%0 Journal Article %T 长江流域近50年降水变化及其对干流洪水的影响 %T Changes in Rainfall and Flood Frequency in the Yangtze Basin:1960-2001 %A 任国玉 %A 陈正洪 %A 杨宏青 %A REN,Guoyu %A CHEN,Zhenghong %A YANG,Hongqing %J 湖泊科学 %J Journal of Lake Sciences %@ 1003-5427 %V 15 %N Z1 %D 2003 %P 49-55 %K 长江流域;降水;面雨量;暴雨日数;气候变化;洪水事件 %K Precipitation;area rainfall;heavy rain;flood;climate change;Yangtze River basin %X 根据我国长江流域气象观测站近42年的资料,分析了整个流域年和季节平均面雨量、暴雨日数和暴雨量的变化特征,以及降水对流域径流和洪水的影响.长江流域年和夏季平均面雨量存在明显的年际和年代变化特征,也表现出比较显著的趋势变化特点.大部分测站年平均面雨量呈增加趋势,夏季和冬季平均面雨量的增加趋势尤其明显;秋季平均面雨量呈显著下降趋势.同时,年和夏季暴雨日数和暴雨量也在较大范围内呈显著增加趋势.长江流域的降水对干流平均流量具有重要影响.1973年、1983年和1998年的洪水主要是由明显高于平均的流域面雨量引起的;长江下游平均流量变化趋势也同流域年平均面雨量、夏季平均面雨量变化趋势基本一致,特别是70年代末以来,下游平均流量和流域面雨量的上升趋势更加明显,并同时在1998年达到最高值.长江流域大的丰水年一般对应El Nino年或El Nino次年,表明E1 Nino对长江较大洪水可能具有一定影响. %X A data set of more than 100 stations was used to analyze the annual to multidecadal changes in precipitation in the Yangtze Basin for the last 42 years (1960-2001). A comparison between the rainfall changes and discharge at Datong Station was made to investigate into the influence of climate variability on floods in the river basin. In the last 42 years, the annual, summer and winter area-averaged precipitation for the basin increased, with the summer and winter increases being statistically significant. Marked increases could be seen for most stations, especially for summer and winter seasons. Autumn, however, witnessed significant decrease in the area precipitation. Meanwhile, days with heavy rain and heavy rainfall for year and summer season also increased for most stations in the middle and lower reaches of the river, and the increase for summer is significant for more stations. Good relationship between the area rainfall and runoff of Datong Station could be found, indicating an overwhelming influence of precipitation on the river discharge and floods. The three largest floods (1973, 1983 and 1998) all occurred in the exact years with the highest area rainfall for the period analyzed. The up-going tendencies of the Datong discharge and area rainfall for the last 42 years are similarly significant, especially for summertime and for the last 20 years or so. Both of them reached to the highest values in 1998 when the severest flood of the period led to a huge loss in property and lives. It is interesting that the major foods of the river well correspond to the ENSO events in the eastern tropical Pacific. %R 10.18307/2003.sup06 %U http://www.jlakes.org/ch/reader/view_abstract.aspx %1 JIS Version 3.0.0