淀山湖富营养化控制叶绿素a基准研究初探

RESEARCH ON CHLOROPHYLL A CRITERIA ESTABLISHMENT IN DIANSHAN LAKE

水质基准是制定水质标准的重要依据,研究以淀山湖为例,基于淀山湖二十多年来的监测数据,通过数据分析的方法,探讨了淀山湖叶绿素a基准取值方法。结合淀山湖叶绿素a变化趋势与年内分布特征,通过参照状态法,将叶绿素a分为冬春季节与夏秋季节两个时期,建议冬春季节基准值为2.0μg/L,夏秋季节基准值为5.0μg/L。并参考太湖总磷推荐基准值,利用淀山湖总磷与叶绿素a投入响应关系,对获得的基准值进行了初步验证。

Ambient water quality criteria are the important basis for establishing water quality standards, and the signifi- cant part of scientific water quality management system. The Dianshan Lake is an important water resource located in the upstream of the Huangpu River. Its water quality directly affects the quality of the drinking water in Shanghai. Since the first algal bloom in 1985, the ecosystem in 1985--1992 is not a healthy but relatively stable compared with that other pe- riods. To protect the lake and fulfill its designated uses, this research developed a water quality criteria based on the change of Chl.a in the recent 23 years. On inter-annual variation the concentration of Chl.a in the lake can be divided into four periods： relatively stable, slow rise, rapid increase and slow down. Analysis by the temporal reference state and the fre- quency distribution methods suggested that Chl.a should be divided into winter-spring and summer-autumn on season variation. The recommended criteria value of Chl.a in winter-spring time and summer-autumn time were 2.0 μg/L and 5.0 μg/L, respectively, which were validated using the input-response relationship referring to the TP criteria of Taihu lake.