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Rainfall Erosivity - Its Distribution and Relationsphi with Soil Loss at Campinas, Brazil

出版	Purdue University, 1977
URL	http://books.google.com.hk/books?id=29-YXwAACAAJ&hl=&source=gbs_api

註釋The rainfall erosion potential for individual storms was calculated for Campinas, Sao Paulo State, Brazil. The erosion potential of a rainstorm is the product of the rainfall energy and the maximum 30-minutes intensity of the storm. Over a 22 year period the average annual erosion indez computed by adding the EI values of storms greater tha 10 millimeter was 690 (values range from 351 to 1410). Monthly and seasonal distributions of the erosion index were established. The data showed that 62% of the annual erosion potential occurs during the months of December to February. The frequency distribution of the total annual and maximum annual individual storm erosion index was skewed, but the logatithms of the data appeared to be normally distributed. Expected average monthly and annual values of erosion potential may be readily estimated from local rainfall amount records by the equation EI = 6.987 (p2/P)0.850. A high correlation was found between actual and estimated EI values. The estimates of average erosion losses over an extended period index values are sufficiently accurate to serve as a sound basis for conservation planning.