Flood susceptibility mapping using analytical hierarchy process (AHP) in Bantul Regency, special region of Yogyakarta, Indonesia

Abstract

Floods are the most frequent natural disasters and enormously impact many sectors and human lives. It may devastate natural environments and infrastructure and cause loss of life. Flood susceptibility mapping is helpful to identify the risk zones. By combining the use of the Analytical Hierarchy Process (AHP) method and the GIS techniques, this study aims to assess the flood susceptible area in Bantul Regency, Yogyakarta. Bantul Regency has experienced floods every year as it is positioned as a downstream area and weather variability. Seven criteria are used to analyze the flood susceptible areas in Bantul Regency, i.e., elevation, slope, land use, river buffer, soil, annual rainfall, and maximum daily rainfall. This study highlighted that around 44.53% of areas are categorized as moderate to high susceptible areas, and 55.47% are considered low to moderate probability of flooding. The most influencing criterion is the river buffer since many settlement areas in the Bantul Regency are transverse by large rivers and tributaries. It increases flooding susceptibility. This study may provide a flood risk understanding to policymakers and relevant stakeholders to prepare mitigation plans.