淡水鱼塘叶绿素a与环境因子间影响关系的通径分析

Path analysis of interactional relationship between Chlorophyll-a and environmental factors in freshwater fishponds

为简便而有效地研究池塘水体中叶绿素a(Chl.a)含量与环境因子间的复杂关系,建立通径分析方法将各因子与Chl.a的相互影响关系清晰化。利用上海地区38批次淡水鱼养殖池塘水质监测数据,通过通径分析筛选出影响Chl.a含量变化的关键因子。结果显示:影响Chl.a含量变化的关键因子是高锰酸盐指数(CODMn)、活性磷(PO_4^--P)、透明度(SD)和溶解氧(DO);CODMn和PO_4^--P是影响养殖水体中Chl.a含量的主导因子,它们的决定系数分别为0.426和0.325,占所有关键因子决定值的89.6%;利用关键因子对Chl.a建立多元回归线性方程:Chl.a=60.17+9.90 CODMn+100.30(PO_4^--P)-1.74 SD-4.82 DO(R=0.784),并通过检验。

In order to research and clarify the complicated relationship between Chlorophyll-a(Chl.a)and environmental factors in fishpond water,a convenientand effective method of path analysis was built in this study.Water quality monitoring data from 38 freshwater fishponds in Shanghai were analyzed to screen the key factors effecting Chl.a by path analysismethod.The results showed that four environmental factors as key influence factors,which were chemical oxygen demand(CODMn),phosphate(PO-4-P),transparency(SD)and dissolved oxygen.Meanwhile,CODMn and PO-4-P were themost major factors affecting Chl.a.Thedetermining indexes of CODMn and PO-4-P were 0.426 and 0.325,respectively,which held the main determining index percentage of 89.6%among all the environmental factors.Four key factors were used to build the multiple regression equation of Chl.a,which had been verified later and the equation was:Chl.a=60.17+9.90 COD Mn+100.30(PO-4-P)-1.74 SD-4.82 DO(R=0.784).