Study On Sustainable Exploitation And Utilization Of Water Resources In Urban Areas

Most of cities in China suffer from both problems of water scarcity and water pollution. The reasonless water resources exploitation and utilization not only resulted in and aggravate the problems, but also bring a series of other problems such as financing waste and environment problems. The traditional development viewpoint and economic increase viewpoint resulted in the reasonless water resources exploitation and utilization model. So, it is urgent to study the sustainable water resources exploitation and utilization based on the philosophy of cyclic economic.It is important to utilize unconventional water resources for realizing water resources sustainable utilization in urban areas. It is at the stage of start to utilize unconventional water resources in China, the correlative technology, criterion, policies are imperfect. Firstly, the principle of water resources sustainable utilization in urban areas is put forward based on the sustainable development viewpoint and the philosophy of cyclic economic. Through collecting the literatures about unconventional water resources utilization and consulting specialists, the economy, technology and effect on environment are analyzed, the models of unconventional water resources utilization suitable for specific situations of China are put forward.An integrated benefit assessment model (IBAM) for the urban-water-resource-related policies is established on the basis of the analytic hierarchy process (AHP). A system of integrated benefit assessment indices (SIBAI), with comprehensive reflections on social, economic and environmental interests, is proposed, guided by the sustainable concept and the cyclic economic philosophy. The IBAM provide a method to decision-making the priority order of all kinds of water resources exploitation. The integrated benefit of measure, such as saving water, rain water utilization, water recycling, seawater desalination, and the South-to-North diversion project are appraised qualitatively. The IBAM and SIBAI are then applied to appraise quantitatively such cases as water recycling, seawater desalination, and the South-to-North diversion project, in Tianjin city. It drew a conclusion that the integrated benefit of the water recycling is far greater than the seawater desalination and the South-to-North diversion project, Tianjin should step up its investment in the waste water recycling projects and nurture the sewage recycling programs as a priority. As seawater desalination involves high consumption of energy, the water available for Tianjin in the near future is far less than the South-to-North Water Diversion section will offer. For such a metropolitan worst affected by water shortage as Tianjin, this is an important factor which leads to the fact that the integrated benefits of seawater desalination measures are lower that those of the South-to-North Water Diversion section.The water resources exploitation optimize model (WREOM) is established based on the multi-object planning. The WREOM reflects on social development demand, energy sources saving, water environment protecting and etc, the cost of fathering water pollution is brought into the total cost of water resources exploitation, which makes it possible that a project with saving energy sources, environment friendly property and relatively low cost is selected from all kinds of projects. The aim of WREOM is a unification of social, economic and ecological benefits. The WREOM will tell a priority project which include the model of all kinds of water sources exploitation and how degree all kinds of water sources should be exploited.The last, the WREOM is applied to optimize the project of water resources exploitation in Tianjin city. It drew a conclusion that the cost and energy source consuming are very high for satisfying the demand to water in Tianjin city in 2010 at the status quo level of utilizing water. Tianjin city should enhance the level of saving water and adjust the structure of industry. Whether at the status of saving water or saving water and adjusting the structure of industry, Tianjin city can't resolve the problem of water scarcity through exploiting conventional water sources and unconventional water sources, it is necessary to rely on the South-to-North Water Diversion (SNWD) Section, but, the quantity of diversion water needs to confirm through taking into account comprehensive social, economic and environmental interests. On the basis of optimized project, the quantity of diversion water planned is bigger. Through saving water, the quantity of water to demand isn't as large as it planned, the size of seawater desalination mode should be confine which consumes large of energy sources. The quantity of 150 million ton seawater desalination every year planned is larger in 2010. Among unconventional water sources and Water Diversion from far away, sewage should be priority exploitation. It is necessity choose of the higher ratio of treating with and recycling of sewage in Tianjin city.