STUDI PENDAHULUAN PEMISAHAN BASEFLOW: STUDI KASUS 6 METODE RDF (RECURSIVE DIGITAL FILTER) DI

Abstract

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