福建省山仔水库富营养化特征

通过水质主要指标的时空变化以及气象、水文条件等因素,研究山仔水库富营养化特征。研究表明,山仔水库1997~2005年年平均质量浓度总氮为0.59~2.89mg/L,总磷为0.035~0.063mg/L,总氮、总磷从1997年开始呈现下降趋势,2001年后又有所回升,水库的进口、支流入口的总磷、总氮、COD、藻类数量相对较高。在1年内藻类种群冬、春季以硅藻为主,其余季节以蓝藻为主,水花微囊藻为优势种群持续的时间最长,每年的春末、秋初有2个藻类生长的高峰期。枯水年份水库水体滞留时间长,水力交换能力差,是导致2000~2004年水库水华频繁暴发的主要原因。

Eutrophication characteristics of Shanzi Reservoir in Fujian province

The characteristics of eutrophication in Shanzi Reservoir were studied through the spatial and temporal variation of water quality indices and meteorological and hydrological conditions. The average concentrations of total nitrogen and total phosphorus in Shanzi Reservoir from 1997 to 2005 were, respectively, 0.59 - 2.89mg/L and 0.035 - 0.063mg/L. These concentrations declined from 1997 to 2000, then rose slowly from 2001 onward. The concentrations of total nitrogen and total phosphorus, COD and algae were higher in some areas of Shanzi Reservoir, like inlets of the reservoir and input areas of branches, than in others. The dominant species of phytoplankton changed from season to season, Baeillariophyta species in spring and winter and Cyanophyta species in other seasons. Microcystis flosaquae predominated for a longer time than others. There were two annual peaks for algal blooms, late spring and early autumn. The causes.of frequent algal blooms from 2000 to 2004 were long retention time and low water transportation capacity in dry years.