Analisis Daerah Rawan Longsor Berdasarkan Faktor Alam Menggunakan Sistem Informasi Geografis (SIG) (Studi Kasus: Kabupaten Padang Lawas)

Abstract

Landslide is a land movement that occurs due to soil movement that causes unstable soil conditions. Padang Lawas Regency is one of the areas prone to landslides due to irregular rainfall, morphological conditions in the form of plains with hills of medium height and several medium-flow rivers that flow throughout the year. To identify the level of landslide vulnerability and landslide prone areas in Padang Lawas Regency, researchers utilized mapping technology with Geographic Information System (GIS) and Satellite Imagery. This research was conducted based on natural factors with parameters of slope, soil condition, rock type, rainfall, slope drainage, seismicity, and vegetation/land cover. In this research, a weighting method was used where each parameter was given a score and then multiplied by the percentage of the weight value and also used the overlay method. Q-GIS software version 3.22.16 was used for this research. From the analysis, 5 (five) landslide vulnerability classes were obtained. Very low vulnerability class is 1,998 km2 or 0.051%, low vulnerability class is 378.724 km2 or 9.577%, medium vulnerability class is 2,028.6 km2 or 51.298%, high vulnerability class is 1,128.47 km2 or 28.536% and very high vulnerability class is 416.762 km2 or 10.539%.