Aerial Expansion of Govind Sagar Lake in Recent Decades of Bilaspur District of Himachal Pradesh

Abstract

A large number of glacial lakes have appeared in many mountain areas of the world due to global warming. Severe floods have been caused by frequent outbursts from the glacial lakes. Hence, investigation is necessary for the management point of view; thereby, satellite images, geological survey and meteorological data are best options for identification of change detection of such lakes. Govind Sagar Lake situated in the foothill of Himalayas in the state of Himachal Pradesh, India, is one such lake where investigation is needed. The present study assesses the aerial expansion of the lake since last few decades including identifying the hidden cause of its expansion. The satellite images clearly suggest the increase in water spread area in the lake for different years. In an attempt to gauge the causes of expansion, the authors attempt to analyze the trend of the climatic variables, viz., rainfall and temperature. Annual and monthly precipitation trends were detected with Mann-Kendall and Sen’s Slope statistical test. The precipitation and temperature trend suggest lesser role in the aerial expansion; rather, large-scale silt deposit into the lake is the main cause for the expansion including extra source of inflow of water into the lake.