地理学报 ›› 2000, Vol. 67 ›› Issue (5): 567-575.doi: 10.11821/xb200005006

• 论文 • 上一篇    下一篇

1990年代长江中下游地区多雨的机制分析

龚道溢1, 王绍武2, 朱锦红2   

  1. 1. 北京师范大学资源科学研究所环境演变与自然灾害教育部重点实验室,北京100875;
    2. 北京大学地球物理系,北京100871
  • 收稿日期:2000-04-25 修回日期:2000-06-20 出版日期:2000-09-15 发布日期:2000-09-15
  • 基金资助:
    国家重点基础研究发展规划项目(G1998040900);国家自然科学基金资助项目(49635190)

Surplus Summer Rainfall Along the Middle to Lower Reaches of Changjiang River in the 1990s

GONG Dao yi1, WANG Shao wu2, ZHU Jin hong2   

  1. 1. Laboratory for Environmental Change and Natural Disaster Research, Institute of Resources Science, Beijing Normal University, Beijing 100875, China;
    2. Department of Geophysics, Peking University, Beij ing 100871, China
  • Received:2000-04-25 Revised:2000-06-20 Online:2000-09-15 Published:2000-09-15
  • Supported by:
    National Key Developing Program for Basic Sciences,No.G1998040900;National Natural Science Foundation of China,No.49635190

摘要: 对长江中下游地区32个测站1951以来的降水记录以及上海、南京等6个站120年降水序列的分析表明,1990年代是长江中下游地区近百年来降水最多的10年。降水的偏多导致洪涝发生的频率及强度都加强。最近120年中12次异常多雨的年份,出现在1990年代的就有4次。1951年以来的6个异常多雨夏季个例的合成分析表明,与洪涝直接相联系的大气环流形式是在江南有偏强的向北经向风及水汽输送异常,而在华北及偏北地区有异常的向南经向风异常,在长江中下游地区的辐合造成降水的异常偏多。1990年代北方地区偏强的向南经向风异常可能是造成长江中下游地区降水偏多的主要原因。模式模拟及历史气候变化的事实都说明在气候偏暖的时候,长江中下游地区容易出现过量降水形成洪涝。

关键词: 夏季降水, 长江中下游, 大气环流, 全球变暖

Abstract: There were a series of severe floods along the middle to lower valley of Changjiang River of China during the 1990s. The extensive summer (June, July and August) precipitation is mostly responsible for the flooding. The summer rainfall in the 1980s and the 1990s is much higher than that in the prior 3 decades. The means for 1990~1999 is +87 62 mm above normal, marked the 1990s the wettest decade since 1951. Six stations are selected to establish century long rainfall series. These two series correlate at 0 92 for the period 1951~1999. It is found that the 1990s is also the wettest decade during the last 120 years. Four of the all 12 abnormal wet years, in which more than +40% of the rainfall over the normal, has occurred in the 1990s. Composite analysis for the six samples since 1951 presented that the atmospheric circulation anomalies associated with the surplus rainfall along the middle to lower valley of Changjiang River show positive southern wind velocity and moisture flux anomalies in southern China and negative values in northern China in the lower troposphere. There are strong northern winds during the 1990s over the northern China, which may be responsible for the simultaneous summer rainfall along the Changjiang River valley. Although there are some uncertainties in the climate models, it is strongly suggested that the summer rainfall would increase under the global warming as the IPCC modeling results demonstrated. Frequencies of summer rainfall types during the Medieval Warm Period and the Little Ice Age were compared to the normal (AD950 to 1999). Contrast of greater frequency of types 2 and 1b in MWP and of types 4 and 3 in LIA is exciting. It proves again the statement that warm/dry (or cold/wet) climate was predominated in north and warm/wet (or cold/dry) climate in southeast China.

Key words: summer rainfall, Changjiang River, atmospheric circulation, global warming

中图分类号: 

  • P46