Dietrich. “Storm Surge Predictions at Hyperlocal Sites.” ADCIRC Users Meeting, Baton Rouge, Louisiana, 8 Jun 2023.

TA Cuevas López, BJ Tucker, JC Dietrich. “Prediction of High-Resolution Maps of Hurricane-Driven Coastal Flooding Using Machine Learning.” ADCIRC Users Meeting, Baton Rouge, Louisiana, 8 Jun 2023.

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News: Department Social Media

2023/06/01 — NCSU Civil, Construction, and Environmental Engineering
YouTube

Jack Voight was featured on social media in a video about his summer research in our REU program. He is running simulations of storm surge and coastal flooding as part of a project about total water levels at coastal infrastructure. Glad he is part of our team!

Jessica Gorski defends MS Thesis

We celebrate another successful defense! Jess defended her MS thesis to a mix of in-person and remote attendees, who had a lot of interest in her research on real-time forecasts of coastal erosion. Congrats to Jess!

Jessica starts her thesis defense.

Thesis Defense: Jessica Gorski

Jessica Gorski. “Deterministic, dynamic model forecasts of storm-driven erosion.” Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina, 1 Jun 2023.

Johnathan Woodruff defends PhD Dissertation

We celebrate another successful defense! Johnathan defended his PhD dissertation to a mix of in-person and remote attendees, who had a lot of interest in his research on subgrid corrections for storm surge modeling. Congrats to Johnathan!

Johnathan starts his dissertation defense.

Dissertation Defense: Johnathan Woodruff

Johnathan Woodruff. “Storm-driven coastal flooding predictions from subgrid- to ocean-scales.” Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina, 19 May 2023.

Numerical Extensions to Incorporate Subgrid Corrections in an Established Storm Surge Model

Inundation models represent coastal regions with a grid of computational points, often with varying resolution of flow pathways and barriers. Models based on coarse grid solutions of shallow water equations have been improved recently via the use of subgrid corrections, which account for information (ground surface elevations, roughness characteristics) at smaller scales. In this work, numerical approaches of an established storm surge model are extended to include subgrid corrections. In an attempt to maintain continuity with existing users and results, model extensions were limited to those needed to provide basic subgrid capabilities, and included two major additions. First, a finite volume method is used to incorporate corrections to the mass and momentum equations using high-resolution ground surface elevations. Second, the no-slip condition imposed on the B-grid wet/dry interface in the model is modified to a slip condition to enable flows in channels with widths comparable to cell size. Numerical results demonstrate these numerical extensions can significantly enhance the accuracy of the model’s predictions of coastal flooding, with low additional computational cost.

A Begmohammadi, D Wirasaet, AC Poisson, JL Woodruff, JC Dietrich, D Bolster, AB Kennedy (2023). “Numerical extensions to incorporate subgrid corrections in an established storm surge model.” Coastal Engineering Journal, 65(2), 175-197, DOI: 10.1080/21664250.2022.2159290.

Storm Surge Predictions from Ocean to Subgrid Scales

The inland propagation of storm surge caused by tropical cyclones depends on large and small waterways to connect the open ocean to inland bays, estuaries, and floodplains. Numerical models for storm surge require these waterways and their surrounding topography to be resolved sufficiently, which can require millions of computational cells for flooding simulations on a large (ocean scale) computational domain, leading to higher demands for computational resources and longer wall-clock times for simulations. Alternatively, the governing shallow water equations can be modified to introduce subgrid corrections that allow coarser and cheaper simulations with comparable accuracy. In this study, subgrid corrections are extended for the first time to simulations at the ocean scale. Higher-level corrections are included for bottom friction and advection, and look-up tables are optimized for large model domains. Via simulations of tides, storm surge, and coastal flooding due to Hurricane Matthew in 2016, the improvements in water level prediction accuracy due to subgrid corrections are evaluated at 218 observation locations throughout 1500 km of coast along the South Atlantic Bight. The accuracy of the subgrid model with relatively coarse spatial resolution (ERMS = 0.41 m) is better than that of a conventional model with relatively fine spatial resolution (ERMS = 0.67 m). By running on the coarsened subgrid model, we improved the accuracy over efficiency curve for the model, and as a result, the computational expense of the simulation was decreased by a factor of 13.

JL Woodruff, JC Dietrich, D Wirasaet, AB Kennedy, D Bolster (2023). “Storm surge predictions from ocean to subgrid scales.” Natural Hazards, 117, 2989–3019, DOI: 10.1007/s11069-023-05975-2.