Water Resources and Power

Based on the daily observation data of 74 rainfall stations and the daily runoff data of the Wuzhou Hydrological Control Station in the Xijiang River Basin from 1964 to 2021, assisted with terrain elevation, land use and soil properties, a fully distributed physical hydrological model Liuxihe and the lumped model Xin'anjiang model were adopted to simulate the rainfall-runoff process in the basin. The Beijing Climate Center Regional Climate Model(BCC＿CSM1.1) was employed to carry out a future rainfall analysis of the Xijiang River under the RCP4.5 and RCP8.5 climate change scenarios druing 2022-2099 in the future. The results show that both Liuxihe and Xin'anjiang models are suitable for the simulation of Xijiang River basin located above Wuzhou Station, and the simulation efficiency for daily runoff are both above 0.85. However, the Liuxihe River model has outperformed Xin'anjiang model for peak flow simulations while the Xin'anjiang model has better performance in low flow discharge. During the base period(1964-2021), the simulated mean values of monthly runoff under the two future climate scenarios are not much different in the same hydrological model. Nevertheless, the flood frequency analysis shows that the magnitude and frequency of future flood disasters will be more severe than the same base period. Overall, peak flows for future extreme flooding in the basin are expected to increase.