INTEGRATED SURFACE WATER-GROUNDWATER MANAGEMENT IN ARID REGIONS: LESSONS FROM HEIHE RIVER BASIN IN CHINA (Invited Presentation)

In China’s second largest endorheic river basin, Heihe River Basin (HRB), the croplands in Hexi Corridor (a vital passageway of the ancient Silk Road) sucked up the river flow and groundwater, causing serious ecological problems (e.g., drying-up of terminal lakes and dying of culturally significant Populus euphratica trees) in the lower HRB. The water conflict was most sharp in 1990s. A restoration plan based on environmental flow regulation was implemented since the early 2000’s. We investigated the role that the groundwater system has played in the complex water-ecosystem-agriculture (WEA) nexus in the HRB, as well as strategies for integrated surface water-groundwater management, based on a system modeling approach. This presentation introduces our major findings with regard to buffering effects of groundwater reservoir, tradeoff between ecosystems and agriculture tuned by pumping management, synergistic and offset effects of surface water diversion regulation and pumping control, impact of heterogeneous and dynamic groundwater management policies, and threshold effects of groundwater management policy. Our study results provide valuable information for enhancing water, food and ecological securities in inland arid regions.