| Summary: | 碩士 === 國立彰化師範大學 === 地理學系 === 104 === In this study, the reanalysis rainfall dataset from TCCIP has been used to exam the changes of long-term rainfall in temporal and spatial patterns during the period of 1970-2012. The results show that five rainfall periods have been identifying, and the major rainy season occurs in Meiyu season (from May to June) and typhoon season (from July to September). The rainfall during these periods accounts for 71% of the total rainfall over a year. The major rainfall area could been divided into five sub-regions in Taiwan and covers almost 40% of the total area, these regions located in north coast area, southern YiLan County, and mountain areas in the north part, central part and south part of western Taiwan. In the north coast area, the main rainfall located between Tatun volcano group and Nangang Range. The rainfall area of YiLan County is located in the north part of Central Mountain Range, namely, Nan-ao Mountain. In the Northern Taiwan, the rain area located in Jialishan Range and the west side of Xue Mountain Range. In the Central Taiwan, most of rainfall located in Heping District, Taichung city, Luchang Mountain and Yinyin Peak. In the Southern Taiwan, Alishan Range, Yushan Range, and the west side of Central Mountain Range are the major regions. The average daily rainfall intensity greater than 5 mm, and these major rainfall areas are associated with terrain elevation, slope, direction, and large-scale wind direction. Most heavy rainfall (≧20mm/day) occurs same as above period and location. The heavy rainfall occurs more frequently since 1998, and rainfall intensity averaged over the entire 99th percentile and the entire 90th percentile also showed an increase since 2000, especially in the Southern Taiwan.
|
|---|
