小型人工湖泊水环境变化特征分析及驱动因子识别

小型人工湖泊能够改善城市水生态环境,但其易受外界环境的影响而使水体发生污染。为了探析小型人工湖泊水质和底泥中污染物的变化特征及引起水质污染的主要驱动因子,以郑州大学新校区的眉湖为例,结合现场监测与实验室检测数据,分析了水质和底泥中污染物的变化特征及作用机制;在分析水质影响因子间相关关系的基础上,通过主成分和主因子分析识别了影响小型人工湖泊水质的主要驱动因子,即透明度、水温、p H值、电导率、氧化还原电位、叶绿素a、藻类、流速、总磷和总氮。

Identification of the influential factors and analysis of the varying characteristics for the water environment of the small artificial lakes and pools

The paper is inclined to present its study on the identification of the motivating factors and analysis of the varying characteristics for the water environment of the small artificial lakes and pools by taking Meihu Lake of the new campus,Zhengzhou University as the research goal.We have first of all analyzed the variation characteristics and interaction mechanism of all kinds of pollutants in the water in combination with the field monitoring and laboratory detection data.Secondly,we have analyzed the correlation between the influential factors concerned with the principal component analysis and principal factor analysis method.And,finally,the results of our investigation and analysis indicate that the water pollutant constituents of BODs and CODCr can be categorized into class Ⅲ or above as mentioned above in section Ⅰ,Ⅱ and Ⅲ,rather not into class Ⅲ in section Ⅳ and Ⅴ or to the sampling point 0#.As for the TP concentration rates,they belong to class Ⅳ or below,whereas the TN content concentrations,they should be categorized into class Ⅲ or above in each monitoring section.Though the water quality content concentrations of NH3-N and NO3--N in each monitoring section can be stated in a good condition,the turbidity in section Ⅰ,Ⅱ and Ⅲ tends to be higher than that of section Ⅳ and Ⅴ.Moreover,the DO concentrations belong to class Ⅰ in each monitoring section,whereas the concentrations in section Ⅲ and Ⅳ should be put into higher grade than those of sections Ⅰ,Ⅱ and Ⅴ.In addition,the electrical conductivity in section Ⅴ can be regarded as better than those in other sections,with the contents of chlorophyll-a going up to the eutrophic state in section Ⅰ and Ⅱ since the mid-May afterwards.As the sediment of Meihu Lake is concerned,the water pollutant concentration rates of TN and NH3-N assume a trend of declining,while the TP content concentration rates present a trend of slight increase in section Ⅱ,though the rates of TP,TN and NH3-N reveal a trend of increase in section Ⅲ.At the same time,the situation of chlorophyll-a and algae pollution revels a better correlation among SD,turbidity,DO,TN,NH3-N and NO3--N.The chlorophyll-a and algae have a negative correlation for SD and DO,but there exists a positive correlation for turbidity,TN,NH3-N and NO3--N.Thus,it can be concluded that the main factors affecting the water quality of Meihu Lake can be illustrated as SD,water temperature,pH value,the electrical conductivity,the oxidation reduction potential,Chl-a,algae,flow velocity,TP and TN,and so on.