ANALYSIS OF THE SPATIO-TEMPORAL FLUCTUATION IN STORAGE CAPACITY OF THE HIRAKUD RESERVOIR USING GOOGLE EARTH ENGINE

Abstract

Reservoirs are the pools of water created to store and control water flow. The storage capacity of a reservoir has a fundamental impact on life. Observing surface water body size and volume changes can determine the area's ecology. So, to monitor the reservoir’s life, it is necessary to evaluate storage frequently. The reservoir's storage capacity is affected by parameters like sedimentation accumulation rate, changes in climate extremes over this age, changes in land use, and land cover patterns in the upstream section of the reservoir. The conventional and absolute method for this assessment is a bathymetric survey of the land profile under submergence. It needs a lot of resources and advanced equipment. So, to overcome this, remote sensing and GIS techniques were adapted to perform such analysis using high-resolution surface reflectance images. Water extraction indices proposed by researchers were used to separate into water and non-water pixels at different thresholds, which implies the water coverage of the reservoir at the date of the satellite overpass. To incorporate a temporal change in the reservoir’s capacity, a series of images were used to analyze the increasing water levels from MDDL to FRL, i.e., from dry to monsoon seasons. This study helps in modifying and amending the rule book of the Hirakud reservoir according to the current scenario of storage capacity.