太湖沼泽化评价方法的建立及应用

A method for assessing the swamping of Lake Taihu and its application

为了研究太湖的沼泽化现状,在考虑太湖生态类型空间分布多样性特征的基础上,遵循以水生植物为主、促淤效应为辅的沼泽化评价原则,选取水生植物类型、水生植物生物量、沉积速率、平均水深为指标,构建了沼泽化定量评价体系,并对太湖沼泽化综合指数进行分湖区计算.结果表明,太湖沼泽化程度可分3个水平:处于沼泽化盛期的东太湖,其沼泽化综合指数为2.81,为全湖最高;处于沼泽化前期的东部滨岸区、贡湖和南部沿岸区,其沼泽化综合指数分别为1.36、1.19、1.18;不存在沼泽化问题的梅梁湾、西部沿岸区及湖心区,其沼泽化综合指数分别为0.90、0.79、0.05.对沼泽化程度严重的东太湖有必要采取人工生物量控制、生态清淤、围网养殖规划等减缓沼泽化进程的治理措施.

Lake Taihu,a large shallow lake,has swamping trends in different zones,especially in Dongtaihu Bay.In order to quantitatively evaluate the extent of swamp formation in Lake Taihu,indexes of characteristics such as dominant macrophyte community,macrophyte biomass,deposition rate,and average depth were selected and combined into a comprehensive index.Due to a significant spatial discrepancy in the ecological structure of Lake Taihu,the study area is divided into seven zones.The results show that the swamping extent of Lake Taihu could be assigned to three levels：Dongtaihu bay is in heavy swamping and the comprehensive index is 2.81;the east epigeal zone,Gonghu bay and the southwest zone are in mild swamping and their comprehensive indexes are 1.36,1.19,and 1.18 respectively.Swamping does not occur in Meiliang bay,the northwest zone and the central zone,where the comprehensive indexes were 0.90,0.79 and 0.05 respectively.It is necessary to take effective measures such as controlling the macrophyte biomass,ecological dredging and designing the layout of enclosures to slow down the deteriorating tendency to swamp formation in Dongtaihu bay.