Landslide susceptibility mapping by using a geographic information system (GIS) along the China–Pakistan Economic Corridor (Karakoram Highway), Pakistan

摘要

The Karakoram Highway (KKH) is an important route,which connects northern Pakistan with Western China. Presence of steepslopes, active faults and seismic zones, sheared rock mass, and torrentialrainfall make the study area a unique geohazards laboratory. Since itsconstruction, landslides constitute an appreciable threat, having blocked theKKH several times. Therefore, landslide susceptibility mapping was carriedout in this study to support highway authorities in maintaining smooth andhazard-free travelling. Geological and geomorphological data were collectedand processed using a geographic information system (GIS) environment.Different conditioning and triggering factors for landslide occurrences wereconsidered for preparation of the susceptibility map. These factors includelithology, seismicity, rainfall intensity, faults, elevation, slope angle,aspect, curvature, land cover and hydrology. According to spatial andstatistical analyses, active faults, seismicity and slope angle mainlycontrol the spatial distribution of landslides. Each controlling parameterwas assigned a numerical weight by utilizing the analytic hierarchy process(AHP) method. Additionally, the weighted overlay method (WOL) was employed todetermine landslide susceptibility indices. As a result, the landslidesusceptibility map was produced. In the map, the KKH was subdivided into fourdifferent susceptibility zones. Some sections of the highway fall into highto very high susceptibility zones. According to results, active faults, slopegradient, seismicity and lithology have a strong influence on landslideevents. Credibility of the map was validated by landslide density analysis(LDA) and receiver operator characteristics (ROC), yielding a predictiveaccuracy of 72 %, which is rated as satisfactory by previous researchers.