1957-1996台风对中国降水的影响

摘要

台风活动是中国气候的重要特点之一,它能带来大量降水并造成严重的财产损失.在些地区,台风降水甚至可以在总降水量中占很大比例.本文目的是研究那些对中国产生影响的台风并重点关注台风对中国降水的影响.文中涉及四个方面的工作.首先,研究了影响中国台风的频率,结果表明台风影响的主要季节为5-11月,尤其以7-9月频繁;在过去40年中影响台风的频率没有明显的变化趋势.第二,对台站台风降水的气候特征分析结果显示,海南和东南沿海地区受台风的影响最大,而且长江以南大部地区每年都受到台风的影响;另外,影响区域大部分地区的台风降水在过去40年中表现出下降的趋势,但是只有东北地区南部这种趋势是显著的.第三,对台风个例的分析表明,个例降水总量和影响面积之间存在着显著的线性关系.最后,对台风造成的中国范围降水总量进行了分析,初步结果显示台风降水总量在1957-1996年间显著减少.%Tropical Cyclone (TC) activity is an important feature of China's climate that can have important im-pacts on precipitation and can cause extensive property damage. In particular, precipitation from TCs con-tributes a significant portion of overall precipitation. This study deals with typhoons that influence Chinaand focuses on their impact on China's precipitation. Four aspects are examined in this research. Firstly, thestudy of influencing typhoon frequency reveals that the main season that typhoons affect China is from Mayto November, especially between July and September. The frequency of influencing typhoons was steadyduring the past 40 years. Secondly, inspection of the climatology of station typhoon precipitation shows thatHainan and the southeastern coastalmost regions are most frequently affected by typhoons, and most of theregions south of the Yangtze River are affected by typhoons each year. Meanwhile, during 1957-1996, mostof the typhoon-influenced regions show decreasing trends in typhoon precipitation but only the trends insouthern Northeast China are significant. Thirdly, examination of the typhoon cases shows that there existsa significant linear relationship between the precipitation volume and impacted area. Finally, study of varia-tions of typhoon impacts on China's precipitation suggests that there exists a decreasing trend in the contri-bution of typhoon precipitation to overall precipitation, while total annual volume of typhoon precipitationdecreases significantly during the period.