Optimization of Water-Food Nexus System under Dual Uncertainties

In this study, a fuzzy chance-constrained programming (FCCP) method is developed to synergetic plan water-food nexus (WFN) system under dual uncertainties. The developed method can tackle uncertainties expressed as probabilistic distribution and flexible parameter. Then, a FCCP-WFN model is formulated for the city of Jinan (China), in which 72 scenarios are designed with the consideration of different food demand levels, constraint-violation risk levels, and satisfactory degrees. Results indicate that (i) surface water would be the main water source for Jinan (accounting for 62.7% of water supply), and agriculture would be the largest water consumer (accounting for 55.5% of water allocation), therefore, rational management of surface water and reduction of agricultural water allocation are essential to alleviate the water shortage problem in Jinan; (ii) the annual arable land area is 628.4×103 ha to 683.4×103 ha, of which grain crops account for 62.1%, and the sufficient grain planting area can ensure food security in Jinan; (iii) uncertainties have significant influence on water allocation schemes, thus, managers should consider the impact of uncertainties during decision-making process, and make different management schemes according to different attitudes to system risks under undetermined conditions.