Impact Assessment And The Countermeasure Analysis Of Rail Transit Construction To Urban Water Environment

Water environment is an important element of the external environment that we rely on, the health protection of it is the basic condition of social sustainable development. As the important carrier of the inland water environment, urban river is the key to maintain the balance of urban ecosystem, has environmental protection, tourism, entertainment, culture, education, transportation and other utility value. But along with the fast urban development process, a lot of wading engineering exacerbated the damage influence of the river water environment, has become the most significant city environmental protection problem in our country and the world. This topic research aim to the evaluation analysis influence of Suzhou rail line site construction broken river engineering which damage the river water environment, and put forward the scientific and feasible compensation measures, has an important theoretical and realistic significance to guide the urban river water environment protection in the process of construction of the rail sustainable management, provide a reference for similar urban construction engineering.Based on the research of the rail site construction characteristics and the pollution screening, choosing the typical sites such as Hengshan Road station, Canglang Xinting station, West Baodai Road station, Qunxing Road station, conducted a study about the water environment impact assessment analysis which is divided into two parts such as water quality impact analysis and water ecological impact analysis.The impact assessment analysis research of the water quality use the method which choosing typical pollution index employed independent analysis and fuzzy comprehensive evaluation with the overall water environment system analysis. introducing the concept of membership function in fuzzy mathematics model and the principle of membership degree into the water quality assessment system by selecting the representative pollution factor for subset of evaluation and using national surface water standard as the evaluation set, building the fuzzy model based on the principle of membership degree to evaluate water quality. According to the strengths and weaknesses comparative of water quality evaluation index in each section and the trend after the rail site construction, it we can find that river water quality deterioration effect after the rail site construction, and the main pollutants is the organic matter and ammonia nitrogen by comparing the weight of each evaluation factor value.The impact assessment analysis research of the water ecological is mainly about the plankton comprehensive index of surface river water, including three angles such as plankton population structure, the density of plankton and zooplankton biodiversity evaluate, research the trend of ecological environment affected by rail site construction. Collecting the biological activity samples in the rail site and divided plankton population structure by biological spectrum, and then finding changes of the existence of the plankton which have ecological instruction function. Fixed collected water samples and reading the biomass of plankton, the density of plankton and plankton Margalef diversity index. The research found these indicators data are worsening, the river water ecological environment is influenced by rail construction, the river water ecological health is threatened.Finally, in view of the destruction effect of river water quality and water ecology, put forward the proposals divided into two stages as during the construction and after the construction. Through the traditional engineering measures of water quality improvement and the emerging technology measures of water ecological restoration two aspects improve the water environmental health of river area affected by the rail construction engineering.