Analisis Potensi Air Baku Menggunakan Model Swat Di Sungai Cipunagara Untuk Kabupaten Indramayu Dan Kabupaten Subang

Abstract

Population growth in Indramayu and Subang Regency increase significantly from 2010-2020. It will cause an increase in demand for raw water. Therefore, this study aims to determine raw water demand in Indramayu and Subang Regencies by comparing the availability of water in the Cipunagara River with the water needs there. Streamflow analysis at the Cipunagara River at the Kiarapayung station outlet was analysed for four years, from 2012 to 2015. The SWAT modelling requires land use data, soil properties, climatological data, and discharge measurement data. There are four steps for creating the SWAT model, which consists of watershed delineation, HRU formation, model simulation, then calibration and validation processes. The discharge from the SWAT output will be used to calculate the availability of raw water for the Cipunagara River with a reliable discharge of 80%. Then the discharge compared with raw water demand in Indramayu Regency for 2032. The results of the SWAT modelling analysis on the Cipunagara Watershed showed a correlation value (R) of 0.65 and a Nash-Sutcliffe Model Efficiency (NS) of 0.40, which means the model was acceptable for predicting river discharge. The results of calculating the reliable discharge using simulated discharge have a maximum value of 79,584 m3/second in December and a minimum discharge of 4,625 m3/second in October. It is concluded that these results meet the raw water needs in Indramayu Regency in the 2032 plan year discharge value of 2,604 m3 /second.