Studi Pendahuluan Pemisahan Baseflow: Studi Kasus 6 Metode RDF (Recursive Digital Filter) di Wilayah UPT PSDA Pasuruan, Jawa Timur

Abstract

This research dealt with estimation of baseflow contribution at severals watersheds in the area of UPT PSDA Pasuruan (East Java, Indonesia). Six Recursive Digital Filter (RDF) methods were used to separate baseflow from total flow. Methodology consist of : (1) data inventoring (2) data processing, (3) calibrating and validating, and (4) evaluating models performances. Daily discharge were used as main input for the analysis. Then, each recursive digital filter output was used to separate baseflow from the total daily discharge. Furthermore, each algorithm was calibrate using daily discharge data for each year. The mean values of parameters obtained used to separate baseflow for whole periode of record. RMSE, Scatter plot and FDC used to evaluate the model performance during dry periode in Juli to September (assuming that for this period no rainfall have occurred). Calibration were conducted on each watershed using the same procedure. Validation was conducted only from watershed with complete data (Pekalen watershed). The results showed that two filters (EWMA and Lynie Hollick) perform better then others algorithms.