Simplified Methodology for Urban Flood Damage Assessment at Building Scale using Open Data

Abstract

Flooding is a hazardous natural disaster that causes extensive damage to people and infrastructure, especially in cities. Since the content and scope of public data disclosed by each country and city differs, general flood damage assessment methods have not yet been developed. In other words, flood damage assessment methods need to be tailored to each city's public data. This study developed a methodology to easily estimate flood damage based on public data. The method can be applied to various situations and locations. The proposed urban flood damage assessment method uses a geographic information system (GIS) and open data at building scale to provide detailed damage information. Flooded areas are established using GIS, and building inundation heights are obtained from the flood map. Economical losses are derived from inundation data by calculating numbers of loss for residential buildings, industrial buildings, and human life. To validate the proposed method, a simulation using probabilistic flood map in the Masan Bay area, Republic of Korea, was conducted. In the simulation, recently published building and census data were used. The urban flood damage assessment was performed using a 200-year return period coastal flood scenario. The simulation results show that the proposed assessment method provides more detailed information on damage at the building level than regional scale damage assessment results. The results confirm the potential to improve policy decision-making and to reduce the detrimental impacts of urban flooding by adopting the proposed assessment method.