The Impact of the South-to-North Water Diversion Middle Route Project on Groundwater in the Beijing-Tianjin-Hebei Region

Abstract

Study region: ChinaStudy focus:  Based on a distributed water cycle simulation model that integrates surface water and groundwater, this study aims to develop a simulation method suitable for complex canal systems, evaluate the changes in water resources and groundwater storage in the BTH region before and after the implementation of the South-to-North Water Diversion Middle Route Project (SNWDMRP), and predict groundwater restoration under different precipitation scenarios based on the proposed water transfer scale of the SNWDMRP.        New hydrological insights: The results show that the SNWDMRP from 2015 to 2019 led to an average annual increase of 1.858 billion m3 in shallow groundwater storage in the BTH region. The model predicts that by 2030, if the proposed water transfer scale is implemented and current groundwater overexploitation management measures are maintained, shallow groundwater storage could increase annually by an average of 2.907 billion m3, 1.358 billion m3, and 11 million m3 under wet, normal, and dry scenarios, compared with 2015-2019. Additionally, deep groundwater storage may increase by 794 million m3, 704 million m3, and 617 million m3 . In the wet scenario, shallow groundwater depth in the BTH Plain may recover to its original level around the year 2000. The research findings hold practical significance for maximizing the water supply benefits of the SNWDMRP and supporting the sustainable development of water resources in the BTH region.

Keywords: Water diversion, Groundwater, MODCYCLE, Canal simulation