Impact of climate change on water quality in the Upper Dong Nai River Basin, Vietnam

Khoi Dao

Thursday 2 july 2015

9:00 - 9:15h at Central America (level 0)

Themes: (T) Water resources and hydro informatics (WRHI), (ST) Catchment hydrology

Parallel session: 10H. Water resources - Catchment

The Upper Dong Nai River Basin was studied to quantify the potential impact of climate change on the water quality (TSS, T-N, and T-P) using a multi-model ensemble approach. Climate change scenarios (RCP4.5 and RCP8.5) were developed from an ensemble of GCMs (General Circulation Models) obtained from IPCC-AR5. The simple downscaling method (delta change method) was used to downscaling the climate data from global scale to regional scale to generate the climate change scenario for the study area. The Soil and Water Assessment Tool (SWAT) was used to investigate the impact on water quality under climate change scenarios. The model was calibrated and validated using monthly TSS, T-N, and T-P records. The calibration and validation results indicated that the SWAT model was able to simulate the streamflow satisfactory, with Nash-Sutcliffe efficiency exceeding 0.50 for the Phuoc Hoa station, for both calibration and validation periods. Their differences in simulating the water quality under future climate scenarios were also investigated. This study was expected to provide a useful tool and reference for non-point source pollution quantification and to support water resource management and planning in the Upper Dong Nai River Basin.