Improvement of urban flood damage estimation using a high‐resolution digital terrain

Abstract

AbstractBecause urban flooding occurs frequently, it is important to calculate the areal extent of flooding based on flood volumes and water levels, and thus, the extent of expected damage can be effectively estimated. In this study, urban inundation from heavy rainfall and the contribution of topographic scales to urban river drainage basins in Seoul, Korea are simulated. A light detection and ranging (LiDAR)‐based 1× 1 m digital elevation model (DEM) and a 1:5,000 digital map‐based 10 × 10 m DEM are used in this study for the storm water management model (SWMM). Using a multi‐dimensional flood damage analysis to estimate economic damage, the asset value of each building type is analyzed in connection with the construction cost of buildings, household ratio, and building area, and then, the building damage is calculated at each flood level based on the percentage of building damage. Based on the analysis, 119.6 and 55.8 M USD in damages are expected to occur according to the 1 and 10 m DEMs, respectively. The results of this study can be used to evaluate alternatives for urban flooding mitigation and an optimal mitigation measure can be suggested among the alternatives because the methods used for predicting floods are examined and the associated damages are accurately estimated using digital terrain data at precise scales.