19. Investigation and Analysis of Geohazards Induced by the 2015 Nepal Earthquake Based on Remote Sensing Method

The devastating earthquake that occurred in Nepal on April 25, 2015, caused widespread damage and ravaged rural communities and economy. It triggered numerous geohazards in the steep mountains and hills throughout the impact zone, including catastrophic landslides in the Langtang Valley. Potentially, these landslides can have devastating effects on humans, destroy infrastructure, obstruct river flows and cause outburst floods. In order to understand the effects of the earthquake-induced geohazards and their risk assessment, number of scientists have carried out numerous geohazard investigations using remote sensing approach. This paper presents evaluation results based on the study of earthquake-related geohazards. Later, three main geohazards related to the Langtang avalanche, landslide dam and glacial lake monitoring are discussed in detail. Finally, the zones around the two China–Nepal roads are selected as the study areas. A change detection method is applied to identify the geohazards occurred in these areas and to understand their spatial distribution pattern. The study offers awareness about the earthquake-induced geohazards in Nepal. Landslide is identified as the major geohazard induced by earthquake, and its regional impact will continue in near future.