Landslide Susceptibility Mapping Using GIS-Based Analytical Hierarchy Process in Pejawaran District, Banjarnegara

Abstract

Landslide susceptibility mapping is an important tool for identifying relatively unstable zones and facilitating disaster mitigation and land-use planning. This study assesses landslide susceptibility in Pejawaran District, Banjarnegara, Central Java, Indonesia, using a GIS-based Analytical Hierarchy Process (AHP). Six conditioning factors were integrated: distance to road, normalized difference vegetation index (NDVI), distance to stream, lithology, elevation, and slope. Pairwise comparison was used to assess the relative importance of these factors. The resulting weights were: distance to road (28%), NDVI (22%), distance to stream (17%), lithology (14%), elevation (10%), and slope (9%). The final landslide susceptibility map was created by combining the weighted thematic layers in a GIS environment. The 54.02 km² study area was classified into five susceptibility levels: very low (8%), low (19%), moderate (28%), high (28%), and very high (16%). High- to very-high-susceptibility areas are mainly concentrated in the central, northern, and eastern parts of the study area, while the western and southwestern sectors generally show lower susceptibility. The spatial distribution of the landslide inventory closely matches the moderate-to-high susceptibility zones. These results indicate that the GIS-AHP approach provides a practical preliminary framework for identifying landslide-prone areas in Pejawaran District.