淀山湖蓝藻水华高发期叶绿素a动态及相关环境因子分析

Dynamics of chlorophyll-a and analysis of environmental factors in Lake Dianshan during summer and autumn

根据2008年5-9月专项监测数据,分析蓝藻水华高发期淀山湖叶绿素a浓度的动态变化,及其与pH、溶解氧、TN、TP等环境因子的相互关系.结果表明,淀山湖蓝藻水华高发期叶绿素a存在明显的时间变化和空间分异,特别是叶绿素a的峰值共对应了3次水华暴发过程.其叶绿素a对数与总磷对数呈极显著正相关,与硝酸盐氮、TN/TP呈负相关,与总氮、氨氮等则无显著相关性;这表明淀山湖可能是一定程度的磷限制性湖泊.此外,叶绿素a与水温、pH、溶解氧呈显著正相关,与透明度存在极显著负相关.

According to the monitoring data at 13 sampling sites of Lake Dianshan from May to September 2008,the relationship between chlorophyll-a concentrations and environmental factors（water temperature,pH,DO,TN and TP） was investigated.The results indicated that there was an obvious temporal and spatial variation of chlorophyll-a.The first cyanobacterial bloom in 2008 occurred on July 23 at Qiandungang site and Youyongchang site.The most severe bloom covered a total area of 17km2 on August 27.Significantly positive logarithmic correlation was found between chlorophyll-a and total phosphorus,but not for ammonia nitrogen,nitrate nitrogen and total nitrogen.Phosphorus might be the main limited factor in Lake Dianshan.Significantly positive correlations were found between chlorophyll-a concentration and water temperature,pH,dissolved oxygen,and markedly negative correlation between chlorophyll-a and transparency.