Water Body Extraction and Flood Risk Assessment Using Lidar and Open Data

Abstract

Floods are one of the most serious, common and expensive natural disasters that cause fatalities and considerable economic losses worldwide every year. Climate change has dramatically increased the frequency and the severity of the flood events. In May 2014, 2/3 of Serbia were affected by the floods, more than 400 homes were destroyed while the total economic damage exceeded 1.7 billion euros. This fact causes concern and identifies an urgent need for designing and improving flood mitigation measurements. An important aspect of the flood risk studies deals with the topography of river and floodplain. Digital Elevation Model (DEM) is widely used in order to estimate the flood inundation and associated damages to properties and livelihoods. The resolution and accuracy of a DEM are critical in a flood risk assessment, especially in lowlands area, where the offset of few decimeters in the elevation data has a significant impact on the accuracy of the risk assessment. The accuracy of the publicly available DEMs is relatively low in the level of accuracy required for flood risk assessment. Throughout this paper, the Light Detection and Ranging (LiDAR) was used for water body delineation. Water body extraction from LiDAR data was compared to a publicly available Sentinel-2 satellite image. Also, DEM data were used for flood risk estimations in Vojvodina Province, Republic of Serbia. Flood risk assessment by using the publicly available ASTER SRTM DEM was compared to a flood risk assessment using LiDAR DEM.