ABSTRACT:
One of the models for estimating erosion rates with the greatest acceptance and widest application is the Universal Soil Loss Equation. In this model, the erosive power of the precipitation is considered by an erosivity factor. In this work, an analysis of rainfall erosivity in four locations (Cordoba, Sevilla, Huelva, and Cadiz) of western Andalusia (southern Spain) is shown. The EI30 and EI60 rainfall erosivity indices were obtained by taking 10-minute resolution data series of rainfall and then correlating them. The relation obtained was then applied to longer hourly precipitation data series, in order to calculate and fit the accumulated erosivity curves for different probabilities at each place. The differences that appeared when separating the rainfall events by one or by six continuous dry hours were studied. The erosivity values obtained were approximately 25% to 30% higher when using six hours of separation. A clear difference in the distribution of erosivity throughout the year was detected between the coastal and the inland locations. Also, the relations for calculating rainfall erosivity with daily precipitation were obtained. Finally, the exponential expression of the kinetic energy fitted for the south of Portugal was verified for Huelva, and it was observed that erosivity results exceeded by approximately 16% to 19% those obtained by applying the Universal Soil Loss Equation. However, the global behavior of erosivity was similar, making both methods equally applicable in the study region.
Footnotes
Luis Dominguez-Romero has a PhD fellowship and Jose Luis Ayuso Muñoz and Amanda P. Garcia Marin are professors in the Department of Rural Engineering at the University of Cordoba in Spain.
- Copyright 2007 by the Soil and Water Conservation Society
This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.