Simulation modeling for water governance in basins based on surface water and groundwater

Accelerating future water shortages in the world require a development of operational water governance models as illustrated by the case studies. Conversion process and its coupling simulation of surface water and groundwater are the foundation of water resources development, utilization, and scientific evaluation. In order to simulate the impact of climate change on the water cycle in basins, the quasi-distributed watershed Surface Water (SW) model was coupled with the fully-distributed Ground Water (GW) model in the simulation. The Hydrologic Response Units (HRU) in the SW model were exchanged with cells in the GW model. By using the HRU–CELL conversion interface, the distributed groundwater recharge rate (RCH) and the groundwater evapotranspiration (EVT) calculated by the SW model were imported into the RCH and EVT modules of the GW model. The application of groundwater simulation in the Heihe River basin demonstrated that the correlation coefficient between the simulation results and the measured values was 0.89, the deterministic coefficient of the simulation results was 0.86. Under future predictions the discharge from the Heihe River will decrease in the first 20 years (2020–2039). In the later 20 years (2040–2059) the discharge will increase. The simulation groundwater along with the recharge value showed the same change trend of the measured groundwater level. The coupled SW–GW model was capable of predicting the future water cycle.