Landslide Susceptibility Mapping along NH-7 in the Himalayas using Frequency Ratio Method

The main aim of this study is the evaluation of landslide susceptibility along NH-7 from Karnaprayag to Joshimath, Uttarakhand by employing the frequency ratio method in the GIS environment. For the analysis of landslide vulnerability, 83 landslide points were identified. Sixteen layers of landslide causative elements were prepared, including slope angle, soil, slope aspect, seismicity, elevation, proximity to road, proximity to faults, lithology, proximity to stream, topographic wetness index (TWI), rainfall, normalized difference vegetation index (NDVI), plan curvature, land use and land cover (LULC), stream power index (SPI) and profile curvature. An inventory map of landslide events was generated. Further, for the assessment of landslide susceptibility, the evaluation of frequency ratio for each conditioning factor was assessed. The model was validated using ROC(AUC) curves. The value for success rate curve (SRC) is 85.5%, while for the prediction rate curve (PRC) is 84.1%. The model is in good agreement with the distribution characteristics of past landslides in the study area. Land-use planners and decision-makers may utilize the results to manage and mitigate potential landslides, safeguarding the ecology and preserving society.