Analytical hierarchy process (AHP) based landslide susceptibility mapping of Lish river basin of eastern Darjeeling Himalaya, India

Abstract

Landslide is one of the most destructive natural hazards of Darjeeling Himalaya. In the present study, analytical hierarchy process (AHP) has been applied to develop landslide susceptibility map of the Lish river basin of Eastern Darjiling Himalaya based on geospatial tools. A total of 188 landslide location points of very small to large polygon coverage were identified with the help of GPS study, SOI (Survey of India) topo-sheets and Digital Globe Quick Bird image to prepare a landslide inventory map. 70% training data sets of the landslide inventory was applied for training analytical hierarchy process (AHP) model and remaining 30% data sets were used for validation of the landslide susceptibility map. ERDAS IMAGINE, ASTER GDEM image, Arc GIS and PCI Geomatica software, topographical map, Landsat TM and 8 OLI satellite image, google earth image, soil map (NBSS and LUP Regional Centre), geomorphology and lithology (NATMO and GSI) were used and processed to prepare seventeen causative factors i.e. slope angle, slope aspect, slope curvature, altitude, relative relief, geomorphology, geology, distance to lineaments, lineament density, soil, LAND USE & land cover, NDVI, drainage density, distance o drainage, stream power index, topographic wetness index, and rainfall. Factor weights and class weights of all the data layers were derived using AHP and then weighted data layers were integrated to generate the landslide susceptibility map. To validate the result, success rate curve was made with the help of landslide susceptibility and cumulative percentage of landslide occurrence which showed the accuracy level of 89.72%.