'Quantity-type' water shortages and 'quality-type' water shortages are important factors that constrain the security and coordinated development of regional water-energy-food nexus (WEFN) system, especially in arid areas where water is scarce. Therefore, it is of great significance to accurately identify the coupling and mutual feedback effects of the WEFN on different types of water resource consumption. This information can be used to understand the regional WEFN and alleviate pressure on regional water resources. In this study, a new relationship diagram of the WEFN system was formed with the incorporation of the water footprint (WF), which can characterize a system's water consumption, water source type, water pollution amount and pollution type. Based on this nexus, a WEFN system feedback model suitable for arid regions was established using the system dynamics approach. Taking Ningxia, China, as a case study, six future scenarios were designed, and the development trends of the WEFN system under different development scenarios were simulated to explore the impact of different policies on the WEFN. Finally, practical suggestions to promote the synergistic development of WEFN systems were proposed. The results indicate that water security is the main factor that constrains the coordinated development of the WEFN system in Ningxia. Incorporating water environmental pollution policies into the water subsystem is necessary. Furthermore, the resource saving pattern and energy production restructuring adjustment pattern can effectively alleviate the energy security issue that has resulted from rapid economic development. In addition, Ningxia urgently needs to optimize its food production structure to address a continuous reduction in the food security index.
 

Water-Energy-Food Nexus, Water Footprint, System Dynamics, Arid Zone, Scenario Simulation