不同水源补给对景观水体水质及浮游动物的影响

通过定期监测由再生水补给的桃花潭和由地表水补给的兴庆湖两个景观水体中水质和浮游动物的历时变化,探究不同水源补给对水体水质和浮游动物的影响及其相关性。结果表明,桃花潭水体中TN、TP、TCOD和Chl-a浓度年均值分别为4.65、0.22、29.24 mg/L和92.81μg/L,分别为兴庆湖对应值的1.95、2.29、1.49和2.30倍,分析可知再生水补给水体TP浓度增加引起浮游藻类增加,最终导致水体TCOD浓度上升。两水体检测到轮形动物门和节肢动物门共27种,其中轮虫类21种、枝角类和桡足类各3种;桃花潭浮游动物年均生物量为0.70 mg/L,且该水体中浮游动物种数、富营养型指示种种数及生物量均大于兴庆湖的对应值。冗余分析(RDA)和Pearson相关性分析结果表明,两水体中轮虫、枝角类的生物量与水质中的磷酸盐和TP相关性强,藻类的暴发性增长对枝角类的贡献比对轮虫的贡献更大,而桡足类受影响较小。总之,TP是影响再生水补给的水体中浮游动物生物量的主导因子。

Effects of Different Water Sources Supply on Water Quality and Zooplankton in Landscape Waters

Diachronic changes of water quality and zooplankton in Taohua Pool(supplied by reclaimed water)and Xingqing Lake(supplied by surface water)were monitored regularly to explore the effects of different sources on water quality,zooplankton and their correlations.Annual average concentrations of TN,TP,TCOD and Chl-a in Taohua Pool were 4.65 mg/L,0.22 mg/L,29.24 mg/L and 92.81μg/L,respectively,which were 1.95,2.29,1.49 and 2.30 times of the corresponding values in Xingqing Lake.The analysis indicated that the increase of TP concentration in Taohua Pool(supplied by reclaimed water)resulted in the increase of phytoplankton algae,and eventually led to the increase of TCOD concentration in the water.Meanwhile,27 species of Rotifera and Arthropoda were detected in the two water bodies,including 21 Rotifera,3 Cladocera and 3 Copepoda.Annual average biomass of zooplankton in Taohua Pool was 0.70 mg/L,and the number of zooplankton species,eutrophic indicator species and biomass in the water were larger than those in Xingqing Lake.Furthermore.redundancy analysis(RDA)and Pearson correlation analysis showed that the biomass of Rotifera and Cladocera were strongly correlated with phosphate and TP in both water bodies,and the contribution of algae explosive growth to Cladocera was higher than that to Rotifera.However,Copepoda was not affected obviously by algae explosive growth.In conclusion,TP is the dominant factor affecting zooplankton biomass in water bodies supplied by reclaimed water.