Analisis Daerah Rawan Longsor Berdasarkan Faktor Alam Menggunakan Sistem Informasi Geografis (Sig) (Studi Kasus: Kabupaten Dairi)

Abstract

Landslide is an incident in which the displacement of slope-forming material in the form of rocks, soil, and vegetation moves down or out of the slope, resulting in changes in the form of the land on the slope. Dairi District is one of the areas that are prone to landslides due to its hilly and heaving topography, along with many steep and sharp slopes. To identify the level of landslide vulnerability and the deployment area of landslide-prone areas in Dairi District, the researchers used a mapping technology with Geographic Information System (GIS) and Satellite Imagery. This research is based on Peraturan Menteri Pekerjaan Umum No.22/PRT/M/2007 regarding areas prone to landslides. The parameters used in this study were the slope, rock type, soil type, rainfall, seismicity, slope water management, and vegetation. The method used is weighting, in which each parameter is given a score and then multiplied by the percentage of the weighted value, coupled with the method of overlapping. The software used is Q-GIS. From the results of the mapping analysis, the lowlevel landslide vulnerability has an area of 670,3820 km², the moderate level landslide vulnerability has an area of 481,8174 km², and the low level landslide vulnerability has an area of 883,8016 km². Concerning the level of landslide vulnerability per sub-district in Dairi District, it has a moderate level of landslide vulnerability