致污事件对于桥水库水环境影响的问题研究

发布时间：2018-01-28 20:18

本文关键词： 于桥水库面源污染总氮总磷时空分布动力迁移模型　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：于桥水库是天津市重要的饮用水水源地和引滦入津工程最大的调蓄水库,承担着天津市的供水重任,是天津市社会经济发展的生命源泉,为天津市的可持续发展提供了重要的物质基础,于桥水库水质的好坏是影响天津市社会安定、经济发展的重要因素之一。近年来,随着库区周边非点源污染加剧以及上游来水营养盐负荷增大等水环境条件的变化,入库水源水质明显变差,水质污染问题越来越突出,水库水体富营养化加剧。本文以天津市饮用水水源地水环境现状为背景,以于桥水库库区为依托,充分利用现有数据资料,对于桥水库库区污染负荷及来源现状进行了分析,同时结合水库实际情况以及提高供水安全保障,运用建立的水动力水质耦合模型对设定典型工况进行模拟分析,为水库安全运行及水库下游城市供水安全提供管理和调度依据。具体研究结果如下:1.运用改进的标准农田法和排泄系数法对水库库区农业非点源污染负荷进行估算。计算结果显示:于桥水库库区7个乡镇2008年非点源污染总氮(TN)、总磷(TP)入库负荷分别为45.86t、9.28t。其中农村生活产生污染负荷量最大,所占比重分别为总氮(TN)53.7%、总磷(TP)68.6%;其次为畜禽养殖产生污染负荷。2.根据不同非点源污染工况条件的模拟结果给出如下结论:(1)汛期时,于桥水库总氮含量最高值出现在9月份,8月份为于桥水库总氮含量最低的月份。受风生流作用水库库体周边水质受污染影响明显。刘相营、五百户镇及霍家店为含氮污染物主要汇流入库口。总磷含量最低出现在9月份,7月份为总磷含量最高月份。在空间分布上表现出东高西低的趋势。水库库体南岸为总磷主要汇流入口。(2)在大洪水年的洪水期,受洪水径流冲刷作用,污染负荷量大幅度增加。但保持水库的高水位运行可以使库区流速降低,大量的污染负荷在大量水体的稀释及沉积作用下,会以较快速率降低,可使得出库水体的水质较入库时改善很多,从而可保证汛期对下游地区的供水安全。(3)暴雨时段由于强降雨对地表的冲刷、淋溶,使得大量面源污染物随降雨径流入库;由于暴雨时段降雨集中,在巨大的入库流的水动力作用下,污染带会迅速影响库区内部,在后期风场的作用下,污染面积范围变大。
[Abstract]:Yuqiao Reservoir is an important drinking water source in Tianjin and the largest regulating reservoir in Luanhe River diversion Project. It bears the heavy responsibility of water supply in Tianjin and is the source of life for the social and economic development of Tianjin. It provides an important material basis for the sustainable development of Tianjin. The water quality of Yuqiao Reservoir is one of the important factors affecting the social stability and economic development of Tianjin in recent years. With the increase of non-point source pollution in the reservoir area and the increase of nutrient load in upstream water, the water quality of water source becomes worse and worse, and the problem of water pollution becomes more and more serious. The eutrophication of reservoir water is intensified. Based on the present situation of drinking water source water environment in Tianjin and the reservoir area of Yuqiao Reservoir, this paper makes full use of the existing data. The pollution load and source status of Yuqiao Reservoir area are analyzed. At the same time, the safety of water supply is improved in combination with the actual situation of the reservoir. The hydrodynamic water quality coupling model is used to simulate and analyze the typical working conditions. To provide the management and operation basis for the safe operation of the reservoir and the safety of the water supply in the downstream city of the reservoir. The concrete research results are as follows:. 1. Using the improved standard farmland method and discharge coefficient method to estimate the agricultural non-point source pollution load in reservoir area. The calculated results show that the total nitrogen of non-point source pollution in 7 villages and towns of Yuqiao reservoir area in 2008 (. TNN. The total phosphorus (TP) input load was 45.86 t / 9.28 t, among which the pollution load of rural life was the largest, accounting for 53.7% of total nitrogen monoxide (TNN). TP 68.6; According to the simulation results of different non-point source pollution conditions, the following conclusion is given: 1) during flood season, the maximum value of total nitrogen content of Yuqiao Reservoir appeared in September. August is the month in which the total nitrogen content of Yuqiao Reservoir is the lowest. The water quality around the reservoir body affected by wind-induced flow is obviously affected by pollution. Five hundred towns and Huo Jiadian were the main confluence ports of nitrogen pollutants. The lowest total phosphorus content appeared in September. July is the highest month of total phosphorus content. The spatial distribution shows the trend of east high and west low. The south bank of reservoir is the main confluence inlet of total phosphorus. However, keeping the high water level of the reservoir can reduce the velocity of water in the reservoir area, and a large amount of pollution load will be reduced at a faster rate under the action of dilution and deposition of a large number of water bodies. The water quality can be improved a lot compared with when entering the reservoir, so as to ensure the safety of water supply to the downstream area during flood season. 3) during the rainstorm period, the surface is washed and leached due to the strong rainfall. Make a large number of non-point source pollutants with rainfall runoff into the reservoir; Due to the concentration of rainfall during the rainstorm period, the pollution zone will affect the reservoir area rapidly under the huge hydrodynamic action of the inflow, and the area of pollution will become larger under the action of the wind field in the later stage.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X524;TV697.25

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