中文摘要：

流溪河水库是一座位于北回归线上的大型山谷型水库,典型的热带-亚热带过渡区水体。为了解该水库的营养盐动态特征,于2008-2009年对水库的营养盐状况和环境因子进行了逐月监测,分析了其丰水年（2008）和枯水年（2009）营养盐动态的动态特征和影响因素。两年的降雨量分别为2 660 mm和1 583 mm,降雨主要集中在季风期（4-9月）。丰水期初期（4-5月）是全年营养盐浓度最高的时期,该时期丰水年与枯水年的营养盐空间分布相似：营养盐浓度沿入库河流至水库大坝方向递减,地表径流带来的外源输入是这个期间营养盐变化的主要因素。河流区的营养盐主要受地表径流带来的外源输入的影响,湖泊区营养盐主要受水位变化导致的内源输入的影响。较大的降雨量差异导致两年不同的营养盐季节动态,丰水年有着更高的营养盐水平,更小的DIN/TN与DIP/TP值。河流区较高的营养盐水平会带来湖泊区较高的TN浓度,但不会导致湖泊区更高的TP浓度。

英文摘要：

Liuxihe reservoir, located at the tropic of Cancer, is a large valley-type reservoir. In order to understand its nutrients dynamic, main nutrient variables and environmental factors were observed monthly in 2008-2009, and the variation of nutrients dynamics was analyzed. The precipitation of these two years was 2 660ram and 1 583mm, which mainly occurred in the monsoon period （April to September）. At the beginning of wet season （April and May）, all nutrient concentrations were significantly higher than other period, and the spatial distribution of nutrients showed similar character in the both high flow year and low flow year. The longitudinal pattern of nutrient concentrations was typical as follows as rivefine zone 〉 lacustrine zone, It confirmed that surface runoff was the main path for nutrient loading into the reservoir. The nutrients of riverine zone is mainly impacted by the external inputs produced by surface runoff, and the nutrients of lacustrine zone is affected by the internal recycal which depended on the variation of water level. The difference of precipitation in these two years lead to the difference of nutrient dynamic, high flow year has higher nutrient concentration, and lower DIN/TN and DIP/TP ratio. High nutrient concentration of riverine zone lead to higher TN concentration of lacustrine zone, but not caused higher TP concentration of lacustrine zone.