【摘要】 叶绿素a是浮游植物均具有的光合色素,是评价水环境质量的重要指标之一。以叶绿素a为指示性指标对冰封期和非冰封期叶绿素a及相关环境因子含量指标进行了监测,以了解乌梁素海水体叶绿素a在治理前后(2014-2017年)在时间和空间上的分布变化特征及影响因素,尤其是针对寒区湖泊的特点,对冰封期叶绿素a、总氮、总磷的时空分布进行了深入分析,运用相关性分析和逐步回归分析方法探讨了叶绿素a与理化环境因子的关系。结果表明,绿素a总体上呈冰封期高于非冰封期的特征,2014-2016年叶绿素a呈逐年递减趋势,但2017年又略有回升,且区域性差异显著,与氮磷营养盐空间分布趋势一致,表现为湖北区总排干入水口附近大于湖心区和湖南区。影响乌梁素海的主要水化学因子依次为总磷、溶解氧、溶解无机磷、总氮、正磷酸盐、总溶解性固体;同时,透明度与叶绿素a呈极显著负相关;冰层厚度因其影响冰下水体污染物的蓄积,也是影响水域环境的关键因素。总体上,治理后叶绿素a较治理前有明显的下降趋势,表明湖北区总排干入湖水的污染物得到了有效控制,对乌梁素海水体污染控制与修复取得了一定成效,同时也显现出乌梁素海冰封期水体由于水体冻结使得污染物析出,致使冰下水体富营养化较其他时期严重。更多还原

【Abstract】 Chl.a as a photosynthetic pigment of phytoplankton has been used for one of the important indicators to evaluate the quality of water environment. To get a better understanding of the spatial and temporal distribution of Chl.a and its influencing factors, Chl.a and its related environmental factors were monitored in Lake Ulansuhai from 2014 to 2017 before and after the lake environment governance. The spatial and temporal distribution of Chl.a, TN, and TP was studied. The relationships between Chl.a and the related physical and chemical environmental factors were analyzed through the correlation analysis and the stepwise regression analysis. The results showed that Chl.a was higher in the ice-sealed period than that in non-ice-sealed period. However,Chl.a showed a decreasing trend from 2014 to 2016 except for a slight increase in 2017. But it changed significantly from the north to the south lake areas where were near the intake in the north area, the concentrations of Chl.a, TN, and TP were higher than that in the central and the south areas. The main aquatic chemistry factors affecting the lake environment were TP, DO, DIP, TN, DTP, and TDS in turn. Transparency was negatively correlated with Chl.a and ice thickness was also one of the key factors affecting the water environment. In a word, Chl.a had decreased significantly after governance in the whole area of the lake. This indicated that as the pollutants discharged into lake water the intake were effectively controlled, the pollution of Lake Ulansuhai water body had been controlled and remediated to some extent although the eutrophication degree in the water body under the ice was more serious during the ice-sealing period than that in the other seasons.更多还原