Rainfall and runoff erosivity in the alpine climate of north Slovenia: a comparison of different estimation methods

Abstract Rainfall and runoff erosivity is often assessed by using the R factor. For its computation different methods may be used. The aim of this study was to compare some estimation methods for the alpine climate in the Slovenian Alps. Monthly and annual R factor values were calculated according to the RUSLE, using daily precipitation data for the period 1990–2002 in Solčava, which is typical of the alpine region in Slovenia. In this alpine area with rather low rainfall intensities, the expression for computing the rainfall kinetic energy proposed by van Dijk et al. yielded on average 17.9% higher rainfall erosivities than the RUSLE approach. The newly proposed A index yielded on average 40% lower rainfall erosivities than the RUSLE approach. These lower values of rainfall erosivity were caused by the structure of rainfall during erosive events in the alpine region. The analysis in the alpine climate in Slovenia does not support the use of the proposed A index as a replacement for the usually used R factor when assessing rainfall erosivity.

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