淀山湖富营养化进程及水生态效应研究

Study on Eutrophication Process and Water Ecological Effect of Dianshan Lake

基于淀山湖30余年主要水质参数分析表明,2008年是湖泊水体TN、TP和chl.a变迁的重要节点,TN、TP和chl.a由逐步上升转变为稳步下降,至2018年,TN、TP和chl.a年均浓度依次为2.51 mg/L、0.100 mg/L和14.56 mg/m3,与最高年份相比依次下降了64%,73%和61%。淀山湖生态系统响应存在显著的迟滞效应,在接下来的湖泊富营养化防控的策略上,应从流域整体着眼,保证治理的系统性,提高治理的有效性;遵守水体生态修复规律,优化现有生态环境动态监测体系,指导水体生态修复途径和措施。

Since the first outbreak of water bloom in Dianshan Lake in 1985,a series of water environment control measures have been taken to improve the water quality,and remarkable results have been achieved.In this study,the main water quality parameters of Dianshan Lake for more than 30 years were summarized and analyzed,and the development characteristics of the eutrophication of Dianshan Lake were discussed.The results show that the eutrophication of Dianshan Lake has experienced two processes of aggravation and slowdown.The year of 2008 is an important node for the development trend transformation of TN,TP and Chl.a.Before 2008,TN,TP and Chl.A all increased gradually,and decreased slowly after 2008.By 2018,the average annual concentration of TN was 2.51 mg/L,the average annual concentration of TP was 0.100 mg/L,and the average annual concentration of Chl.a was 14.56 mg/m3.Compared with the highest year,TN decreased by 64%,TP decreased by 73%,and Chl.a decreased by 61%.From the perspective of the development process of lake eutrophication,there is a significant lag effect in the response of the ecosystem of Dianshan Lake.In the next process of ecosystem restoration,we should not only focus on the whole watershed to ensure the systematicness,integrity and matching of governance,and the effectiveness of governance.It's important to abide by the law of water ecological restoration,and take a measure at one stage in the time sequence according to the principle of time-space differentiation,with different leading measures at different stages.