Abstract. The Karakoram Highway (KKH) is an important route,
which connects northern Pakistan with Western China. Presence of steep
slopes, active faults and seismic zones, sheared rock mass, and torrential
rainfall make the study area a unique geohazards laboratory. Since its
construction, landslides constitute an appreciable threat, having blocked the
KKH several times. Therefore, landslide susceptibility mapping was carried
out in this study to support highway authorities in maintaining smooth and
hazard-free travelling. Geological and geomorphological data were collected
and processed using a geographic information system (GIS) environment.
Different conditioning and triggering factors for landslide occurrences were
considered for preparation of the susceptibility map. These factors include
lithology, seismicity, rainfall intensity, faults, elevation, slope angle,
aspect, curvature, land cover and hydrology. According to spatial and
statistical analyses, active faults, seismicity and slope angle mainly
control the spatial distribution of landslides. Each controlling parameter
was assigned a numerical weight by utilizing the analytic hierarchy process
(AHP) method. Additionally, the weighted overlay method (WOL) was employed to
determine landslide susceptibility indices. As a result, the landslide
susceptibility map was produced. In the map, the KKH was subdivided into four
different susceptibility zones. Some sections of the highway fall into high
to very high susceptibility zones. According to results, active faults, slope
gradient, seismicity and lithology have a strong influence on landslide
events. Credibility of the map was validated by landslide density analysis
(LDA) and receiver operator characteristics (ROC), yielding a predictive
accuracy of 72 %, which is rated as satisfactory by previous researchers.
Flood Susceptibility Analysis using Geographic Information System, Frequency Ratio and Relative Frequency Ratio Methods in San Pa Tong District, Chiang Mai, Thailand
