Landslide Susceptibility Mapping of Phewa Watershed, Kaski, Nepal

Abstract The objective of this study was to assess the quantities of association between landslide events and causal factors in order to generate an accurate, updated landslide susceptibility map (LSM) of the Phewa watershed in Kaski, Gandaki District, Nepal. Landslides are the second-largest natural disasters of the world, and the costs of their damage could be more than those of all other multi-hazard disasters together. Nepal receives a lot of rain, especially during the monsoon season, which creates a number of water-induced risks each year, such as landslides. The LSM, which allows for effective landslide risk prediction. The most dependable and popular statistical approach for determining LSMs is the frequency ratio (FR) model. In ArcGIS 10.8, the LSM was created using eight causal factors. Five classes were represented in the LSM, with the low class having a large percentage (43.226%) and the high class having a low percentage (0.63%). In FR techniques, slope, proximity to a stream or road, land use/cover, precipitation, and proximity to a road are given greater weight than aspect, profile curvature, and plan curvature, which are given comparably less weight in this study area. Using the area under the curve (AUC), the model's performance was validated, and the performance was good, 0.71. The information given by this LSM, which provided the spatial distribution of the landslide and help to reduce landslide risk issues in the Phewa watershed, can be useful to researchers, communities, planners, and the government.