Dong Chun-Ying, Yu Zuo-Ming, Wu Zhi-Xu, Wu Chun-Jin
School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China.
Huan Jing Ke Xue. 2013 Jul;34(7):2574-81.
Lake Qiandao is a typical subtropical man-made reservoir in China. The investigation on the seasonal and vertical dynamics of water temperature, dissolved oxygen (DO), pH value, turbidity, photosynthetic available radiation (PAR) and chlorophyll a was conducted in 2011 in order to find out the physical characteristics of Lake Qiandao. The average surface water temperature ranged from 10.4 to 32.7 degrees C. A monomictic thermal stratification was observed in Lake Qiandao, initiating in April and lasting until December. The results showed that thermal stratification had influences on vertical distribution of DO, pH value, turbidity, PAR and chlorophyll a. Very strong stratification of DO was found, inducing lower oxygen concentration in the thermocline layer and temporal hypoxia in the bottom water. The maximum turbidity was found in the thermocline layer and the precipitation affected the surface turbidity value. Moreover, the chlorophyll a concentration was higher in the surface water and lower in the bottom water as found in this study, implying that water quality was affected by stratification. Besides, the maximum photosynthesis rate and algal growth rate were found at the depth 5-10 m below the water surface. Therefore, the results can provide theoretical support for the sampling and analysis of algal blooms in Lake Qiandao.
千岛湖是中国典型的亚热带人工水库。为了解千岛湖的物理特征，于2011年对水温、溶解氧（DO）、pH值、浊度、光合有效辐射（PAR）和叶绿素a的季节及垂直动态进行了调查。表层水的平均温度在10.4至32.7摄氏度之间。千岛湖观测到单循环热分层现象，始于4月，持续至12月。结果表明，热分层对溶解氧、pH值、浊度、光合有效辐射和叶绿素a的垂直分布有影响。发现溶解氧存在很强的分层现象，导致温跃层中氧浓度较低，底层水出现暂时缺氧。最大浊度出现在温跃层，降水影响表层浊度值。此外，本研究发现表层水的叶绿素a含量较高，底层水较低，这意味着水质受到分层的影响。此外，光合作用速率和藻类生长速率的最大值出现在水面以下5至10米深处。因此，研究结果可为千岛湖藻类水华的采样和分析提供理论支持。
