Studi Geomorfologi dan Analisis Bahaya Longsor di Kabupaten Agam, Sumatera Barat

Abstract

Sumatra is an active tectonic-volcanic island located in the collision of Indo-Australian and Eurasian plates. The movement of the plates often caused natural disasters and one of which led to landslide. Landslides are one of geomorphic processes which often times generating a disaster in Sumatra. Agam Regency is one of the administrative areas in Sumatra where the landslides have frequently been taken place. This research aims to (1) learned geomorphological condition of Agam Regency and (2) to assess landslides susceptibility and hazard. The methods of assessment used were Multi-Criteria Evaluation (MCE) and the parameters comprise slopes, lithology, precipitation, soil, and land cover/land use. Those parameters were analyzed by geographical information system (GIS) technique using score and weighting. Ground checked has been hold for validating tentative result of analysis and collecting primary data. The result showed that the geomorphology of Agam Regency characterized by the plain area in western part and hilly/mountainous area in the middle and eastern parts (the so called Bukit Barisan Mountain). Based on landslides susceptibility analysis, it indicates that 54.3 % of Agam Regency classified as safe area (1211.5 km²) and conversely 18.6 % as severely susceptible area (414.7 km²). According to landslides hazard analysis, it shows that 51.3 % of Agam Regency classified as safe area (1146.7 km²) and contrarily 13.6 % as severely hazard area (303,6km²). Geomorphologically, all severe class of landslides susceptibility and hazard areas situated in the hilly/mountainous areas possessing slopes steepness of 15 % to > 40 %.