HIGH-RESOLUTION FLOOD MAPPING IN NORTHWEST ARKANSAS USING LIDAR AND GOOGLE EARTH ENGINE

In recent decades, Arkansas has experienced a noticeable shift in climate patterns, resulting in an increase in the frequency and intensity of floods. Concurrently, Northwest Arkansas (NWA) has witnessed significant population growth. Flood-prone areas in NWA are a critical concern due to their susceptibility to inundation, primarily attributed to the region's complex topography, outdated data, and the inability to detect small-scale variations in current flood risk maps.

This study aims to improve flood assessment accuracy by generating higher-resolution flood maps with a 1-meter Digital Elevation Model (DEM) extracted from Light Detection and Ranging (LiDAR) topographic data, supported by the cloud computing capabilities of Google Earth Engine. Monthly precipitation records from 1982 to 2022 were retrieved from the Daymet dataset, and flow directions and accumulations were defined using high-resolution satellite imagery. Natural breaks were used to classify the DEM and reclassify all dataset layers. Influential factors were then weighted according to their relative importance.

Our study produced a new flood map with 1-meter spatial resolution for the region, identifying previously unrecognized flood-prone areas in Madison County and concentrated clusters of high to very high-risk areas in Benton County. These areas are in newly urbanized regions, intensifying the flood risk. We hope that our new flood map will enable the local authorities to improve their emergency response plans and mitigation strategies.

Keywords

Flood Risk Assessment, LiDAR Topographic Data, Climate Change Impact, Urban Flooding