中文摘要：

通过分析1957-2008年长江与鄱阳湖相互作用的基本特征及其与长江中游、鄱阳湖流域的径流量和气候变化的关系,并用2004-2006年三峡水库蓄水、放水量的数据,定量地计算和比较了三峡水库运行和区域气候变化对长江与鄱阳湖相互作用的影响程度,得出如下主要结论：1）从年际、年代际尺度上来看,鄱阳湖流域的气候变化和五河入湖流量是鄱阳湖水位和水量变化的主要因素,同时也在很大程度上决定了长江与鄱阳湖相互作用关系及其强弱变化。2）长江与鄱阳湖的相互作用强度是此消彼长的关系。从季节来看,鄱阳湖对长江的较强作用主要在4-6月,而长江对鄱阳湖的较强作用主要发生在7-9月。3）三峡水库运行并没有改变长江与鄱阳湖作用的基本特征,在多数季节三峡水库的影响不足以解释长江径流量变化的10%,但是水库在不同季节的蓄水或放水在一定程度上影响了江湖作用的季节变化和鄱阳湖流域的旱涝机率。4-6月的放水加强了长江作用,由于此时正值鄱阳湖流域的雨季,增强的长江作用在湿润气候的环境下可能增加初夏鄱阳湖流域发生洪涝的概率;7-9月的少量蓄水则减弱长江对鄱阳湖的作用,降低了湖区洪涝的概率;而10月份三峡水库的大量蓄水可能增加鄱阳湖流域的旱季干旱发生率。

英文摘要：

Interaction of the Yangtze River and the Poyang Lake strongly affects the Poyang Lake water resources and flood and drought potentials in the lake basin. This interaction and its variation are examined in this study for the period 1957-2008. In addition, changes in the relationship between the Yangtze River and Poyang Lake after the operation of the Three-Gorge Dam （TGD） are evaluated using the TGD operation data available for 2004-2006. Major findings are shown as follows. 1） At interannual to decadal timescales the variation in the Poyang Lake water level is primarily determined by fluctuations of the climate and the inflow from the five major tributaries in the lake basin. By influencing the lake level these fluctuations also affect the lake-river interaction. 2） At the seasonal timescale, the Poyang Lake has the largest outflow to the Yangtze River and exerts a strong pressure on the mainstream during April-June, when the lake receives annual peak inflow from its tributaries. The Yangtze River＇s blocking and/or reversed flow to the Poyang Lake are the strongest during July-September. 3） The operation of the TGD has changed little in terms of seasonal variations of these lake and river forcings. In most of the seasons, the influence of the TGD has resulted in less than 10% of the variation in the Yangtze River flow. However, by damming or releasing water, the TGD can result in seasonal changes in the Yangtze River flow and river-lake interactions. These subtle effects from the TGD operation are quantified and compared to the climate effect on the river-lake interactions. These comparisons show enhancement in some seasons while weakening in the other seasons of the climate effect on river-lake interactions and flood or drought potential in the lake basin by the TGD operation.