GEOSPATIAL ANALYSIS OF FLOOD RISK FROM STORM SURGE AND SEA-LEVEL CHANGE ON THE TEXAS COAST

Regions that constitute our planet’s coastlines are some of the most dynamic on Earth. Storm waves, high tide, occasional tsunamis and hurricanes, in combination with immense geological processes make these locations vulnerable to a variety of natural hazards. Additionally, anthropogenic induced climate and land use change will likely contribute to more severe weather events and coastal flooding. In North America, the coast of Texas has been historically one of the primary targets for tropical storms and hurricanes with the latter being related to greatest hazards and risk. As the population along the shores of Texas continues to grow in a changing climate, so does the risk of hurricane-induced flooding. Although rainfall presents a significant flood risk, storm surge inundation has been proven historically to be the most dangerous and devastating. In this context, this study aims to develop a probabilistic model for predicting future hurricane climate along the Texas coast and analyze potential flood risk from storm surge and sea-level change. Such information system is essential for determining potential risk posed by the combination of sea-level change and storm surge inundation affecting this coastal region. The statistics are also a fundamental part of flood and surge frequency analysis required by National Flood Insurance Program to insure residences and businesses against any damage caused by flooding. The method for storm surge prediction in this study involves geospatial modeling and utilizes the “Sea, Lake and Overland Surges from Hurricanes” (SLOSH), a numerical shallow water equation model developed by the National Weather Service. Available SLOSH model data was used to model storm surge inundation under four different sea-level scenarios for Galveston and Corpus Christi Bay basins. The generated Category 5 storm surges for Galveston Bay and Category 4 for Corpus Christi Bay basins reveal temporary and permanent inundation caused by storm surge and sea-level change respectively. Besides, with the applied sea-level rise scenarios, these low-lying coastal areas observe an increase in magnitude and extent of areas inundated during storms.