Landslide susceptibility modelling in Cianjur Regency using landslide numerical risk factor

Cianjur Regency was often hit by landslides. In 2022, this regency was affected by landslide, leading to several civilian deaths, injuries, along with damaged houses and infrastructure. To minimize the impact, determining landslide susceptibility level was proven to be an essential step in maximally plan- ning disaster management. Therefore, this study aimed to develop landslide susceptibility model in Cianjur Regency using the Geographic Information System (GIS). The landslide susceptibility model was based on Landslide Numerical Risk Factor (LNRF) method using spatial data consisting of historical landslides, the Digital Elevation Model (DEM), geology, soil types, land cover, rainfall, and earthquakes in Cianjur Regency. The accuracy of model was tested using the ROC-Curve method with a value of 0.845 being considered very good. The result showed that most of areas in Cianjur Regency had moderate and high levels of landslide susceptibility, with a percentage of 40% and 46%, respectively. Areas with high level were mostly found in the southeastern part of Cianjur Regency, moderate was evenly distributed, while low levels were in the northeastern and coastal areas.