Research on the urban water resources carrying capacity by using system dynamics simulation

The relationship between water resources and the social economy has become a restricting factor for the sustainable development of cities around the world. Based on the urban development demand and water resources condition of Linhai City in eastern China, which has the fastest economic growth and population boom, the system dynamics model of water resources carrying capacity was established to analyze the interaction between society, economy and water resources. According to the different development emphases, six different modes of water resource utilization were designed. Taking total population, GDP, industrial output value, tertiary industry output value, water consumption, water supply and sewage discharge as the measurement indexes, the research predicted the development status of water resources carrying capacity of Linhai City from 2015 to 2030 under different development modes. Through the simulation results, it is found that the water-saving measures can reduce the gap between water supply and demand only in a short term. In the long run, the adjustment of industrial structure can improve the water resources carrying capacity and simultaneously promote the economy. In addition, increasing the water income sources as well as strengthening sewage treatment are also necessary to balance the water supply and demand.