Reservoir water budget estimation using satellite and ground measurement data

Abstract

Rising air temperatures, increased rainy runoff, reduced dry season runoff, and severe weather conditions have intensified floods and droughts, significantly affecting the reservoir water supply. The accuracy of reservoir water balance is crucial for meeting water needs. The study compares satellite data and ground measurements to analyze the water budget of Sutami Reservoir in Indonesia. Satellite data collected included precipitation (Tropical Rainfall Measuring Mission-TRMM) and evaporation (Global Land Data Assimilation System-GLDAS). The water balance approach was utilized to analyze the water budget. The suitability tests used were Root Mean Square Error (RMSE), Nash-Sutcliffe Efficiency (NSE), Correlation Coefficient (CC), and Relative Error (RE). The study revealed that the data from TRMM and GLDAS satellites closely resembled ground measurements. The reservoir water balance analysis revealed that satellite data aligns with ground measurements, indicating water shortages in the dry season and excess water in the rainy season. Satellite data is particularly beneficial for watershed management in areas lacking ground measurement equipment, as it can be analyzed for various purposes.