SARAL/AltiKa Altimetry Data for Monitoring of Inland Water Body: a Case Study of Mayurakshi Reservoir, India

摘要

Present study aims at monitoring of water levels for Mayurakshi reservoir (similar to 68 sq. km) located in the Jharkhand state, India using Geophysical Data Records (GDR) data from SARAL/AltiKa launched in February, 2013. Reservoir water levels for the period April, 2013 to December 2014 were derived from space using SARAL/AltiKa data. The absolute average difference, standard deviation and the Root Mean Square Error (RMSE) between altimetric data and gauge readings were 0.49, 0.29 and 0.56 m respectively. The accuracy of the relative water levels ranges between 0.008 and 0.8 m with a mean of 0.34 m, standard deviation of 0.27 m and RMSE of 0.44 m. Resulting time series of relative height changes and the amplitude variations are identical for most of the study period except during low stage, linked to the fact that some reservoir waveforms are season dependent. The results highlight the applicability of the SARAL/AltiKa data for monitoring small to medium reservoirs having surface area less than 100 sq. km.