Flood Vulnerability Analysis in Banyumas Regency, Indonesia

Banyumas Regency, Indonesia, is often hit by recurrent annual floods that affect the local population's physical environments and social conditions. Therefore, a vulnerability analysis is needed to determine potential damage, loss of property, and number of people affected in the wake of floods. The research objectives were to identify and map flood vulnerability in the regency, both in total and by component (social, physical, and environmental). Geographic Information System (GIS) approaches were used to overlay, score, and weigh components and their variables. In the vulnerability assessment, three weighting scenarios were observed: weighting based on Regulation of the Head of the National Disaster Management Agency (NDMA) No. 2 of 2012, equal weighting, and dominance-based weighting. Results indicate that the NDMA scenario produced the broadest and most widely distributed high-vulnerability areas. The other two scenarios showed a comparable spatial distribution pattern with the locus of high total vulnerability on the Serayu River banks in the middle (the entire Purwokerto Municipality) and southern parts of the regency (Banyumas and Kebasen Districts). This can be linked to many settlement areas and their supporting facilities in Banyumas and Purwokerto that are traversed by this major river. As for Kebasen, it lies in a basin abutted by the lower reach of Halang Formation Hills, with the river meandering through its densely populated settlements. © 2025 Institute of Physics Publishing. All rights reserved.