Prediction of Flood Zone Areas for Frankfort, Kentucky, using Lidar Data

Abstract

Flooding is a common, serious, and costly natural disaster. Kentucky is ranked second among flood-related disaster areas in the United States. Preparation of flood zone and flood hazard maps are essential to identify flood risk zones, and then to potentially reduce the impact of flooding. Light Detection and Ranging (Lidar) provides high-resolution and high-accuracy elevation data as input for flood modeling and in studying flood impacts. The objectives of this study are: (1) to use topographic elevation data for delineating flood inundation areas of the Kentucky River at Frankfort; and (2) to demonstrate a flood analysis technique using Lidar as a source of highly accurate elevation data. Lidar point cloud tiles from the Kentucky Geography Network were used to create Triangulated Irregular Networks (TIN), then used to generate water surface elevation. Results showed Lidar-based topography data accurately delineated flood inundation areas and water depth. A simulated flood at a level of 14.77 m, approximating the flood of 1978, inundated 7.85 ha within downtown Frankfort and vicinity, causing considerable physical and monetary damage. Resulting maps of flood inundation areas can be used as supplementary information for flood modeling and analysis. This information can be used in land-use management, town planning, and estimating flood insurance to minimize damage from flooding.