Analisis Tingkat Risiko Bencana Tanah Longsor Berbasis Sistem Informasi Geografis (SIG) (Studi Kasus: Kecamatan Barus Jahe, Kabupaten Karo)

Abstract

Landslide is the event of the release of some types of soil or rock from the slope to a point lower than the previous condition following the direction of gravity triggered by natural and human factors. Barus Jahe sub-district is an area with high rainfall and population density. The purpose of this research is to determine the level of vulnerability and risk of landslides in Barus Jahe Sub-district in order to identify and minimize the risk of landslides using Geographic Information System (GIS). This research conducted landslide risk mapping in Barus Jahe Sub-district with reference to Permen PU No. 22/PRT/M/2007. The parameters used are slope, soil type, rock type, rainfall, land use, slope height, seismicity, population density, and housing. The parameters were then analyzed using scoring and overlay method to obtain landslide risk level class using QGIS software Version 3.28.4. The results of scoring and overlay were then validated using ROC curve. The results of scoring and overlaying show that the landslide risk level map in Barus Jahe Sub-district has 5 risk level classes, namely very low vulnerability class (0.358 km2), low vulnerability class (11.075 km2), medium vulnerability class (16.294 km2), high vulnerability class (40.202 km2), very high vulnerability class (32.918 km2). There is 1 village whose area is dominated by a very low risk level, namely Tangkidik Village. 4 villages with a dominance of low risk levels, namely Semangat Village, Barus Jahe Village, Sarimanis Village, Persadanta Village. 5 villages with a medium risk level dominance, namely Rumamis Village, Talimbaru Village, Bulan Julu Village, Bulan Jahe Village, Paribun Village. 4 villages have an area with a high risk level dominance, namely Pertumbuken Village, Serdang Village, Penampeng Village, Sikab Village, while 5 villages with a very high risk level dominance, namely Sinaman Village, Sukanalu Village, Sukajulu Village, Tanjung Barus Village, Barus Julu Village. And the results of the ROC curve obtained an AUC value of 0.842 or 84.2% which included a good classification. The results showed good prediction accuracy with an AUC value of 0.842 against the original conditions in Barus Jahe District.