Analysis of Dynamic Feature and Influencing Factor of Chlorophyll-a in Mesohalinous Water in Coastal Area

Taking a typical landscape water Qingjing Lake in Tianjin as the research object,the eutrophication problem of mesohalinous landscape water in coastal area was studied.Based on the monitoring data of chlorophyll-a concentration and water quality from March to September 2013,the dynamic change of chlorophyll-a concentration was analyzed,and correlation analysis between chlorophyll-a concentration and its influencing factors were made.Result showed that the variation range of chlorophyll-a concentration was 2.06 ~358.15 μg/L,and had a high level from June to September.Chlorophyll-a concentration was affected by some influencing factors together.Between the chlorophyll-a concentration and water temperature,diaphaneity,CODMn,TP displayed significant positive linear correlations,but not significantly related with pH,DO,TN and degree of mineralization.Multiple stepwise regression analysis results showed that phosphorus was the key controlling factor of the landscape water consisted of Qingjing Lake and old Jiyun River course.It was suggested that the eutrophication control of the Lake should be emphasized from June to September,with dropping of phosphorus concentration as the focus.