RAPID: Revisiting the compounding storm surge and extreme precipitation events on coastal flooding during hurricane Florence using field data

Clemson University, Clemson SC

Investigators

Abstract

During September 2018, Hurricane Florence wreaked havoc in the Carolinas with devastating heavy rainfall (20-40 inches), record sea-water storm surges, and consequent coastal flooding with reported inundation depths of as high as 6 feet. The impacts included major damage to the surrounding region and a number of hurricane-related deaths. The city of Wilmington, NC entirely was cut off by historic flooding from the Cape Fear River. The dense population and development along its coastline continues to leave South Carolina communities highly vulnerable to coastal flooding from these seasonal hurricane events. The major causes of hurricane-related flooding events are the coastal storm surge caused by extreme winds and/or the occurrence of concentrated and extreme precipitation within vulnerable, flood prone areas. During flooding events, perishable data, such as high-water marks, are potential evidence of the highest water levels during a flood and they provide valuable data for understanding extreme flood events. In this study, valuable information will be obtained from such perishable data through field visits. The overall objective of this research project is to visit the locations of coastal flooding to investigate (a) the reliability of the weather forecast in terms of different spatio-temporal scales for extreme rainfalls, and (b) the joint probability of extreme rainfall and storm surge to gain insight into an increase in flood risk under hurricane scenarios. This research projects aims to amass data with which stakeholders can improve their current design standards for future flooding preparedness. The PI also expects (c) to utilize observed and collected perishable data in developing a statistical modeling framework both to generate spatial risk maps and to identify critical vulnerabilities of important coastal infrastructure regarding compound events. Such information is critical for maintaining coastal infrastructure networks and for providing alerts during extreme events. This research project will advance knowledge about the influence of extreme rainfall and storm surge on coastal flooding as well as the potential impact of such events on environmental sustainability. By documenting perishable data, the research project provides an excellent opportunity to study the compounding effect of two extreme weather events at multiple locations and to estimate the return period for such events with respect to historical periods. The research results will be used to develop strategies for improving awareness about compound extreme events amongst stakeholders to minimize flooding impacts. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.