粤东三个中型水库富营养化特征分析

Eutrophication analysis of three medium reservoirs in the eastern of Guangdong province

于2000年的丰水期和枯水期,对粤东三个中型水库:合水水库、河溪水库、沙田水库进行了富营养化特征进行了调查与分析。结果表明:三个水库多数采样点处于中营养阶段;总氮在0.16～1.58mg·L^(-1)范围内,总磷为0.034～0.15mg·L^(-1)叶绿素则为0.732～6.57mg·m^(-3);浮游植物大部分是中污性至寡污性的种类,以蓝藻、绿藻种类占优势,常见种是微囊藻(Microcystis sp.)、颗粒直链藻(Melosira granulata)、梅尼小环藻(Cyclotella meneghiniana)。合水水库和河溪水库的富营养化水平较高,TSI指数在40左右,丰水期的富营养化水平高于枯水期;而沙田水库的富营养化水平相对要低,TSI指数在30左右,丰水期的富营养化水平要低千枯水期。说明这三个水库受流域的影响程度不同。

The eutrophication of three medium reservoirs locating in the eastern of Guangdong Province: Heshui reservoir, Hexi reservoir and Shatian reservoir, was investigated in flood season and dry season of 2000. The results showed that the three reservoirs were mesotrophic. The concentrations of total nitrogen, total phosphor and chlorophyll a in the three reservoirs were in ranges of 0.16 -l.58mg·L-1, 0.034 - 0.15mg·L-1 and 0.732 - 6.57mg· m-3, respectively. Microcystis sp. , Melosira granulate and Cyclotella meneghiniana were the dominant species. The trophic status indices (TSIs) of Heshui reservoir and Hexi reservoir were nearly 40, higher than that of Shatian reservoir, which were around 30. The seasonal dynamics of trophic status index is different among the three reservoirs. In both Heshui reservoir and Hexi reservoir, the TSIs were higher in the flood season than in the dry season. In contrast, the TSIs of Shatian reservoir were lower in the flood season than in the dry season. The difference in the seasonal dynamics between the reservoirs indicated that watershed has varied impacts on the eutrophication of the three reservoirs.