Runoff conditions in the Fuping Basin under an ensemble of climate change scenarios

Changes in runoff are of great significance for water resources management, especially under the changing climate. In the Fuping Basin, one of the basins in the upper reaches of the Daqinghe Basin, the water resources are facing changes which show great importance of further studies on runoff conditions in the future in this basin. Hence, in this paper, MIKE11-NAM model was applied to simulate daily runoff (2008−2017) and future runoff conditions under a changing climate in the near future (2025−2054) in the Fuping Basin. After bias correction, an ensemble of four regional climate models (RCMs) was used to develop future climate data under three shared socio-economic pathways (SSP1-2.6, SSP2-4.5, and SSP5-8.5) scenarios. The obtained results showed a good performance of the MIKE11-NAM model in simulating daily runoff. R² and Nash-Sutcliffe efficiency coefficient (NSE) were 0.82 and 0.81 for calibration, 0.87 and 0.87 for validation, respectively. Although uncertainties remain, the correlation between observed and simulated RCM data was improved after bias correction for all models. Precipitation and temperature were projected to increase under all scenarios compared to the baseline period (1985−2014). Annual temperature and precipitation will increase by 2.45 ℃ and 124 mm under the SSP5-8.5 and SSP2-4.5 scenarios, respectively. However, precipitation is expected to mainly increase in summer while temperature will increase in all the seasons. The projected annual runoff will increase under SSP2-4.5 while decreasing under SSP1-2.6 and SSP5-8.5 scenarios. Seasonally, the future runoff will decrease during spring and summer under all the scenarios. Generally, the changes in runoff conditions will be more obvious in the future. Our findings can be important for integrated water resources management and planning in this region.