Research On The Development Planning And Evaluation Of City Water Cycle System

Water resource is the irreplaceable material basis for human being and important supply for the economic development of cities. However, with the continuous expansion of size of city, water shortage becomes a more and more serious problem. The deterioration of water quality becomes the limit for urban development and the improvement of living standards of the people. The water cycle system should be built with the sustainable development strategy. The water resource from different sources should be distributed rationally and the sustainable development of the water cycle system should be evaluated with suitable methods.Taking city water cycle system as the research target, the issues of its development planning and evaluation index system were discussed with the sustainable development strategy in this paper. With the systematic analysis of urban water demand structure and the characteristics of its changes, the urban water demand was forecasted. The evaluation index system of city water cycle system was developed with the theory of value engineering and the uncertain programming model was build for the sustainable development.An integrated method for forecasting the urban water demands was proposed in this paper based on its structural features and influencing factors. Standard index method, seasonal index smoothness method and PSO-BP algorithm were used to forecast the urban general water demand. The methods of water consumption index for unit GDP and unit land usage were used to forecast the industrial water demand. The analysis and comparison were conducted for the various forecasting methods. The prediction of the urban water demand by the integrated method ban be used as the basis for the development planning of the water cycle system.The evaluation index system was built for the sustainable development of city water cycle system in this paper. Based on the value engineering theory, the level (value) of the sustainable development of city water cycle system was divided into two parts, function and cost. The evaluation indexes were built corresponding to the relative aspects of the system development. The structural characteristics of the system operation and their interactive relations were analyzed with FANP analysis method.Based on the stochastic variation characteristic of the urban water demand, the uncertain programming model was build for the city water cycle system development. Based on the planning principles for sustainable development, a multi-objective programming model was build, taking the economic, social and environmental aspects into account. The uncertain variables in the planning model were simulated with Monte Carlo method. Then the planning model was solved with the non-dominated sorting genetic algorithms embed with Monte Carlo method.A city water cycle system of a coastal city in north China was used as a case study in this paper. The relevant theoretical knowledge and methods were applied in the development planning, which includes the evaluation of the sustainable development level and the construction and solving of the planning model. The methods applied in this paper could provide effective decision support for the water cycle system.