Hydrological response to climate change: The Pearl River, China under different RCP scenarios

Study region: The Pearl River, located in the south of China, is the second largest river in China in terms of streamflow. Study focus: The study aims to assess the impact of climate change on seasonal discharge and extreme flows. For the assessment we use the variable infiltration capacity (VIC) model driven by bias-corrected results of five different climate models under the IPCC scenarios RCP4.5 and 8.5. New hydrological insights for the region: Previous studies focussed on annual discharge and extreme flood events in the basin. However it is also important to assess variations in low flow across the basin, because it is suffering from water shortage and salt water intrusion in the dry season. Results indicate a reduction in average low flow under the five climate models. The reduction varies across the basin and is between 6 and 48% for RCP4.5. River discharge in the dry season is projected to decrease throughout the basin. In the wet season, river discharge tends to increase in the middle and lower reaches and decrease in the upper reach of the Pearl River basin. The variation of river discharge is likely to aggravate water stress. Especially the reduction of low flow is problematic as already now the basin experiences temporary water shortages in the delta.