台灣位於東亞季風區，每年由東亞季風和颱風所帶來的降雨距平相當大；而降雨又是台灣地區主要的用水來源。因此本研究分析1996-2008年台灣每年降雨量的分布以及變化趨勢，希望能進一步了解台灣降雨的時空分布情形，與颱風和東亞季風對台灣降雨的影響、貢獻以及其相關性。 本研究使用克利金客觀分析法，將中央氣象局的局屬綜觀氣象測站及自動氣象、雨量站的雨量資料分析成網格雨量資料。再統計這13年間，年雨量及季節雨量的變化情形與趨勢，並計算年雨量與侵台颱風個數的相關係數。最後再針對台灣的最大年雨量事件做分析。 在本研究中，由降雨的距平可明顯看出2002及2003年為乾旱年；而1996~2008年的年雨量變化趨勢顯示，台灣東部的變化趨勢為負值，而西部及山區為正值。另外由四季的降雨來看，以夏、秋兩季佔年雨量的比例較大，尤其是南部地區的夏季降雨佔了年雨量的60%以上。年雨量與每年登陸台灣的颱風個數相關係數為0.695；由此可知颱風降雨確實是台灣的重要降雨來源之一。分析台灣東北角的最大年雨量事件發現，大坪測站的平均年雨量為6226.8mm，其主要降雨季節為受到東北季風影響的秋季及冬季。且在1998年及2000年，大坪測站的年雨量皆高達8000mm以上；而2000年的降雨則是受到東北季風及2000年象神颱風的影響。 Taiwan is located in the subtropics off the southeastern coast of China. Its climate is strongly affected by the East Asian monsoons. The rainfall, brings by the East Asian monsoon and the typhoon is very important for water resource management in Taiwan. This study analyzes Taiwan’s annual rainfall distribution and the trends during 1996-2008. In doing so,we intend to get a better understandiy on the impact of rainfall over Taiwan from the typhoon and the East Asian monsoon. This study uses the Krigging objective analysis method. The hourly rainfall data were taken form the conventional surface stations around Taiwan and from high-spatial-resolution Automatic Rainfall and Meteorological Telemetry System (ARMTS) stations of Central Weather Burean. This work calculatgs the trend of annual precipitation and the season rainfall and the correlation coefficient between the annual rainfall and the typhoon. Finally, some extreme rainfall events are shown, for the period 1996-2008. Our results show that 2002 and 2003 are distinctive drought years. During 1996~2008 the annual rainfall trends over the eastern Taiwan trend is negative, white the western and mountainous areas are positive. For the seasonal rainfall, the summer and autumn account for 60% of annual rainfall. In particular, the summer rainfall over the southera Taiwan is above 60%. The correlation coefficient of typhoon and annual rainfall is 0.695. In 1998 and 2000, the Daping station shows annual rainfall reached as high as above 8000mm. This high rainfall is consistent with the northerly monsoon and typhoon.
