太湖目前主要存在的问题是:①1998年太湖达标排放以来北太湖地区与梅梁湾的水环境没有如预期的那样得到显著改善;②太湖地区的洪涝问题并没有消除,相反随着经济的发展,其易损性增加;③东太湖的沼泽化与富营养化日趋严重,极大地降低了湖泊泄洪能力与供水能力。东太湖的沼泽化与富营养化与养殖业的无计划发展有很大关系,主要是管理所造成的。洪涝问题则是由于流域下垫面的急剧变化导致洪峰提前和洪峰流量增大。

Taihu Lake is a large shallow lake located in the Changjiang River Delta.It is con-fronting with three major issues:(1)Deterioration of water quality without any significant improve-ment since the control of drainage of wastewater taken in the end of1998;(2)the flood risk did not eliminate but rather the fragility increases with the development of economy;and(3)devel-opment of swampiness and eutrophication in eastern Taihu greatly reduces the ability of flood drainage and water supply.The reasons accountable for these problems have been addressed.Lack of estimates about changes in composition of pollution sources causes the failure of control of wastewater discharge,especially the inadequate drainage control mainly against the point source from industry as the contribution from domestic and agricultural pollution might increase and exceed the industrial pollution.In eastern Taihu,the densely developed pen-fish-culture caus-es increase in bait input,which in turn leads to the increase in nutrient deposition in lake bottom and makes it become internal loading.The excessive development of pen-fish-culture also affects the harvesting of aquatic plants,which speeds up marsh development in eastern Taihu and re-duces the flood drainage ability.The problem associated with flood is attributed to dramatic changes of underlying surface,leading to the advancement in peak flood and increase in peak flood discharge.Finally,a conceptual model of lake management is suggested for this specific lake.