Set Up and Calibration of a Spatial Tool for Simulating Latest Decades’ Flow Discharges of the Western Java: Preliminary Results and Assessments

This paper discusses a study of application of global spatio-temporal climate data sets and a hydrological model operated in Spatial Tools for River Basin Environmental Analysis and Management (STREAM). The study investigates reconstruction of monthly hydrographs across several selected points of the western part of Java, Indonesia for the period 1983-2002. Prior to the reconstruction, set up and calibration are carried out. The set up includes preparation of monthly precipitation and temperature data set, digital elevation model of the domain being studied and their compilation with land cover map. Discharge observations from six stations located mostly at the upper parts of major watersheds in the domain are used to calibrate the model. It is found that the model performs results with acceptable agreement. Comparison between computed and observed monthly average discharges correlate quite well with coefficient ranging from 0.72 to 0.93. The accuracy of computed total annual average discharge in five out of six observation stations is within the range of 7%. Optimum setting of calibration parameters is discovered. This study offers scheme for reconstructing historical discharge in paleo-climate perspective and future scenario for predicting local effect of global climate change, given the predicted climate data sets and geographic setting (i.e. topography and land cover)