GIS-based comparative study of information value and frequency ratio method for landslide hazard zonation in a part of mid-Himalaya in Himachal Pradesh

The road network of a developing country plays a vital role in its overall development. It is therefore important to ascertain landslide hazard assessment along a road network. Landslide hazard zonation focuses on preparing landslide hazard map by considering major instability factors causing the landslides. The present study deals with geographical information systems-based landslide hazard zonation of the study area. The study area comes under the mid-Himalayan region of Himachal Pradesh, India. The slope failures create major havoc every year due to high frequency of landslides along the road. Eight major landslide-causing factors have been identified for the study area, which includes slope, relative relief, curvature, aspect, drainage density, lithology, lineament density, and land use/land cover. Corresponding to each landslide causative factor, a layer has been prepared and landslide hazard zonation maps of the study area were evolved by using frequency ratio and information value methods. Approximately, 75% of the total landslides which occurred in the study area were used for training purpose, and remaining 25% were used for the validation of results using the area under curve technique. The developed landslide hazard zonation maps show satisfactory agreement with the landslide inventory of the study area. The success rate curve obtained for frequency ratio method is 77.18%, and for information value method, it is 74.76%. The validation of result illustrates that frequency ratio method is more accurate as compared to information value method for the study area. The present study shows that geographical information system provides a better environment for modelling of the statistical techniques, that is, frequency ratio and information value method in the present study.