Satellite based Analysis of Artificial Reservoir induced Landslides in Data Scarce environment: A case study of Baglihar Reservoir in India

The monitoring of Reservoir induced landslides is very important for assessing and mitigating the associated geo-environmental hazards. This research utilizes Persistent Scatterer Interferometry technique for the mapping and monitoring of Reservoir Induced Landslides in the rim area of Baglihar Dam Reservoir on Chenab river (Jammu and Kashmir, India) along National Highway NH-244. It has been evident that the slope movements are necessarily impacted by the reservoir drawdown effect (RDE) as well as the rainfall. The monitoring of such landslides becomes very important as it endangers the dam safety and reduces the capacity of the reservoir as well as it poses risk to agricultural fields and roads on the rim. In our case it is more important as the dam had been a hot issue between India and Pakistan. This area lacks in-situ data (it is a backward area as well as had been victim of insurgency) as well as some data is classified owing to the international sensitivity. Sentinel-1 C-band Satellite Radar data of both ascending and descending tracks are used. The monitoring results have yielded the Line of Sight (ascending) slope movement along the reservoir rim varies from -95.1 mm/year to +85.1 mm/year. LoS velocity obtained by both the tracks has been resolved to give an estimate of vertical as well as East-West direction velocity. The temporal correlation between the displacements and the local precipitation was qualitatively analyzed. Precipitation CHIRPS data was retrieved from Google Earth Engine. Two major slopes has been monitored for the land movement one on north bank another on south bank. We have also detected slope instability in the nearby town of Batote. The retrieved estimates agrees with the field observations.