滴水湖水体叶绿素a与水质因子的多元分析

Multianalysis between chlorophyll a and other environmental factors in Dishui Lake

摘要:

根据2009年1月-2009年12月间对滴水湖叶绿素a含量及pH、水温、溶解氧、透明度、总磷、总氮、高锰酸盐指数等水质因子的调查结果，分析了叶绿素a的时空分布及各站点叶绿素a含量与各水质因子的相关关系，并建立逐步回归多元线性方程。结果显示：2009年滴水湖叶绿素a含量均值为（52.97±28.32） mg/m³，变化范围为（0.5～139.5）mg/m³，4-6月出现峰值。站点Ⅲ与站点Ⅳ、Ⅴ、Ⅵ的叶绿素a含量差异极显著，站点Ⅰ与站点Ⅵ的差异极显著，其他各站点之间差异不显著。各站点叶绿素a含量与水质因子关系比较复杂，在不同的监测站位，对叶绿素a含量有显著影响的水质因子各不相同，逐步回归方程的入选因子也各有差异。取对数进行相关性分析得到lg(Y_Chl.a)与lg(X_TP)呈极显著正相关，与lg(X_TN/TP)呈显著负相关，据此建立的相关方程分别为：lg(Y_Chl.a)=2.146+0.530lg(X_TP)，lg(Y_Chl.a)=2.017－0.275lg(X_TN/TP)，该方程较逐步回归方程在实践中更有指导意义。

Abstract:

In this paper, the correlation between chlorophyll a and some environmental factors including pH, temperature, dissolved oxygen, transparency, total phosphorus, total nitrogen, chemical oxygen demand and so on, was analyzed by regression statistical method, based on the investigation data in Dishui Lake from January to December in 2009. The spatial and temporal distribution characteristics of chlorophyll a were also analyzed.The results showed that the concentration of chlorophyll a ranged from 0.5 to 139.5 mg/m³ with the average value of （52.97±28.32） mg/m³.The highest concentration occurred in the period of April to June. Extremely significant differences of chlorophyll a existed between sampling site Ⅲ and VI, V, VI respectively and also between sampling site I and VI. In different sampling sites, the important environmental factors affecting chlorophyll a were different, thus different factors were chosen for the multiple stepwise regression. However, the relationship between lg(Y_Chl.a) and lg(X_TP) was positive, while that between lg(X_TN/TP and lg(X_TN/TP) was negative. The equations obtained were lg(Y_Chl.a)=2.146+0.530lg(X_TP)，lg(Y_Chl.a)=2.017－0.275lg(X_TN/TP), which were more practicable than the multiple stepwise regression equations.