Landslide susceptibility mapping using sinmap method in a small hilly area: case study in Cibanteng Village, West Java

Abstract

This paper presents the results of landslide susceptibility mapping in small hilly areas, Cibanteng village, Cianjur district, West Java. In this study. the physically-based model SINMAP (Stability Index Mapping) was applied in the GIS platform. The SINMAP model simulation requires data of physical properties of soil, such as cohesion value, internal friction angle, and soil hydrology to calculate the value of factor of safety (FS). The values of cohesion and fraction angel for the 10 sample points were obtained from the laboratory test results, while the value of soil hydrology, i.e hydraulic conductivity, transmissivity, effective rainfall and index wetness, referred to the literature source. The DEM (digital elevation model) was generated from the 1:25,000 digital topographic map, which produced the soil slopes and specific upstream contributing areas. The result of SINMAP model simulation shown that the regions with a high landslide susceptibility (FS <1, unstable) were spread unevenly with an area of 261ha (17,6% of the study area). The Landslide susceptibility map from the SINMAP model provided a satisfactory result with an accuracy of 62,5% against to the landslide events occurred during the period 2010-2017.