Hydrology and Earth System Sciences www.hydrol-earth-syst-sci.net 1027-5606 1607-7938 8 1 2004 10.5194/hess-8-103-2004 http://www.hydrol-earth-syst-sci.net/8/103/2004/ http://www.hydrol-earth-syst-sci.net/8/103/2004/hess-8-103-2004.html http://www.hydrol-earth-syst-sci.net/8/103/2004/hess-8-103-2004.pdf 103 107 0000-00-00 Estimating RUSLE’s rainfall factor in the part of Italy with a Mediterranean rainfall regime N. Diodato Monte Pino Naturalistic Observatory, Contrada Monte Pino, 82100 Benevento, Italy E-mail: nazdiod@tin.it The computation of the erosion index (<i>EI</i>), which is basic to the determination of the rainfall-runoff erosivity factor <i>R</i> of the Revised Universal Soil Loss Equation (RUSLE), is tedious and time-consuming and requires a continuous record of rainfall intensity. In this study, a power equation(r² &#61; 0.867) involving annual erosion index (<i>EI</i>_30-annual) in the Mediterranean part of Italy is obtained. Data from 12 raingauge stations are used to derive and then test a regional relationship for estimating the erosion index from only three rainfall parameters. Erosivity rainfall data derived from 5 additional stations are used for validation and critical examination. The empirical procedures give results which compare satisfactorily with relationships calibrated elsewhere.</p> <p style="line-height: 20px;"><b>Keywords: </b>erosion index, rainfall, erosivity, Revised Universal Soil Loss Equation