Optimizing the balance among water use, food production, and ecosystem integrity at the regional scale

Agricultural expansion has caused groundwater overuse and ecological water loss, increasing Water-Food-Ecosystems (WFE) conflicts. Differing water interests between regional managers and farmers, along with poor WFE coordination, have impeded large-scale sustainability. To address this, we developed a multi-objective programming model at dual scales (regional and farm) that considers the feedback between water and arable land resources. The model was applied to a major irrigation region in Northeast China, which has seen substantial cropland expansion and groundwater depletion. Results show that the dual-scale model can link sustainability with water use (equilibrium amount of groundwater), food production (economic benefits of agricultural systems), and ecosystem integrity (satisfaction of wetland ecological water use). Changes in water supply and demand under different scenarios affect the total arable land area and the structure of crop cultivation. Both irrigation efficiency and water diversion can ease WFE conflicts, with water-saving irrigation providing greater economic benefits for farmers. However, efforts to reduce groundwater overexploitation and secure ecological water use may reduce economic benefits by 6.9 % and 12.2 %, respectively. These findings offer valuable insights for WFE co-development planning in regions with extensive agricultural expansion. The modeling concept at two scales is transferable to other farming systems in the world to provide practical guidelines for regional sustainable development in balancing water resources, food security and ecosystem integrity.