Assessment of seismically-induced landslide susceptibility after the 2015 Gorkha earthquake, Nepal

The Gorkha earthquake (M_W 7.8) occurred on 25 April 2015 with its epicenter in the central part of the Gorkha District, Nepal. The earthquake triggered thousands of landslides in the central region of the Nepal Himalaya. Landslide-prone areas were identified by preparing earthquake-induced landslide susceptibility maps using a maximum entropy model. Thematic maps required for the model were prepared using geographical information system software. Of a total of 690 landslide locations, 50% were used for map generation and the remaining 50% for validation purposes. The final map was validated using the receiver operator curve method. The overall accuracy was 86.1% and using the validation data, the area under the curve was calculated as 91.1%. Jackknife analysis revealed that the terrain close to the rupture surface and around high shaking ground were the most important intrinsic and extrinsic parameters, respectively.