Analisis Daerah Rawan Longsor Berdasarkan Aktivitas Manusia dengan Sistem Informasi Geografis (SIG) di Kabupaten Dairi

Abstract

Landslides are ground movements that are influenced by various natural physical properties, including land use and infrastructure as well as geological structures, soils, drainage patterns, and slopes and landforms. Dairi Regency, located in the northwest of North Sumatra Province, has an area of 191,625 hectares or about 2.68% of the province's area of 7,160,000 hectares. Most of the highlands and hills of Dairi Regency are located between 98000' and 98030' and 2015' and 3000'N. The tropical rainy climate is caused by most of the area being mountains and hills with different slopes. The capital of Dairi Regency, Sidikalang City, is located at an altitude of 1,066 meters above sea level. The mapping of landslide potential areas was conducted in Dairi Regency with the estimation model referring to the Ministerial Regulation of the Department of Public Works No. 22 Year 2007. The cause of landslides is one aspect of human activity which includes cropping patterns, excavation and slope cutting, pond printing, drainage, construction, population density, and mitigation efforts. Landslide vulnerability mapping using Geographic Information System (GIS) was conducted by weighting and overlaying the parameters using QGIS software. Based on the results of the analysis, 5 (five) vulnerability risk classes were obtained. For risks with a low vulnerability level of 92.87% or an area of 1651.42 km2 , medium by 7.01% or an area of 124.737 km2 , and high by 0.12% or an area of 2.095 km2 .