Analisis Spasial Kerawanan Longsor di Daerah Aliran Sungai (DAS) Belumai Provinsi Sumatera Utara

Abstract

Information on landslide vulnerability in watersheds is essential for natural disaster reduction and sustainable development. Landslides endanger infrastructure, human life, and the environment. One of the critical watersheds that has not been studied is Belumai watershed in North Sumatra Province. This study aims to analyze the distribution of landslide vulnerability in Belumai watershed by utilizing geographic information system (GIS). This research uses scoring and weighting methods on factors that affect landslide vulnerability, namely rainfall, slope, land cover, soil type, and earthquake. The results showed that the dominating landslide vulnerability class in Belumai watershed is low vulnerability of 52,342.92 Ha (67.45%), followed by medium vulnerability of 21,243.01 Ha (27.37%), then very low vulnerability of 2,044.29 Ha (2.63%), and high vulnerability class of 1975.16 Ha (2.55%). High vulnerability is mainly found in the upstream area of the watershed and on the riverbanks. Mitigation to prevent landslides is important especially in the very high and high vulnerability classes to minimise disaster risk.