Spatial prediction of landslides in Pithoragarh district, Kumaon Himalaya, India
摘要
The Indian Himalayan region is prone to frequent and highly vulnerable landslides due to a combination of geo-environmental, anthropogenic, and climate-related factors. Pithoragarh district, located in the Kumaon Himalaya, exhibits a variety of factors ideal for landslides. The present study deals with the preparation of a landslide susceptibility zonation (LSZ) map of the Pithoragarh district using three statistical models. The thirteen causative factors such as slope angle, aspect, elevation, plan curvature, profile curvature, lithology, topographic wetness index (TWI), land use land cover (LULC), distance to road, distance to drainage, distance to thrust, soil texture, and rainfall were found to influence the landslide occurrences in the study area and subsequent thematic layers were prepared. Using Bhukosh inventory data and geographic information system (GIS) techniques, a landslide inventory map was created. One thousand six hundred twenty-five landslides have been divided into training dataset (70%) and testing dataset (30%). Consequently, three statistical, frequency ratio (FR), information value (IV), and weight of evidence (WoE), were utilized within a GIS platform to integrate essential influencing factors with the landslide inventory to generate LSZ maps. The LSZ maps categorized the study area into five different classes, such as very low, low, medium, high, and very high, according to the degree of landslide susceptibility. It was found from the LSZ maps that about 31.93–37.84% (31.93% in the FR, 36.854% in the WoE, and 37.841% in the IV-based LSZ map) of the Pithoragarh district falls under very high and high landslide susceptibility zones. Based on the area under the curve value, the IV model was found to provide a higher success rate and prediction rate than the other two employed models.