Enhancing the sustainability of the Water-Food-Energy Nexus within an optimization framework: A case study of Ningxia, Northwest China

• A four-objective optimization framework was developed to evaluate resource use efficiency, economic benefits, system security, and comprehensive performance. • A case study demonstrated the innovative integration of system dynamics model and multi-objective optimization algorithms for complex resource management. • The modeling process revealed inherent trade-offs and synergies among optimization objectives within the Water-Food-Energy Nexus (WFEN) under different scenarios. • The results provide decision-support insights for cross-sectoral coordination and sustainable governance within the WFEN. Water, food, and energy are essential resources for human survival and socio-economic development. The complex interconnections have positioned the Water-Food-Energy Nexus (WFEN) as a critical framework for achieving integrated and effective resource allocation, while maintaining the stable operation of coupled systems. This study, for the first time, proposes a novel WFEN-based multi-objective optimization framework that integrating system dynamics (SD) modeling, the non-dominated sorting genetic algorithm III (NSGA-III), and the weighted technique for order preference by similarity to ideal solution (TOPSIS) approach. This integrated framework enables dynamic, year-by-year optimization and comprehensive performance assessment across multiple scenarios, thereby facilitating rational resource allocation and enhancing overall system sustainability. The framework quantifies the impacts of key decision variables such as crop planting areas, irrigation quotas, and energy quotas on the system mechanisms, thereby revealing the complex coupling between feedback loops and policy regulation. A regional case study in Ningxia, northwest China, was conducted to implement and validate the proposed method. The SD model demonstrated high reliability, with simulation relative errors consistently below 10 % during the study period, indicating its suitability for representing the real-world conditions in the study area. The solution sets obtained from the multi-objective optimization exhibited substantial diversity and convergence, underscoring the effectiveness of the proposed integrated method. Under the top1 ranked solution selected by the weighted TOPSIS method, from 2011 to 2022, regional security indicators improved significantly: the Water Security Indicator (WSI) increased from 1.31 to 1.76, the Food Security Indicator (FSI) increased from 0.31 to 0.80, the Energy Security Indicator (ESI) increased from 0.51 to 1.05, and the Water-Food-Energy Security Indicator (WFESI) increased from 0.59 to 1.14. Incorporating integrated management principles into policymaking enables this study to break away from conventional single-sector policy frameworks. Moreover, by adjusting key variables that link across sectors, the proposed framework offers a promising pathway toward win-win synergies and sustainable prosperity in the regional water, agriculture, and energy systems.