Studi Pendahuluan Pemisahan Aliran Dasar Menggunakan Metode Grafis dan Metode RDF

Abstract

This research aimed to estimate the baseflow separation at severals watersheds in UPT PSDA Pasuruan (East of East Java, Indonesia). Two graphical method of baseflow separation (fixed interval method and local minimum method) and Eckhardt filter were compared to separated baseflow from total flow. Eckhardt filter was one of the recursive digital filter (RDF) method of baseflow separation. Methodology consist of : (1) data inventoring (2) data processing, (3) calibrating and validating, and (4) evaluating of models performances. Daily discharge were used as main input for the analysis. Then, each method used to separate the baseflow from the total daily discharge. Furthermore, each algorithm was calibrate using daily discharge data for each year. The mean values of parameters obtained were used to separate baseflow for whole periode of record RMSE, R Squared (R2), and FDC used to evaluate the model performance during dry periode in Juli to September (asumsing that for this period no rainfall have occurred). Calibration were conducted on each the wathershed using the same procedure. Validation was conducted only from watershed with complete data (Kadalpang Bangil watershed). The results showed that ekhardt filter perform better then other algorithms