Raindrop Distributions and Erosivity in Central and Northern Areas of Taiwan and United states

• Main Authors: Wu, S. C., 吳上智
• Other Authors: Lan Jenn-Wu
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/44780697356094832573

碩士 === 國立中興大學 === 土木工程學系 === 85 === Astract The rainfall and runoff factor(R-factor) of the Universal Soil Loss Equation (USLE) varies with areas. The main purposes of this study were to modify the R-factor and the equation of kinetic energy. The R values were calculated based on the raindrop data measured with the stain method for the areas of Yang-Ming Mountain in Taipei, Taipei City, Taichung City and Lien-Hua Chi in Nan-Tou. The results showed that the rainfall kinetic energy curve of Yang-Ming Mountain in Taipei, Taichung City and Lien-Hua Chi in Nan-Tou were fairly close to that of Washington D.C.,USA ,while the rainfall kinetic energy curve of Taipei City was lower than that of other three experimental areas. The foreign raindrop size data measured with photographic method by Mueller are also analyzed in this study. The results indicated that based on Muller''s data the rainfall kinetic energy curve for most areas were lower than that of Washington D.C.,USA. The mean annual R values were estimated using the rainfall kinetic energy formula of Yang-Ming Mountain in Taipei,Taipei Ciy,Taichung City and Lien-Hua Chi in Nan-Tou, and the rainfall records of the four areas. The mean annual R values were 1210 ,530 ,563 and 596(100.ft- tons.in.ac.hr.yr) for Yang-Ming Mountain in Taipei, Taipei City,Taichung City and Lien-Hua Chi,respectively. To probe into the difference in raindrop size distribution between domestic and foreign data, the goodness of fit of data to different probability distributions were studied. Based on the Kolmogorov-Smirnov test,it was found that the beta distribution gave the highest passage ratio for the domesitc data. The foreign data were analyzed with a Kolmogorov-Smirnov test.The results showed that among the four probability distributions considered the beta distribution and the log-normal distributions gave description on the raindrop size distribution.