High Resolution Modeling of Storm Surge Inundation

Featuring Jochen Schubert, Ph.D.

Postdoctoral Researcher

Department of Civil and Environmental Engineering

The Henry Samueli School of Engineering,  UC Irvine

Free and open to the public

Abstract:

Storm surge modeling has been a topic of research for the last 30 years, but a major increase in research activity has been observed in the last decade. This can be attributed to increased computer processing power, wider availability of geospatial data, and the occurrence of major storm related catastrophes in the U.S., such as hurricanes Charley, Ivan, Frances, Katrina, Rita, Wilma, Gustav, and Ike.

Storm surge modeling efforts have largely focused on predicting the height and timing of the surge as it strikes the coastline. One challenge is that storm surge modeling requires consideration of a wide range of spatial and temporal scales, from surge formation at the scale of an extratropical depression (over 103 km) to its impact which may be important at scales of 10 m or less for damage assessment purposes. This has motivated the extensive use of unstructured grid models for storm surge modeling because unstructured grids easily allow for a gradation of mesh resolutions.

The presented research topic, aims to further advance the design and parameterization of unstructured grids for computationally efficient, high-resolution storm surge inundation modeling, by using global to local scale geospatial data. Hurricane Katrina and its inundation of the Mississippi coastline in Hancock, Harrison and Jackson counties is the subject of the modeling, based on the wealth of available data, including LiDAR topography, High Water Marks (HWMs) and advisory Base Flood Elevations (BFEs) reported by FEMA. The computational grid spans the Gulf of Mexico to resolve surge formation by wind action and it is increasingly refined near the coastline to accurately depict flood depth and velocity. Adopted data will therefore range from offshore bathymetry to river soundings, or regional topography to local embankments and channels. Findings will allow to benchmark the accuracy with which flood extent can be predicted, and to document significant model sensitivities that bear on successful prediction. The latter is particularly important given the critical role that storm surge inundation predictions play in emergency preparedness and response.