Nepal is susceptible to many disasters with landslides being one of the most prominent ones among them especially in hilly and mountainous regions. Landslide hazards cause not only the destruction of physical infrastructures but also cause loss of human lives. There has been a surge in landslide events in the last decade which could be attributed to Mw 7.8 Gorkha Earthquake 2015. Palungtar municipality also lies in one of the affected districts Gorkha and suffers from landslide hazards due to its topography. Preparation of landslide susceptibility map can be taken as the initial step for landslide mitigation and minimization of the loss caused by landslide hazards. In this study, the landslide susceptibility of Palungtar municipality was assessed using three susceptibility models namely Heuristic model, Information Value model, and Analytical Hierarchy Process model. There were 70 landslide sites identified using Google Earth and Field visit. Eleven parameters namely slope, aspect, land use land cover, geology, plan curvature, profile curvature, distance from road, distance from river, Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI) and Topographic Wetness Index (TWI) were considered for landslide study. Geographic information system (GIS) was used for the spatial analysis of data and preparation of susceptibility maps. All of the landslide susceptibility models were divided into three categories (low, medium and high). Landslide susceptibility models by Heuristic method, Information Value Method and Analytical Hierarchy Process (AHP) method categorized 13.13%, 10.38 % and 11.4 % of the study area as highly landslide susceptible zone respectively. Validation is crucial for checking the accuracy of landslide susceptibility models. The Area under the Receivers Operator Characteristic (ROC) Curve (AUC) was generated for validation of the landslide susceptibility models which was found to be 0.825, 0.927 and 0.846 for Heuristic model, Information Value model and Analytical Hierarchy Process model respectively. The AUC curve indicated that the Information Value method had a greater prediction rate than Heuristic and AHP method for Palungtar municipality. 37 infrastructures among which 21 infrastructures considered as critical and 16 considered as utility infrastructures were exposed to landslide hazards. The landslide susceptibility map is expected for the efficient infrastructure planning of the municipality. These maps will be helpful for the preparation of mitigation plans.

Keywords

Landslide susceptibility, Analytical Hierarchy Process (AHP), Information value method, Heuristic method, Area under Curve (AUC)

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