Taiwan is a mountainous island with frail geology. It often has severe soil erosion during the rainy season. In order to reasonably estimate the amount of soil erosion with equations such as USLE, RUSLE and TUSLE, it is necessary to investigate the regional variations of the rainfall erosion index (R). In this study, ten climate
regions were identified, and their raw rainfall recording sheets, and hourly and daily rainfall records were analyzed between 1975 and 2014. The results indicate that the maximum 30-min rainfall intensity (I30) and the maximum 60-min rainfall intensity (I60) are highly correlated in effective rainfall events. Also, we found significant regional and monsoon and typhoon route effects. The ratio of I30/I60 ranged from 1.22 to 1.55. Moreover, the variations of rainfall characteristics caused by global warming were investigated. The relationships between annual rainfall and rainfall
erosion index for 10 representative stations were derived for recent years (2001-2014), and applied to 339 precipitation recording stations. Accordingly, the Taiwan annual rainfall erosivity map was revised. The revised map can be used for soil and water conservation planning.
Key Words : Effective rainfall amount, Rainfall erosion index, Maximum 30-min rainfall intensity (I30), Maximum
60-min rainfall intensity (I60), Rainfall erosivity map.