Effects of topographic datasets on physically based landslide model at a hyper local slope

This study conduct simulation of small (hyper local) rainfall induced landslide event to get a better understanding of the event's mechanism and check its factors for developing more sustainable spatial plan. The issue is important because some report showed that small (hyper local) landslides are insignificant in size, but cause heavy damages and fatalities. This study uses three kinds of topographic data set for simulating the hyper local terrain; 8-meters resolution Digital Elevation Model (arcDEM), GPS-RTK based Digital Terrain Model (rtkDTM), and Unmanned Aerial Vehicle based Digital Surface Model (uavDSM). Accumulated antecedent rainfall intensity also considered as an input beside the physical limits of soil for slope stability modeling (SHALSTAB). Comparison between all topographic datasets suggest that rtkDTM with 2-meters resolution considered as the best option as an input for simulating the hyper local landslide, compared to other two. The results also suggest that the rainfall threshold for surroundings of the study area should not exceed total accumulated antecedent rainfall intensities, 410 mm in 14 Days. The use of high accuracy and precision three-dimensional ground control points (3D GCPs) are important to increase the aerial mapping quality. Furthermore, the terrain evaluation for more sustainable spatial development plan and better early warning system in the future needs to be done. In short, higher resolutions and quality of topographic data sets are considered valuable investments for landslide hazard prevention in developing areas.