Calibration of Six Recursive Digital Filters for Baseflow Separation in East Java

Abstract

This paper shows the calibration process of base flow separation methods. Six (6) base flow separation methods were used for this study. The main input for this research was discharge data from 54 watersheds in East Java. Firstly, each method is calibrated using daily discharge data for each year (annually) to separate base flow. Then, optimal parameter values are obtained by averaging the annual values. Calibration process produces optimal parameters value for each watershed. Furthermore, validation is performed using optimal parameter values from watershed having complete discharge data to other watersheds. The average RMSE values range for all methods are: 0.30 to 0.38 for calibration process, and 0.27 to 0.36 for validation process. It appears that the parameters values from calibrated watersheds are transferable to validation watersheds on the same boundary of UPT.