Water–Energy–Land Reallocation and Multiobjective Optimization in the Agricultural System

Food is important for long-term national peace and stability. Land, water, and energy are essential resources that support food production. Conflicts among economic, social, and environmental objectives are inevitable in agricultural systems. On the basis of the concept of the water‒energy‒food (WEF) nexus, this study presents an interval multiobjective nonlinear optimization model to balance the conflicts of agricultural systems. This optimization model is then applied to Jiangsu Province to verify its applicability. Using the model, the optimal allocation of land, water, and energy and the corresponding system benefits under ten scenarios are obtained. The results show that wheat has the largest planting area when the decision is biased toward economic objectives. Planting more rice can improve the environment, and planting less rice can strengthen social fairness. The water and energy allocated to crops gradually decrease as decision-making preferences shift from the economy to society and the environment. The results also indicate that the comprehensive scores under scenario S4 (society → environment → economy) reached the ideal state among the seven multiobjective scenarios. Compared with the control year (2020), the optimal total land allocation in scenario S4 is reduced by 17.49%-17.84% to ensure food security. Notably, economic profits decrease by 6.68%-38.6%, social fairness significantly improves by 45.39%–55.62%, and total carbon emissions decrease by 8.88%–25.78%. This study can help decision-makers obtain a management scheme for maximizing comprehensive interests in the agricultural WEF nexus system.