Surface Water And Groundwater Coupling Simulation Research In Heihe Basin Of Shaanxi

Water is the basic survival resources for human. For a long time, because the unreasonable human water use makes the shortage of water resources, the crisis of water cycle process affects the societal and economical development. The landform of the northwest region of China is complex; the terrain extends upward and downward; the dry climate and low plantation coverage make intense interactions in the natural systems under the trend of global warming. Especially the surface water and groundwater circulation processes in the arid and semi-arid area have vital significance for the water resources integrated planning for the northwest region in China. The Heihe River in Zhouzhi County is the water supply field for Xi’an city. In this study, the Heihe River basin was selected as the research region. On the basis of the drainage basin information and the support of the GIS technology, this study simulated the runoff of the Heihe River downstream, obtaining model validation period monthly runoff correlation coefficient R2 of 0.89 and model efficiency coefficient of 0.85. The study further coupled SWAT model wirh MODFLOW model to analyze the surface water and groundwater systems in the study area. The hydrological response unit(HRU) and finite difference grid(cell) of MODFLOW model are the basic exchange units for the surface water and groundwater. The results indicate that the coupled model can preferably simulate the groundwater resources of the Heihe River basin and the interaction of surface water and groundwater.