Analysis using the F. J. Mock Method for calculation of water balance in the Upper Konto Sub-Watershed
Dian Chandrasasi, Lily Montarcih Limantara, Riska Wulan Juni
Abstract
Abstract A study of water balance in the Upper Konto sub-watershed was carried out to determine the potential for water availability and its use in the multisector water needs. Rainfall was converted into discharge using the F. J. Mock method, compared with the observed discharge, and calibrated with the Relative Error, Root-Mean-Square Error (RMSE), Nash-Sutcliffe Efficiency (NSE), and Correlation Coefficient (R). The potential for water availability was calculated based on an 80% dependable flow using the Weibull probability method with an amount of 22.41 m 3 /sec, equivalent to 706.622 million m 3 /year. The amount of water demand within a period of 25 years in scenario 1 (calculated based on data and increasing according to the growth rate) is 95.090 million m3/year, while in scenario 2 (based on the assumption that domestic, non-domestic, and industry demand increased while fishery, agriculture, and livestock demand remained constant) is 93.419 million m 3 /year. The results of the water balance analysis showed that the potential for water availability is sufficient for all multisector water needs, or indicates a surplus condition for 25 years (2017-2042).