Mapping Greater Bandung flood susceptibility based on multi-criteria decision analysis (MCDA) using AHP method

Floods are natural disasters caused by certain factors, and these floods can cause a lot of material or immaterial losses. Bandung Raya is an area with coverage of two cities and two districts consisting of Bandung City, Cimahi City, Bandung Regency, and West Bandung Regency. Flood susceptibility mapping can be done in various ways, but one of the most effective ways is by using the MCDA-based AHP method. This study aims to map the susceptibility of flood risk in the Greater Bandung area using the analytical hierarchy process (AHP) multi-criteria decision analysis (MCDA) model, as well as validating the results obtained. The use of AHP MCDA in this research is by giving weight to each conditioning factor, and applying it by means of overlay weighting technique in ArcGIS 10.8 software. This study found that the flood risk criteria obtained were four classifications: (1) low risk; (2) quite risk; (3) high risk and (4) extreme risk. Most areas that get quite risk classification are Cimahi City, high risk in Bandung Regency, and high risk in Bandung Regency. In addition, the results of the validation by comparing the map acquisition with the flood maps that occurred in 2002-2022 get an average ROC curve percentage of 76.4%, and these results show that the Bandung Raya flood risk susceptibility map is valid. Based on the conditioning factors used, nine factors such as NDVI, TWI, LU/LC, Rainfall, Slope, Elevation, Distance from Road, and Distance from River can be used as valid conditioning factors.