Typhoon Impacts on China's Precipitation during 1957-1996

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.