滨海地区混盐水体叶绿素a特征及影响因子分析

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

为研究滨海地区混盐水体富营养化问题，以天津滨海地区典型混盐景观水体一清净湖景观水体为研究对象，根据2013年3—9月水质监测数据，研究其叶绿素a在含盐量为0．05％～3％混盐环境下的动态特征及显著影响因子。结果表明，清净湖水体中叶绿素日浓度变化范围为2．06-358．15μg，L，呈夏秋季高、春季低，峰值主要集中在6-9月，其变化受多个环境因子共同影响，与水温、透明度、高锰酸盐指数和总磷显著相关，而与pH值、溶解氧、总氮和矿化度相关性不显著。通过多元逐步回归分析，进一步确定磷是清净湖景观水体藻类生长的主要影响因子。因此，清净湖景观水体富营养化防治重点时段应为6-9月，蓟运河故道应为重点防治水域，控制水体中磷含量应为防治工作的重点。

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 p.g/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.