Water level retrieval and water body mapping: A case study of nagarjuna sagar reservoir

Abstract

Satellite radar altimetry is exclusively designed for the oceanographic studies such as wind speed, sea surface level, tide height, and volumetric changes. In spite of the fact that the satellite radar altimetry is predominantly intended for oceanographic studies and ice sheet monitoring these days, the utilization of altimetry information is reached out to think about water dimension of inland water bodies like reservoirs, rivers and so on. This study covers the use of SENTINEL-3 Ku/C Radar Altimeter (SRAL) for the monitoring water level of Nagarjuna Sagar reservoir located in Telangana state, India. Satellite altimetry works on the principle of range measurement that is the measure of the travel time of microwave pulse from emission to receiving which is interrupted by many atmospheric conditions which cause a disturbance in travel time of microwave pulse which is to be adjusted to get corrected depth of water level. The SRAL information is handled utilizing Broadview Radar Altimetry Toolbox (BRAT) programming. The consistency of derived water level is compared using field data, and all the depths are within error range of one meter. Water body mapping is carried out utilizing cloud-free data of Landsat-8 from January 2016 to March 2019 which showed a gradual decrease in water level from November to May. © Springer Nature Singapore Pte Ltd 2021.