Landslide Hazard Assessment Using Probabilistic and Statistical Approaches: A Case Study of Chamba Region, Himachal Pradesh, India

Abstract Landslides have adversely affected the southern region of Chamba district during past three decades. To minimize the damage to ecology and environment due to such natural calamities, landslide hazard zonation and mitigation measures are essential component to stabilize the natural slopes and other physiographic features. In order to remodeling lopsidedness in study area analytical hierarchy process and information value methods with applications of remote sensing and geographic information system (GIS) are utilized to delineate the most recumbent landslide hazard zones. Eleven-factor maps like slope gradient, slope aspect, relative relief, land use/ cover etc., were delineated using different sets of data like satellite images and field investigations etc. Depending upon the severity, landslide hazard maps (LHZ) were further divided based upon information value method and analytical hierarchy process models respectively, into five different categories very low (1.2% and 2.95%), low (5.31% and 4.27%), moderate (24.40% and 20.03%), high (29.26% and 31.03%), and very high (40.30% and 44.2%). These hazard maps obtained through both information value and analytical hierarchy process (AHP) were compared for accuracy using success rate curve (SRC) method. Accuracy of the hazard zonation maps was found to be 78.62% for AHP and 85.17% for Inf. Value models.