Simulation Of Water Resources Carrying Capacity Of Yiwu City

Aim at the complex characteristics of water resources carrying capacity system of Yiwu city, this paper uses the theories and methods of the system dynamics, has established the SD model of Yiwu water resources carrying capacity, supporting capacity, and simulate it by calculating. Main research results are as follows:(1) Based on the characteristics of the system dynamics and its advantages of solve problems, the paper has established the SD model of Yiwu water resources carrying capacity by comparing the existing methods. Five subsystems including population, industry, agriculture, environmental protection and water resources have established. Appling the Vensim software, the paper has established a systematic feedback structure, then determines its causality and SD model flow diagram. The model includes 7 level variables and rate variables, 25 auxiliary variables, 12 table functions and 27 constants.(2) Based on the characteristics of water resources carrying capacity system in Yiwu city, the paper has identified 16 decision variables and established water resources carrying capacity decision variables index system of Yiwu city. After testing the validity of the model, four forecasting programs have designed according to the economic, social, environmental status quo. Through the simulation program, the paper has carried out quantitative analysis on the water resources carrying capacity based on different programs(3) Through analysis and comparison, conclusions have received that the best option to improve the water resources carrying capacity of Yiwu is to open-source, save water, treate sewage and transfer water from outside. Accoring to the program, in 2020 the water carrying capacity will amount to 449 million m~3, while the demand of total water will be 424 million m~3. The supply and demand of water resources balance on the whole, a slight amount of suppling water is residual, and the water resources will be fully, reasonably and effectively exploited and utilized.(4) Finally, operable and specific measures and advance have been put forword, according to the optimum program.