【摘要】 本文在分析洞庭湖水质现状及现有污染源的基础上,选择COD_Mn、TN、TP作为水质敏感参数,对疏浚前后洞庭湖水环境容量的变化情况进行了模拟计算．结果表明,疏浚工程的实施增加了洞庭湖的水环境容量,水位越低、流量越大,增加值越多．分析认为．疏浚使得洞庭湖区河道贯通、水流归槽、流量流速加大,增强了污染物稀释自净能力．在外源不变的情况下,对洞庭湖的水质改善起到了积极的作用,一定程度上缓解了湖泊的富营养化状况．更多还原

【Abstract】 Lake Dongting,which is the second biggest fresh water lake in our country,is located in the middle rea- ches of the Yangtze River.For a long time,the Yangtze River and the other four riverways which inpour in Lake Dongting always take a great deal of sands every year,as a result,the lake was filled up,many continents were de- veloped,the water velocity was slowed and the water environmental quality was worsened.In order to resolve these problems,dredging engineering is actualizing in Lake Dongting now.Combined with the engineering,the changes in COD_Mn,capacity,TN capacity and TP capacity of Lake Dongting before and after dredging were simulated based on the analysis of the Lake Dongting actuality water environmental quality in the paper,and the reasons were also analyzed.It was found that dredging engineering enhanced the water environmental capacity of Lake Dongting.Es- pecially in the lower water and higher flux,the water environmental capacity increased more.Under the same source of explicit pollution,the dredging was helpful for improving the water quality of Lake Dongting,and it could ameliorate the eutrophic state of Lake Dongting in a certain extent.更多还原