water Article Interaction between Surface Water and Groundwater in Yinchuan Plain Zizhao Cai 1,2, Wenke Wang 1,*, Ming Zhao 1, Zhitong Ma 1, Chuan Lu 2 and Ying Li 3 1 School of Water and Environment, Chang’an University, Anta Road 126, Xi’an 710054, China;
[email protected] (Z.C.);
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[email protected] (Z.M.) 2 Institute of Hydrogeology and Environmental Geology, Shijiazhuang 050061, China;
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[email protected]; Tel.: +86-29-8233-9291 Received: 25 July 2020; Accepted: 15 September 2020; Published: 21 September 2020 Abstract: The interaction of surface water (SW) and groundwater (GW) is becoming more and more complex under the effects of climate change and human activity. It is of great significance to fully understand the characteristics of regional SW–GW circulation to reveal the water circulation system and the effect of its evolution mechanism to improve the rational allocation of water resources, especially in arid and semi-arid areas. In this paper, Yinchuan Plain is selected as the study area, where the SW–GW interaction is intensive. Three typical profiles are selected to build two-dimensional hydrogeological structure models, using an integrated approach involving field investigation, numerical simulation, hydrogeochemistry and isotope analysis. The SW–GW transformation characteristics are analyzed with these models, showing that geological structure controls the SW–GW interaction in Yinchuan Plain. The SW–GW flow system presents a multi-level nested system including local, intermediate and regional flow systems.