Improving synergy of the water-agriculture-ecology system in arid areas using a novel co-optimization model
Xingyu Zhu, Xiaoling Su, Vijay P. Singh, Haijiang Wu, Jiping Niu, Lianzhou Wu, Jiangdong Chu
Abstract
In arid areas, the intricate interconnections and competition among water, agriculture, and ecology are particularly pronounced. Enhancing the synergy within the water-agriculture-ecology (WAE) system, while seeking common ground of competing sectors, presents a formidable challenge in managing water and land resources. In this study, the synergy of the WAE system was assessed using a coordinated development degree function, which was developed by considering the coefficient of variation and spatial distance projection. We investigated the multi-factor dynamic regulation of the WAE system through a water-agriculture-ecology co-optimization (WAECO) modelling framework, which adheres to a regulatory model that follows global-to-local optimization and bottom-up feedback. Using this framework, key factors, such as reservoir water supply, groundwater exploitation, and planting structure in the Shiyang River Basin (SRB), a typical arid basin in northwest China, were regulated. Results indicated crop yields and economic benefits in the baseline year reflected increments of 1.2 % and 5.4 %, respectively, compared to the actual scenario, while simultaneously increasing ecological water satisfaction by 11.1 % post-co-optimization. Through bilateral regulations between supply and demand, the annual average water deficit of the WAE system notably decreased from 7.5 % to 3.4 % in the mixed irrigation area of Liuhe midstream. The WAECO model effectively reconciled competing sectoral interests and improved the synergy of the WAE system, as indicated by a 6.3 % improvement in the coordinated development degree over the static regulation model. The new framework integrates a broad spectrum of regulatory factors and provides decision-makers with thorough and practical information, thereby facilitating the integrated management of the WAE system in arid areas. • The coordinated development degree function was defined and deduced. • A novel water-agriculture-ecology co-optimization framework was proposed. • The conflicts among key factors were reconciled by multi-factor dynamic regulation. • The model effectively improved the synergy of the water-agriculture-ecology system.