| Water pollution in Beijing has been the focus in our country even in the world presently. The result of this investigation was just as follows:According to the results using fuzzy synthetic evaluation method, the water quality of Chaobaihe water systems was good relatively with II, HI grade mostly comparing to the GB3838-2002 national standard of surface water quality. The water quality of other three water systems including Daqinghe, Jiyunhe and Beiyunhe was contaminated seriously with water quality of V grade mostly. The water quality of Miyun reservoir was good and reached III class level, and that of Guanting reservoir was bad with eutrophication and reached IV class level. The water in Zhengzhu lake and Haizi reservoir was contaminated seriously.The spatial distribution of pollution of Beijing in large-scale map was obtained through the GIS and GPS technology with pollution trait towards Northwest and Southeast. The regions contaminated seriously concentrated in the southeast area including such districts and counties as Shunyi, Pinggu, Fengtai, Fangshan, Daxing, Tongzhou and Changping, and the related watersyems contained Beiyunhe, Jiyunhe, Daqinghe. In the areas with less anthropic activities, the water quality was not bad.Through the risk assessment on heavy metal pollution of sediments of typical water body and investigation on dissipation of heavy metals using modified soil columns, it showed that the sediment of Wenyuhe existed a strong ecological danger of heavy metals with the greatest potential ecological risk index of Cd. The amount of heavy metals for bioavailability had the greatest in the upper sediment column and reduced gradually with the depth increased, and heavy metal pollution of Wenyuhe was deteriorating in certain degree. The loss of heavy metals by leaching has close relation to soil emission and heavy metal amount of water body. The sequence for vaious teachability of heavy metals was Cd>Zn>Cu>Pb, and there was pollution risk of heavy metals from sediments in riversystems to underground water.By the assessment for the economic loss of water pollution in Beijing, the annual total amount of economic loss in 2002 was over 4 billions yuan, and the industrial loss had the greatest with the percentage of 72.63%, and other losses including human health, underground water pollution, cropsdamage, stockbreeding reached 1.108 billion with the percentage of 27.37%. A lot of survey data showed that the reason for water pollution was point source and nonpoint source.int source pollution was from industrial loads and domestic sewage, while nonpoint source pollution came from pesticides, fertilizer loss, soil erosion and night soil emission. In the areas with great industrial and agricultural activeties including districts of Shunyi, Pinggu, Chaoyang, Daxing, Tongzhou and Fangshan, the water quality was contaminated seriously; these related watersystems covered Beiyunhe, Jiyunhe and Daqinghe. The same pollution reason was obtained through principle component analysis (PCA) among various parameters reflecting water quality.Water pollution control of Beijing is a comprehensive system project, it contained not only wastewater reuse based on function planning of surface water but also various macroscopical controlling strategies for pollution source. According to the result obtained from the water quality assessment and original function planning of Beijing surface water, suggestions were raised for correction. Drinking water source should keep the original function, and the present realistic function was recommended for seriously contaminated water body (> V grade) to avoid environmental risk but more new functions could be developed for social productivity and human lives through various water treatment technology. As some controlling methods were concerned, pollution source including industrial emission, agriculture nonpoint source and domestic sewage should be delt with effiently. A series of technology should be employed and source control should be suggested, with clean p...
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