【作者】 高学民；

【导师】 陈静生；

【作者基本信息】 北京大学 ， 自然地理学， 2000， 博士

【摘要】 管理和保护好长江水质对长江经济带社会、经济的可持续发展具有十分重要的意义。本研究的目标是尽可能全面系统地收集长江水系水质资料（计收集到1958年-1990年长江水系共540监测点的约10万个逐次水质监测数据和长江沿程10个城市共近20条内河内湖1990年-1996年的约1500个月均值和年均值数据），应用多种较新方法（如LogisticRegression、GIS中的水文模拟等方法），对长江水系的主要污染性水质参数(氧平衡参数——DO，BOD，COD，和营养元素参数——NH₃-N，NO₃-N，TN，PO₄^3--P等)进行评价和模拟，为长江水质管理和控制提供基础性依据。 本文分四部分：1) 对长江干流、主要支流以及沿江大湖进行水质评价研究，查明这些水体的氧平衡参数和营养元素参数的区域分布、季节变化和30～40年来的演化趋势 2)对长江沿程10个主要城市（上海、南通、无锡、常州、南京、合肥、九江、武汉、宜昌、重庆）内河、内湖的水质进行评价研究，查明其与城市人口、经济发展和污染负荷的关系；3) 运用克立格插值法和Logistic Regression法研究长江水系氧平衡参数和营养元素参数的空间结构特征及其与区域自然条件和社会经济发展的关系。4) 长江流域非点源污染的水质模拟研究。在ARC／INFO的GRID模块基础上，运用空间分析对水文过程的模拟功能，模拟长江流域非点源污染对长江沿程河湖的污染贡献。 通过上述研究获如下主要结论： 1．关于长江水系水质，长江干流水质基本良好；长江干流上游水质明显好于下游；长江干流存在严重程度不同的岸边污染带，重庆、上海、武汉、南京附近的岸边污染带最长。 2．关于长江一级支流水质，在长江的一级支流中，以上游的沱江、下游的大运河和黄浦江的水质污染最为严重，其它一级支流水质总体上尚好。 3．关于长江沿程大型湖泊的水质，巢湖和太湖的富营养化程度严重；鄱阳湖和洞庭湖水质尚好，但也存在富营养化趋势。 4．关关于长江沿程城市内河内湖水质，长江沿程城市的几乎所有内河内湖都已受到较严重和严重的污染，其污染程度与人口的数量和密集程度、与城市发展程度和城市污染负荷有很强的相关性。 5．关于水体水质的年内变化，长江上游污染程度较低的水体枯水期水质明显好于丰水期，与丰水期上游流域非点源污染加重有关；长江下游污染程度较高的水体丰水期水质好于枯水期，与丰水期降水对点源污染的稀释作用有关；由于上二因素的复杂影响，大多数河流水质的年内变化无明显规律。 6．关于某些水质参数的长期演化趋势，对污染较轻的干支流（主要位于长江上游）而言，自上世纪50年代至90年代，水质无明显变化；而对污染较重的干支流（主要位于长江中下游）而言，自60年代至90年代水质变化十分显著，主要是污染程度大大加重，如沱江李家湾站COD_Mn含量60年代的为1.8 mg／l，至90年代达6.1 mg／l，总氮的含量60更多还原

【Abstract】 Water quality is very significant to sustainable social-economic development of economics zone of the Yangtze River. The object of the study is to assess and model water quality with major parameters (e.g. DO, BOD, COD, NH₃-N, NO₃-N, TN, PO₄^3-) using some new methods （e.g. Logistic Regression, Hydrologic Process Modeling in.GIS） on the base of full-scale collection of water quality data for the Yangtze River, to serve for water quality management and control of the Yangtze River Basin. Ultimately over 100,000 monitoring data of 540 hydrometrical stations in the Yangtze River system from 1958 to 1990 and over 2,000 month or year averages of 20 local rivers （and lakes） in 10 cities along the Yangtze River from 1990 to 1996 were collected.The study includes four parts: 1) Assessment of water quality of mainstream, major tributaries, and lakes along the Yangtze River （regional distribution, seasonal variance, and evolution trends during 1960s to 1990s of water quality parameters （oxygen-equilibrium parameters and nutrients parameters）, 2） Assessment of water quality of local rivers or lakes of 10 cities （Shanghai, Nantong, Wuxi, Changzhou, Nanjing, Hefei, Jiujiang, Wuhan, Yichang, Chongqing） along the Yangtze River, 3) The spatial distribution of oxygen-equilibrium parameters and nutrients of the Yangtze River Basin and the relationship between which and regional nature conditions and social-economic development, 4) Non-point source modeling of water quality of the Yangtze River Basin using GIRD module in ARC/INFO, the contribution of non-point source contamination to the Yangtze River system.The main conclusions are as follows:1. Water quality of mainstream of the Yangtze River is still good; Water quality of upper reaches of the mainstream is better than that of lower reaches; There exists river-shore contaminated zone near the cities along the mainstream which located especially in Chongqing, Wuhan, Nanjing, and Shanghai Reaches.2. Of the major tributaries of the Yangtze River, the Great Cannal, the Huangpu River, and the Tuo River are polluted seriously while the others are better.3. Of the big lakes along the Yangtze River, eutrophications of Chao Lake and Tai Lake are heavy; Water quality of Dongting Lake and Poyang Lake is basically good, but there exists eutrophical trends.4. Almost all local rivers and lakes of 10 cities along the Yangtze River are polluted or polluted heavily, of which the pollution levels are related well with population, development, and pollution discharge loads of cities.5. In polluted slightly reaches of the rivers, water quality in dry seasons is significantly better than that in the flood seasons. This phenomenon perhaps is related to the non-point source pollution in the flood period. In polluted heavily reaches of the rivers, water quality in dry season is significantly worse than that in the flood seasons. This phenomenon perhaps is related to powerful dilution to point pollution in the flood period. Because of complex influence of the two更多还原