基于SWAT模型的沙颍河上游非点源污染模拟研究

发布时间：2018-03-03 16:11

本文选题：沙颍河上游　切入点：非点源污染　出处：《南京大学》2015年硕士论文　论文类型：学位论文

【摘要】：目前,我国水环境污染形势十分严峻,随着点源污染得到逐步地控制,非点源污染已经成为水环境恶化和湖泊富营养化的重要来源。因此,定量化评价非点源污染负荷,对于水生态环境保护具有重要意义。本文在淮河流域重要江河湖泊水功能区水质达标评价的基础上,选择水质达标率最低的沙颍河上游为研究区域,建立SWAT模型,对沙颍河上游的非点源污染进行时空变化的模拟及其评价,分析该流域的主要污染来源,以期为沙颍河上游非点源污染的控制和管理提供参考依据。主要研究结论如下：(1)建立了沙颍河上游的非点源污染负荷模型。综合研究区域地形、土地利用、土壤类型、闸坝调度等,进行模型的率定及验证。验证结果表明,流量及污染物质的实测与计算模拟决定系数R2、Nash-Suttcliffe系数Ens和相对误差Re均达到模型建立的精度要求。(2)模拟评价了沙颍河上游区域径流过程和非点源污染负荷。2007年,沙颍河上游周口断面年径流量和氨氮年产出总量分别为31.3亿m3和108516kg；2008年,沙颍河上游周口断面年径流量和氨氮年产出总量分别为19.3亿m。和124019kg。2007-2008年沙颍河上游周口断面氨氮年均产出总量为116267.5kg,其中,来自于非点源的氨氮年均产出总量为5946.6kg,占河道氨氮负荷总量的5.1%,沙颍河上游河道中的氨氮主要来源为上游点源污染排放。(3)模拟了沙颍河上游非点源污染负荷的空间分布。在2007-2008年间,沙颍河上游地区年均单位面积总氮产出量范围为5-30 kg/ha。其中,尉氏县、中牟县东部、扶沟县北部、禹州市中部、鄢陵县中部、扶沟县东部、襄城县南部、周口市南部和郾城县的年均单位面积总氮产出量最高,产出量范围为25-30 kg/ha;2007-2008年沙颍河上游年均单位面积总磷产出量范围为0.5-5 kg/ha。其中,许昌市、临颍县、鄢陵县中部、扶沟县东部、襄城县西部、周口市南部和郾城县的年均单位面积总磷产出量最高,产出量范围为3-5 kg/ha。(4)分析了沙颍河上游非点源污染负荷分布的影响因素。降雨、径流及土地利用类型对非点源污染负荷的产出影响很大。其中,降雨、径流与河道氨氮负荷之间有强的正相关性,降雨和氨氮负荷的相关系数为0.52,径流和氨氮负荷的相关系数为0.74。土地利用类型中,耕地与流域单位面积非点源污染负荷产出量呈明显的正相关,林地与流域单位面积非点源污染负荷产出量呈负相关,表明人类活动对非点源污染负荷的输出影响较大。
[Abstract]:At present, the situation of water environment pollution in China is very serious. With the point source pollution being gradually controlled, non-point source pollution has become an important source of water environment deterioration and lake eutrophication. On the basis of evaluating the water quality of the important river and lake water function area in the Huaihe River Basin, this paper selects the upper reaches of Shaying River with the lowest water quality up to the standard as the research area, and establishes the SWAT model. The spatiotemporal variation of non-point source pollution in the upper reaches of Shaying River was simulated and evaluated, and the main pollution sources in the basin were analyzed. In order to provide reference for the control and management of non-point source pollution in the upper reaches of Shaying River, the main conclusions are as follows: 1) the model of non-point source pollution load in the upper reaches of Shaying River is established. The rate determination and verification of the model are carried out. The verification results show that, The runoff process and non-point source pollution load in the upper reaches of Shaying River were simulated and evaluated by the measured and calculated determinant coefficients R2N Nash-Suttcliffe coefficient (Ens) and relative error re (re) in the upper reaches of Shaying River. In 2007, the runoff process and the non-point source pollution load in the upper reaches of Shaying River were evaluated. The annual runoff and ammonia nitrogen output of Zhoukou section in the upper reaches of Shaying River are 3.13 billion m3 and 108516 kg, respectively. The annual runoff and ammonia nitrogen output of Zhoukou section in the upper reaches of Shaying River are 1.93 billion m and 124019 kg 路2007-2008, respectively. The average annual output of ammonia nitrogen in Zhoukou section of the upper reaches of Shaying River is 116267.5 kg. The annual output of ammonia nitrogen from non-point sources is 5946.6 kg, which accounts for 5.1% of the total ammonia nitrogen load. The main source of ammonia nitrogen in the upper reaches of Shaying River is the upstream point source pollution discharge .Y3) the empty load of non-point source pollution in the upper reaches of Shaying River is simulated. Between 2007 and 2008, The average annual total nitrogen output per unit area in the upper reaches of Shaying River is 5-30 kg / ha. among them, Weishi County, Eastern Zhongmu County, North Fugou County, Central Yuzhou City, Central Yanling County, Eastern Fugou County, Southern Xiangcheng County, The annual total nitrogen output per unit area in southern Zhoukou and Yicheng counties is the highest, with the yield range of 25-30 kg / ha per year from 2007 to 2008 in the upper reaches of Shaying River, ranging from 0.5 to 5 kg / ha. among them, Xuchang City, Linying County, Yanling County, Central Yanling County, and East Fugou County, In the west of Xiangcheng County, south of Zhoukou City and Yicheng County, the annual total phosphorus production per unit area is the highest, and the output range is 3-5 kg / ha. 4) the factors influencing the distribution of non-point source pollution load in the upper reaches of Shaying River are analyzed. Runoff and land use type have great influence on the output of non-point source pollution load, among which, there is a strong positive correlation between rainfall, runoff and ammonia nitrogen load. The correlation coefficient between rainfall and ammonia nitrogen load is 0.52, and the correlation coefficient between runoff and ammonia nitrogen load is 0.74. In land use type, there is a significant positive correlation between cultivated land and non-point source pollution load per unit area of watershed. There is a negative correlation between forest land and the output of non-point source pollution load, which indicates that human activities have a great influence on the output of non-point source pollution load.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52

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