Research On Water Environment Capacity In Jinan Reach Of Xiaoqing River

Water is not only indispensable and irreplaceable natural resources for human life, economic development and stability of the society, but the important part of the environment. Because of the shortage of the water resources and increasing water pollution, it has become the bottleneck for economic growth in many areas. The stability and development of the society are influenced by the increasing water pollution. The reason of water pollution can lead to tremendous losses to economy in every year. The one of important reasons of water pollution can be attributed to the misuse of water environment capacity.Making a comprehensive, systematic and all-round analysis for the quality of water and environment capacity, deciding the maximum limitation of pollution discharge is the basis of the implementation of total discharge control of water pollution and the protection and exploitation of water resources. So carrying out and working out the water environment capacity is the foundation of setting up the target for total pollution discharge and improving the protection of water environment that can coordinately match with the economic development.Xiaoqing River is a big man-made channel in Shandong province. It is used as draining off flood, sailing, irrigation and sewage drainage. It is used as draining off flood, sailing, irrigation and sewage drainage, as well as, the sole connection between river and sea and also can be used as the channel of sea-land transportation. The valley covered by Xiaoqing River is the area with developed industry and concentrated residence, which is a very important foundation of industry and agriculture production in Shandong province too. Recently with the development of industry and agriculture production and the increasing of population, a great deal of waste water and domestic sewage has been produced. But a mass of them directly discharged into Xiaoqing River and lead into the pollution and deterioration of surface water environment.On the basis of water environmental functional reach compartmentalization of surface water in Jinan City, the thesis takes a research on the main pollution sources drained into Xiaoqing River and adopts Equivalent Pollution Load Method to analyze and identify the main sources and pollutant,namely COD(Chemical Oxygen Demand ),NH3-N,as well. In additional the thesis makes a comparison on evaluation method on quality of water environment. According to the monitoring data about the water quality of Xiaoqing River in Jinan reach from 1997 to 2006, the thesis takes an assessment on quality of the water environment of the reach by the method of comprehensive pollution index and then makes a research on trend of water quality change of the river.The thesis makes a comparison among three computational models, respectively Zero-Dimensional Model, modified One-Dimensional Modelâ… and Modelâ…¡, which is about water environment capacity. And then the thesis works out the computational model of water environment capacity of Xiaoqing River in Jinan reach, namely the one dimension steady-state model of water quality with longitudinal coefficient of diffusion. According to the monitoring data from 2001 to 2006 of every hydrometric station along Xiaoqing River, we proposed the empirical formula between flow rate and other hydrographic parameters. Considering the change of stream gradient, we estimated the parameter of longitudinal coefficient of diffusion in different reaches. With the 90% guaranty rate of average monthly flow rate at the lowest water in record of Xiaoqing River in Jinan section, the average flow rate in the lowest month within recent 15years, the average flow rate in the lowest seasons within recent 15years, the low water period of recent 15years, we classified four categories of circumstances as the premise of hydrographic design and worked out the water environment capacity quite exactly. We regard the water capacity below 90% guaranty rate as the theoretic result of water environment capacity of Xiaoqing River in Jina Reach.On basis of the result on water environment capacity, the thesis also set up the target to reduce the pollution in the river and gave some proposals on water quality protection as well. By taking the measure of construction, management and ecology, establishing the city sewage discharge system that can be matched with the development of modern city, cutting down the pollution and divide flow, supplement the source with new water, dredging up the mud on river bed, regulating the sewage discharge along the river banks, we can recover the ecology, landscape, flood discharge function and so on. And we also can improve the ecological cycle of the city into a sustainable way at the same time.