Land Use Dynamics and Impact on Regional Climate Post-Tehri Dam in the Bhilangana Basin, Garhwal Himalaya

Abstract

Land use and land cover (LULC) changes are a dynamic process determined by natural factors as well as the degree of human interaction in spatial and temporal perspectives. The present study focuses on analysing the LULC changes in the Bhilangana basin post-Tehri dam construction in the Garhwal Himalaya. Landsat series satellite images were used for three time periods to quantify spatial and temporal changes in the LULC using unsupervised classification techniques. The calculations of the areal coverage and change detection were carried out using the ArcGIS 10.3 software. The study finds that LULC changes were observed in the area surrounding the Tehri reservoir. The area under forest cover decreased by 54.71 km2, which is −5.7% of the geographical area, followed by agricultural land by 6.06 km2 (−0.4%) and scrubland and grass cover by 4.23 km2 (−0.28%) during the decade 2000 to 2010. Gradually, due to compensatory afforestation, forest cover increased by 5.65% in the period 2010–2020. A significant relationship with climatic variability is also established with LULC change in the region. The presence of a large water surface at a high altitude modified the albedo and air temperature and increased the atmospheric humidity and precipitation pattern. This study would be vital in understanding the climatic variability in the Himalayas and its impact on the community, environment and climate.