Fretful Longevity of Upper Kolab Reservoir, Odisha by GIS Study

Abstract

Background: The nonrenewable energy source, hydropower reservoirs are the yardstick that scales up developing countries around the globe including India. The multipurpose Upper Kolab project is housed at the Kondhan Hills of the north Eastern Ghats mobile Belt range near Koraput Town. The dam is of length 630.5m with a height of 54.50m, and an average annual flow1803 M cum in operation since 1986. The project was built for 320MW generation, about 445000Ha CCA, and water supply to nearby towns. Objective: Climate Change and anthropogenic stresses have resulted in depleting the major reservoir’s capacity by sedimentation, hence irrigation and power generation. The southern part of the Northeastern Ghats belt is worst affected. The present study is about the rate of capacity loss of Upper Kolab Reservoir in south Odisha. Methodology: The present study involves the collection of data from the Landsat 4, Landsat 5, and Landsat 8  OLI Operational land user image of 30 m resolution was downloaded from either SRTM data or Earth Explorer data, and the digital elevation model (DEM) was prepared for the same period of the years 1996, 2002, 2013, 2017 and 2021. The TOPO geological map (1:500,000 scale) of 1983 was used to digitize geological formations. The ArcGIS 10.2 software is used for the topographic constraints of the water body and its watershed. The maps generated are slope maps, aspect maps, and various differentials sediment values in volume and water spread area. Results and Conclusion: The inference is the fast rate of annual sedimentation @3.542mm/yr which is much higher than its mother basin Godavari (@2.22mm/yr. The longevity of the Upper Kolab Reservoir and power generation shall be affected earlier before it is designed life. Sedimentation needs prioritization, as caused by the anthropogenic and climate-induced huge sediment entry to the upper Kolab reservoir warranting a secondary reservoir downstream.