Spatial-Temporal Changes of Flood Risk in the United States

Keywords: flood risk, flood zone, exposure analysis, vulnerability, USA
Session Type: Virtual Paper Abstract
Day: Saturday
Session Start / End Time: 2/26/2022 02:00 PM (Eastern Time (US & Canada)) - 2/26/2022 03:20 PM (Eastern Time (US & Canada))
Room: Virtual 28

Abstract

Floods are the most recurrent and common disaster leading to significant fatalities and economic losses in the United States. Therefore, extracting baseline information on flood risk and its temporal evolution is essential to formulate flood risk reduction strategies. Flood risk is defined as the product of flood hazard, exposure, and vulnerability. Previous studies have investigated the three elements separately, but estimations of flood risk considering all three factors are rare. The purpose of the study is to evaluate both nationwide and county-based changes in flood risk in the US from 2001-2021. Specifically, the study aims to answer the following questions: a) what proportions of population and urban areas are exposed to different levels of flood threats? b) which communities suffered high flood risk? c) How people response to flood risk by avoiding dwelling and development in flood zones? d) trends of flood exposure and risk over time. The U.S. Federal Emergency Management Agency’s (FEMA) 100-year and 500-year flood maps, world population dataset, land cover data, and census data were used in this study. By combining the flood maps and the world population dataset, the exposure of population and their heterogeneous distribution to 100 and 500-year-flood at the micro-level were estimated. Local Moran’s I and geographically weighted regression were used to analyze variations of flood exposure and risk in different counties. This study will deliver a deeper understanding of the spatial patterns of flood risk and their temporal variations from 2001-2021, and expose the general trend and departures from that trend.