A Data-Driven Approach to Landslide-Susceptibility Mapping in Mountainous Terrain: Case Study from the Northwest Himalayas, Pakistan

Abstract

This study develops a landslide susceptibility map using a data-driven approach and taking the district Muzaffarabad, northwest Himalayas, Pakistan, as a case study. The Muzaffarabad district was severely affected by the 25 Kashmir earthquake triggered landslides. To manage these landslides, it is necessary to collect data and information about landslides of the Muzaffarabad district. Therefore, a landslide inventory was prepared by using remote sensing imageries, and 459 landslides were identified. These landslides were divided into training and validation samples (7:3%). About 321 known landslide points were used as training sites in combination of nine causative factor rasters to produce a landslide susceptibility map of the area. About 2% of all training sites were verified through field mapping, and an accuracy of 77% was achieved. The selected causative layers include landcover, lithology, slope angle, elevation, distance to drainage, distance to faults, distance to roads, aspect, and slope curvature. The landslide susceptibility map was classified into low, moderate, high, and very high susceptible zones. The validity of the model was assessed with a success rate curve (SRC), whereas prediction efficiency was analyzed through a prediction rate curve (PRC). The validation results reveal fine compatibility between landslides and the obtained posterior probability model of the area. The efficiency of classification is 89%, and efficiency of prediction is 86.2%. To generate posterior probability, the cumulative area posterior probability (CAPP) curve was used to reclassify the continuous posterior probability scale map into four classes. According to the results of weights calculated through Arc-SDM, landcover, lithology, and slope angle are the three key parameters to determine the occurrences of landslides in the study area. To implement the landslide management strategies, the developed landslide susceptibility map can be used by the concerned agencies.