Water-Food-Ecosystem Nexus in Semi-arid Environment: Reconciling Economic Benefits and Ecological Sustainability

Abstract:

Agriculture and ecosystem commonly compete for water in arid and semi-arid environment. Such competition often get worse with population growth, economic development, and climate change, if not managed properly. To address this issue, we developed a regional model that optimizes agricultural and ecosystem benefits while maintaining water sustainability in a Water-Food-Ecosystem nexus framework. The agricultural module maximizes net agricultural benefits, considering cropping pattern, irrigation technologies and conjunctive use of surface water and groundwater. We use the RZWQM model to simulate agricultural drainage, which is routed to a drainage lake that supports groundwater table and groundwater-dependent ecosystem in the area. This Water-Food-Ecosystem nexus model is applied to a semi-arid area in the Yellow River basin in China, for which we analyzed the synergies and trade-offs between the agricultural and ecological systems, exploring promising water re-allocation and land management scenarios that can potentially achieve food security and ecosystem health with limited water resource.