生态疏浚对太湖五里湖湖区生态环境的影响

五里湖作为太湖富营养化最严重的区域,内源污染和生态退化成为困扰五里湖最主要的两个问题.生态清淤工程的特点是对所要疏浚污染底泥污泥厚度通过采样分析后精确测定,并且在施工过程中的控制精度也高于一般的工程疏浚.所以生态清淤既可以清除五里湖的内源污染,又能为其生态恢复创造条件.本文通过对五里湖生态疏浚对生态系统的影响,疏浚区底泥、水质质量的改善的效果以及对原位培养生物的抗氧化系统组分变化等多个方面进行分析评价,发现,五里湖生态疏浚区底泥中磷含量下降了30%,左右,重金属含量升高的地质积累指数小于1级.疏浚后半年内水体中总磷和溶解磷含量比疏浚前下降10%-25%左右,叶绿素a含量下降40%,左右,其它水质理化参数保持正常.作为生物标志物原位培养生物的抗氧化系统组分在疏浚前后变化较小所以认为,五里湖疏浚达到了一定的效果,并且控制了对生态的压力,为下一步生态修复创造了条件.

Analysis of the Influence of the Ecological Dredging to Ecosystem of Lake Wuli, Lake Taihu

Wuli Lake is the most contaminative part of Taihu lake hecause of the endogeneous contamination and ecological degeneration. They liiust prepare for the resume of the ecosystem as the dredging eliminates the endogeneous contamination. To accessing some aspects such as changes in sediment and water, influences of ecosysleDi and ingredients of antioxidant systems of snails in fields, we found:the total phosphorus in sediment decreased about 30%, Geological acumination index(I_geo) of the heavy metals did not exceed 1 grade, the TP and soluble phosphorus in water decreased about 10%-25%, the concentration of Chi a in water decreased about 40%, else parameters of water quality kept in gear. The changes of ingredients of antioxidant systems are in low ecological risk range. Therefore, we considered the dredging in Wuli Lake achieved some effects, conlrolled the pressure to ecosystem, created good conditions for the following ecological resume.