Geomorphological Characteristic of Landslide Hazard Zones in Sukarame Village, Cisolok Subdistric, Sukabumi Regency

Abstract

Geomorphology is the study of landforms, the processes of its formation, and the relations between forms and processes in their spatial order. Landslide is the movement of a mass of rock or earth from a higher place to a lower level due to the interaction of the geology structures, hydrology, and geomorphology. In a geomorphological unit, various aspects actively control the occurrence of ground movements. Knowing the geomorphological characteristics is crucial to identify a large estimation of the potential for landslides in the region. The Village of Sukarame is one of the villages in the Sukabumi Regency located on the slopes of Mount Halimun, whose territory is divided into west and east, separated by the Cisukarame River. Mapping the required geomorphological units Digital Data Elevation Model Indonesia (DEMNas) from the Geospatial Information Agency (BIG) is processed for altitude and slope data, as well as geological data and river data collected from BIG. Verification of landslide events through interviews and field surveys geomorphological unit analysis is done by overlaying and comparing the results of field observations. Also, a descriptive analysis is conducted by observing the map of landslide hazards zone from INARisk. The results show that the Village of Sukarame materialized from volcanic and fluvial origins. It has nine geomorphological units, which are the Hill Intrusion, Floodplain, Tapos Breccia Volcanic Plain, Citorek Tuff Volcanic Plain, Halimun Lava Slope, Tapos Breccia Slope, Citorek Tuff Slope, Fumaroles Plain, and Halimun Lava Field. Landslide-prone areas in Sukarame are in the geomorphological unit of Hill Intrusion, east of Halimun Lava Slope, Citorek Tuff Volcanic Plain, and along the river cliffs of the Cisukarame River and Cimaja River. The landslides occur naturally on the river cliffs of Floodplain and the cliffs of Citorek Tuff Volcanic Plain, which are dominated by sediments that cause the soil surface to become unstable. Moreover, anthropogenic activities, such as mining in the Hill Intrusion, also affect landslide occurrence in Sukarame.