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在威许迈耳—史密斯(Wischmeier Smith)通用土壤流失方程中,降雨侵蚀指数是重要的参数之一。降雨侵蚀指数的概念为降雨动能与30分钟最大暴雨强度的乘积,即EI_(30)。其计算值的精确与否对土壤流失量的估算结果有很大影响。 由于世界各地降雨类型不同,所以不少地区都制定了计算侵蚀指数的经验公式。苏联一般采用的计算公式为: EI_(30)=0.258pI_(30)-0.149(1) 式中 P—降雨深,mm:I_(30)—30分钟最大降雨强度,mm/min。
In the Wischmeier Smith general purpose soil loss equation, the rainfall erosivity index is one of the important parameters. The concept of rainfall erosion index is the product of the kinetic energy of rainfall and the maximum storm intensity of 30 minutes, EI_ (30). The accuracy of the calculated values has a great impact on the estimation of soil loss. Due to the different types of rainfall around the world, many regions have formulated empirical formulas for calculating erosion index. The formula commonly used in the Soviet Union is as follows: EI_ (30) = 0.258pI_ (30) -0.149 (1) where P-rainfall depth, mm: I_ (30) -30 minutes maximum rainfall intensity in mm / min.