Estimating Single Storm Erosion Index

Abstract

The computation of the single-storm erosion index, EI, which is the basis to determine the rainfall factor R of the Universal Soil Loss Equation (USLE), is tedious and time-consuming and requires a continuous record of rainfall intensity. In this article, simplified methods for estimating the single-storm EI in the Mediterranean area are developed. In particular, data from 32 Sicilian locations and 3 additional locations in continental south Italy are at first used to derive and test a regionalized relationship for estimating the EI index from only storm amount data. A potential relationship with an exponent equal to 1.54 is obtained. Regionalized relationships for estimating the kinetic energy and EI for an event as a function of rainstorm amount and maximum 30-min intensity are also developed and tested. Since in the Mediterranean area an erosive event may generally last several days, a rule of grouping daily rainfall data in order to reproduce the amount of each erosive event is finally developed and tested.