Assessing the performance of a novel HBV model: a comparative analysis with existing HBV-Light model and climate projections

2023-9-11
Yılmaz, Sena
Climate change and water resource investigations frequently use surface runoff as a key hydrometeorological metric. To meet these investigation objectives, an open-source hydrological model is necessary, where currently only a limited number of models are available. The main goal of this study is to create an open-source, new, and simple hydrological model called the HBV-R. To compare the performance of HBV-R, the benchmark model HBV-Light, which has no open-source code, is utilized. This study is performed over the Çoruh Basin of Türkiye, known for having significant hydropower potential. The HBV conceptual hydrological model is calibrated and validated using runoff observations from 30 different ground stations between 1980 and 2005. TRMM 3B42 and ERA5-Land precipitation data are used as forcing datasets in different simulations. To investigate the impact of climate change on the water resources potential of Çoruh Basin, precipitation and temperature projections originating from global climate model datasets HadGEM2-ES, MPI-ESM-MR, and GFDL-ESM2M under the RCP 4.5 and RCP 8.5 emission scenarios are used after being bias-corrected by QDM method. A comparative analysis of HBV-Light and HBV-R models reveals mean NSE values of 0.51 and 0.61, respectively, validating daily simulations across thirty sub-basins. HBV-Light predicts a decline in surface runoff potential by approximately 3% (RCP 4.5) and 8% (RCP 8.5) from 2023 to 2098. Conversely, HBV-R projects an increase in surface runoff potential, estimating a rise of 20% (RCP 4.5) and 13% (RCP 8.5) during the same period. Results show the high potential of HBV-R in hydrological modeling and prediction.