Urban Flood Risk Assessment in Sidoarjo, Indonesia, Using Fuzzy Multi-Criteria Decision Making

Indonesia is very vulnerable to flooding due to urbanization of land use, industrialization and made worse by climate change. Sidoarjo is an urban area that frequently experiences regular flooding every year. The flooding break up local traffic, disrupting economic distribution and transportation routes. Minimum information about areas that are often flooded causes a lack of people and government attention to the effects of floods. In this paper, we develop a Fuzzy approach to determine the level of urban flood risk in Sidoarjo. The parameters consist of flood inundation, rainfall, population affected, and drainage. The Fuzzy sets produce fuzzy membership values, and evaluation rules determine the level of flood disaster in each village in Sidoarjo, classified into three levels of vulnerability, they are high, medium and low level of flood vulnerability. Analysis of the results of the calculation of flood risk assessment with Fuzzy multi-criteria decision making (FMCDM) shows a good result with accuracy of 66% compared to the analysis of the Sidoarjo Regional Disaster Management Agency inundation data. However, in reality flood risk is not only caused by inundation factor, the FMCDM method is represented a better assessment in real world. The spatial decision support system using geographical information systems (GIS) provides effective, efficient and useful in flood risk management for local and national governmental agencies.