Mapping the Semeru lahar-flood hazard of Supiturang Village using the analytical hierarchy process (AHP) method

Abstract

Supiturang is one of the villages in Kecamatan Pronojiwo, Kabupaten Lumajang that sits on the lahar flow path of Semeru Volcano. The village constantly faces a lahar-flood hazard, inevitably impacting the local community. Therefore, this paper aims to map the lahar-flood hazard of Supiturang village using the analytical hierarchy process (AHP) method. The main parameters are 1) slope (%), 2) distance from drainage (m), 3) elevation (m ASL), 4) rainfall (mm), and 5) land cover (water body/bare land/forest/grassland/plantation/ricefield/mixed agriculture/built-up area). This research is a descriptive-quantitative study that used survey and geographic information system (GIS) approaches. The result showed that the lahar-flood hazard class of Supiturang varies from very low, low, moderate, high, to very high. The very high hazard class is distributed near the lahar flow path. Despite most settlements being in the moderate hazard class, some are in the high and very high hazard class. The findings from this research can advantage the further improvement and development of evacuation routes, assembly points, refuges, observatory stations, and other related Semeru Volcano disaster risk mitigation actions.