Flood Hazard Assessment Between 2015 and 2019 Using Updated FEMA Floodplain Data in Galveston County, Texas

Abstract

Coastal flooding in America has caused large-scale changes with many communities seeing increased flooding. Flooded communities, collapsed bridges, and obstructed roads are some of the lasting effects that can be devasting if communities are not well prepared for flooding disasters. The Federal Emergency Management Agency (FEMA), which releases Flood Insurance Rate Maps (FIRM) that illustrate the National Flood Hazard Layers (NFHL) across the United States, is responsible for communicating flood risks for communities across the United States. These flood hazard maps are scheduled to be routinely updated every 5 years by FEMA and are intended to help communities properly prepare properties for their associated risk level against flooding. We present an analysis of the coverage of the 2015 and 2019 FEMA flood hazard zones in Galveston County, including changes in the areal extent, building footprints, and parcel count for each flood hazard zone. Initial data manipulation and analysis are conducted in ArcGIS version 10.7.1 while the statistical analysis is finished in Microsoft Excel.