东太湖水环境质量调查及保护对策

WATER QUALITY AND ITS PROTECTION IN LAKE EAST TAIHU

根据1991年2月～1994年10月对东太湖的水质监测，分析了东太湖水质现状、变化及发展趋势，并提出一些保护水质的对策。结果表明，东太湖存在三种营养类型，即中、中一富、富营养型，湖水中TN、TP、BOD5、CODMn、Chla、NH3-N各月均借分别在0．27－2．46、0．014－0．025、0．37—1．91、1．49－5．11、1．36－7．28（mg／m3）、0．01－0．42mg／L之间变化；CODMn、PO4-P较60年代初有所下降，NH3－N有所升高，TN、TP与80年代初比较，变化不大。适当网围养鱼对东太湖水质影响不大，相反可延缓东太湖的沼泽化和富营养化进程。

Based on the water quality investigation in Lake East Taihu from 1991 through 1994, analysis was carried out on the present water quality and its change trend, and some protection measures were suggested. Three trophic levels (eutrophic, meso-eutrophic and mesotrophic) existed in the lake in different seasons. The whole lake mean yalue of the following water qua1ity parameters ranged as: TN, 0.27-2.46 mg/L;TP, 0.014-0.025mg/L; BOD, 0.37-1. 91mg/L; COD, 1 .49-5. 11mg/L; Chla, 1 .36-7.28mg/m3; and NH4, 0.01-0.42mg/L. Since 1960, remarkable decreases in COD and PO4 have occured, and the NH4 content has increased slightly. No distinctive changes in TN and TP were detected after 1980. It means that moderate scale penculture may prevent the lake from eutrophica tion and swampiness.