山仔水库富营养化与水华爆发的水文因素分析

Analysis on Hydrological Factors for Eutrophication and Algae Bloom in Reservoir

文章通过水质主要指标的时空变化及其与水库流量、水位、水滞留时间等关系,研究水动力条件对山仔水库富营养化的影响。研究表明,由于山仔水库蓄水时清库不彻底,总氮、总磷浓度较高,从1997年开始呈现下降趋势,2001年后又有所回升;水库水滞留时间大于2周的年份,相对年均水位低,水库水华爆发的几率大;水库的进口、支流入口的总磷、COD、藻类数量和叶绿素a相对较高;山仔水库与下游塘坂水库因其水库形态、库容、水力交换能力的差异,藻类数量和叶绿素a含量也存在明显的差异,说明了山仔水库水华的发生与水文因素关系密切。

The effects of hydrodynamics factors on the eutrophication of Shanzi reservoir in Fujian are analyzed by taking the spatiotemporal change in water quality, flow velocity, water level, and retention time into account. The results showed that the concentrations of nitrogen and phosphorus in water were declined from 1997 to 2000,however,they have been slowly rising since 2001 owing to the wood and shrub submerged under water,and that in the years when the retention time of water in the reservoir was over 2 weeks and the water lever was low, the frequency of algae bloom was higher than other years. The concentrations of phosphorus, COD, algae and a-chlorophyll are markedly high in the input rivers. The differences between Shanzi reservoir and Tangban reservoir located downstream in geometry, volume, velocity of flow, contents of algae and a-chlorophyll, indicate that the algae bloom in Shanzi reservoir is in close relationship with the hydrodynamics factors.