中文摘要：

为了解千岛湖在大量放养鲢鳙鱼后叶绿素a的时空分布格局及其与主要环境因子的相关性,本文于2007年1月至2009年12月对千岛湖叶绿素a及其他10个水质理化指标进行了每月定期采样及监测.结果表明：上游河流区和过渡区叶绿素a含量存在明显的季节变化,其共同特点是每年会形成春季和夏末秋初的双高峰.叶绿素a含量在空间分布上具有一定的分异性,河流区叶绿素a含量明显高于中下游区（过渡区和湖泊区）.叶绿素a含量的最高峰通常出现在4-12m,最深出现在20m,春夏季出现明显分层.千岛湖叶绿素a与亚硝酸盐氮（NO2-N）、高锰酸盐指数（CODMn）、水温（WT）和硅酸盐（SiO23-）呈低度相关,与其他环境因子无显著相关性或相关性很弱.多元逐步回归分析结果显示,千岛湖叶绿素a与筛选出的几个关键环境因子之间的回归方程为：Chl.a=0.114WT＋2.120CODMn＋17.157SiO32--37.391NO2-N-1.946.

英文摘要：

The temporal and spatial distribution patterns of chlorophyll-a and its correlation with the main environmental factors were analyzed according to the monthly investigation from January,2007 to December,2009 in Lake Qiandao where a large number of silver carp and bighead carp stocked.Results showed that the concentration of chlorophyll-a in sampling stations located in the upper reach riverine and transitional zones of the reservoir showed a significant seasonal variations with two concentration peaks occurred in spring and late summer or early fall,respectively.The concentrations of chlorophyll-a in upstream sites（in the riverine and transitional zones） were significantly higher than those of downstream sites.The chlorophyll-a during the warm season was usually stratified with a concentration peak occurring at depths between 4m and 12m,occasionally at a depth of 20m.The result of correlation analysis showed a weak correlation between chlorophyll-a and NO2-N,CODMn,water temperature（WT） and silicate（SiO2-3）,while no significant correlations of the chlorophyll-a were found with other environmental factors,especially with the TP in the water.The regression equation between chlorophyll-a and the correlated environmental factors could be expressed through the multiple linear stepwise regressions as：Chl.a=0.114 WT＋2.120 CODMn ＋17.157 SiO2-3-37.391 NO2-N-1.946.