中文摘要：

基于2012年天目湖沙河水库逐月水质及浮游植物群落结构的监测，采用主成分分析及典范对应分析，对沙河水库水质时空分布特征及其对浮游植物群落演替的影响进行了分析。结果表明，沙河水库透明度（ SD ）、悬浮物（SS）、高锰酸盐指数（CODMn）、叶绿素a （Chl a）、总磷（TP）、总氮（TN）等主要水质因子既有明显的季节变化，也存在显著的空间分布差异，浮游植物生物量和群落结构也表现出显著的季节演替。从丰度上看，蓝藻门的席藻全年都是优势种，但冬、春季节硅藻门和隐藻门藻类丰度显著增高。从生物量上看，春季的优势种为硅藻门的针杆藻，是沙河水库水体透明度的主要影响因子。主成分分析表明，沙河水库的氮和磷具有明显不同的时间变化规律。典范对应分析表明，水温、pH、溶解性总氮、SD与藻类生物量的季节演替关系密切，蓝藻、硅藻生物量与水温、溶解性总磷呈正相关，与硝态氮浓度呈负相关。研究结果表明，天目湖沙河水库水质时空差异与浮游植物种群结构的时空分布关系密切，降低氮、磷浓度对沙河水库富营养化控制及水质的保护都非常重要，但在不同季节氮、磷的相对重要性不同。农业活动，如茶园的大面积开发及旅游业活动是影响天目湖水质的两个重要因素。

英文摘要：

Monthly investigation was made on water quality and phytoplankton community structure in Shahe Reservoir in 2012 .Temporal and spatial distribution characteristics of water quality and its effect on phytoplankton community succession were analyzed through principal component analysis and canonical correspondence analysis .The results indicated there was a close relationship between the temporal and spatial differentiation of water quality and distribution of phytoplankton community structure .Obviously seasonal and spatial variations were observed in water quality factors such as transparency , suspended solids , permanganate index , chlorophyll a , total nitrogen and total phosphorus in Shahe Reservoir .Meanwhile , phytoplankton biomass and community structure were also presented significantly seasonal succession , which was closely related with temperature , pH, dissolved total nitrogen and transparency based on the canonical correspondence analysis , with the biomass of cyanophyta and bacillariophyta positively correlated with temperature , dissolved total phosphorus and negatively correlated with nitrate .Synedra was the dominant species in spring in terms of phytoplankton biomass and also the key impact factor for transparency in Shahe Reservoir.The abundance of phytoplankton was dominated by phormidium in 2012, and the abundance of bacillariophyta and cryptophyta significantly increased in winter and spring .Nitrogen and phosphorus also showed significantly temporal variations in Shahe Reservoir based on principal component analysis , and the effects of nitrogen and phosphorus on water quality varied in different seasons .Therefore, to control water eutrophication and protect water quality , it is crucial to decline the concentration of nitrogen and phosphorus according to the temporal variations of nitrogen and phosphorus .Furthermore , highly developed tea garden and tourism in the catchments of Tianmuhu Reservoir are two important factors influencing water quality .