| Guanting Reservoir is the first great reservoir after the celebration of People' s Republic of China,which was ever an essential drinking water source of Beijing City. As a result of a number of sewage from industries and living,it was forced to exit the system of drinking water source till 1997. With the increasing conflict between supply and demand,Beijing municipal committee and government made up their minds to improve water quality,and to resume the original function as municipal drinking water source,and to supply sufficient drinking water with adequate quality by the year 2005. This research carried through under the background.The contaminants absorbed in the sediments,which stand the bottom in waters,can be released into the overlying water through the following processes,such as disabsorb,dissolve,as well as biodegradation,then posed a threat to the aquatic environment,ultimately led to "secondary pollution" . Even when all of external pollution sources were controlled effectively and the water quality objectives achieved,contaminants in the sediments still enter overlying water and resulted in eutrophication.Characteristics of surface sediments and column sediments are analyzed and assessed with these methods of field investigation,monitoring system and laboratory chemical analysis etc.,and multidisciplines of hydrology,agrology,environmental science along with ecology science,as well as cartography software Maplnfo and statistics software SPSS. In addition,after integrated with the analysis of pollutionhistory,pollution source and sediment fill up,vital areas and vital pollutants,integrated technologies and measures are provided. The chief results are showed as follows:1. As a whole,Pollutants contents from A layer in sediments are generally significantly different with those of B and C layer. Pollutants contents from the former are significantly higher than the latter. Consequently,A is vital layer while sediments controlled. Pollutant contents in interstitial water are a lot lower than sediments. Substances in sediments are constrained in a large scale,so few are out.2. In the view of pollutants or nutrient elements in the sediments,heavy metals such as As,Cd and Pb were found to be relatively;TN (total nitrogen),TP (total phosphorus) and TOC (total organic carbon) are high;there are not apparent PCBs (polychlorinated biphenyls) owing to lack of typical biotoxicity,and HCH (Hexachlorocyclohexane) and DDT (Dicophane) in organic toxic pollutants are not detected. As,Cd,Pb and TP will be critical controlled substances.3. The Study suggests that distribution of contaminated areas and contamination contents are remarkably influenced by sewage derived from major polluted upper river-River Yongdi. Many of contaminants is a little high in the entrance to River Yongdi and its near downstream,i.e.,the scope between Yonghui 05 and Yong 1009. Especially the point of 2-1,the highest concentrations of a few kinds of pollutants peak here. Simultaneously,study also indicates that pollution level is strongly affected by wind and waves. Under the strong wind and waves with high - energy,surface sediments were eroded,transferred as well as transported to relatively stable and downwind places. Whole pollution level in east reservoir exceeded that in west reservoir. Critical controlled scopes hence appeared to be the area from Yonghui 05 to Yong 1009.4. While 474m water level (frequently emerged in the recent years),management measures with respect to pollutants in-place reservoir are to be needed as follows:isolate the pollution sources oriented from upperrivers,cancelled net box fishery act and any business acts besides moon island and nearby holiday villages for reduced pollution load.5. If it is not easy available to execute that crop planting is prohibited within 479m scopes,where is belongs to the protected zone of Guanting Reservoir,retaining it is all right. It should execute natural or organic agriculture,production pattern rather than using any fertilizers and spraying any p...
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