System dynamics analysis of water supply and demand in the North China Plain

Water resource carrying capacity (WRCC) is an important metric for regional sustainable development in China. It is defined as the difference between the total water supply and demand. The North China Plain (NCP) currently faces a serious water shortage if the WRCC is not managed at a sustainable level. This study focuses on applying system dynamics (SD) methodology to evaluate different water use scenarios and their associated WRCC for the NCP. System characteristics of local water resources and demand in the NCP are captured and simulated using VENSIM (R) software. A SD model of the WRCC is constructed which consists of five sub-systems: agricultural irrigation, population growth, urbanization level, water recycle and industrial output. The impact on the WRCC is tested through three growth scenarios: keeping the status quo, aggressive industrial growth and modest growth combined with wastewater recycle. Based on the simulation results, the WRCC that can most likely sustain economic growth without overly stressing the water supply is the one with modest growth combined with waste-water recycle.