本文目的在分析氣候變遷對2046-2065年臺灣降雨之影響,文中以排放情境特別報告之A1B溫室氣體排放情境為基準,利用五種大氣環流模式輸出之降雨量,與1980-1999年歷史資料進行年降雨量分析、一至三日暴雨與連續不降雨日數之旱澇分析與比較,以了解台灣在未來降雨變化情況。結果顯示:北部地區未來年降雨量有減少之趨勢,中部變化不明顯,南部與東部則有增加之趨勢。如以豐枯水期降雨比例來看,未來北部與東部地區降雨比例變化不大,但中南部差異則更為明顯。未來全臺暴雨情勢皆較現況減緩,以西北部沿海與中央山脈一帶最為明顯,原來為暴雨中心的阿里山,於未來暴雨量亦有明顯降低。另一方面,未來全臺乾旱情勢將較現況嚴重,其中以東北角、北部、西北部與高屏山區較為明顯,於迴歸期100年情況下,唯有宜蘭花蓮部分地區最大連續不降雨日數仍低於50日。
The purpose of this study is to assess the impact of climate change on rainfall frequency in Taiwan, for droughts and storms. Based on five downscaled General Circulation Models under SRES A1B emissions scenario, frequency of the maximum consecutive dry days and maximum 1-day, 2-day, and 3-day rainfall within 2046-2065 are estimated, as compared with those within 1980-1999.The results show the risk of droughts has a tendency to increase but the risk of storms has a tendency to decrease in Taiwan in 2046-2065, especially western and northern region. The distribution of rainfall in central and southern Taiwan would be more uneven, and the ratio of rainfall of wet to dry season would raise in the future.