Comparison of the application of HBV and HEC-HMS hydrology models for accessing climate change in the upper Citarum Watershed, Indonesia

Abstract

Hydrologically, the upper Citarum watershed was critically damaged. This study propose to compare HBV and HEC-HMS model performance for estimating discharge in upper Citarum watershed. Besides, this study wants to know changes in discharge in the future as a result of climate changes. Discharge simulation was carried out with the HBV and HEC HMS models in the period 2006-2007 as calibration and 2008 as validation. Meanwhile, future discharge changes are calculated in 2045 based on climate model projections output from CORDEX namely MPI, CNRM, EcEarth, and CSIRO. Model performance is calculated based on the value of statistical bias, NSE, and correlation. The results showed that HEC-HMS model has bias, NSE, and corellation value of 6.33, 0.57, and 0.8. Whereas, the HBV values are 3.67, 0.61, and 0.76. Therefore, based on NSE and bias value, the HBV model performs slightly better than the HEC-HMS in upper Citarum watershed. There are an increase in the daily discharge by RCP4.5 scenario. In contrast, the daily discharge by RCP8.5 decreased in upper Citarum.