Applying the USLE Family of Models at the Sparacia (South Italy) Experimental Site

Abstract

Soil erosion is a key process to understand the land degradation, and modelling of soil erosion will help to understand the process and to foresee its impacts. The applicability of the Universal Soil Loss Equation (USLE) at event scale is affected by the fact that USLE rainfall erosivity factor does not take into account runoff explicitly. USLE‐M and USLE‐MM, including the effect of runoff in the event rainfall–runoff erosivity factor, are characterized by a better capacity to predict event soil loss. The specific objectives of this paper were (i) to determine the suitable parameterization of USLE, USLE‐M and USLE‐MM by using the dataseries of Sparacia experimental site and (ii) to evaluate their performances at both event and annual scale. The measurements allowed to establish the relationships for calculating the factors of USLE, USLE‐M and USLE‐MM usable at the Sparacia experimental area. At first, for slope‐length values greater than 33 m, the calibration of USLE model at event scale pointed out that sediment delivery processes, that is processes involving deposition of the transported eroded soil particles, occur. The analysis showed that USLE and USLE‐M tend to overestimate low event soil losses, while for USLE‐MM, this tendency is less pronounced. However, the USLE‐MM performed better than USLE and USLE‐M and was able to reproduce better than other two models the highest soil loss values that are the most interesting from a practical point of view. The results obtained at annual scale were generally consistent with those obtained at event scale. Copyright © 2016 John Wiley & Sons, Ltd.

Comparing theoretically supported rainfall‐runoff erosivity factors at the Sparacia (South Italy) experimental site

“…For the 22‐m‐long plots, K MB S MB values calculated by Equation with b 1 = 1.45 were plotted against the steepness s and the following relationship was fitted to the data (Bagarello, Ferro, & Pampalone, , ; Di Stefano et al, ; Figure ): …”

“…As expected, among the three theoretically comparable USLE‐type models, USLE performed worst (Table and Figure ). The comparison between USLE‐M investigated by Di Stefano et al () and USLE‐MB showed that the two models have generally similar statistically performances even if the USLE‐MB yielded a maximum discrepancy factor between predicted and measured soil loss values (176) that was much lower than that of USLE‐M (291).…”

“…A comparison was established among USLE‐MB, USLE, and USLE‐M calibrated for bare plots at the Sparacia site. In particular, this comparison was carried out taking into account that the estimate performance of USLE and USLE‐M was formerly tested by Di Stefano et al ().…”

“…Comparison between measured and predicted soil loss values for (a) USLE (Di Stefano et al, ), (b) USLE‐M (Di Stefano et al, ), and (c) USLE‐MB (Equation ). USLE = Universal Soil Loss Equation; USLE‐M = Modified USLE…”

Modeling and Upscaling Plot-Scale Soil Erosion under Mediterranean Climate Variability

“…Soil losses were quantified in various Mediterranean landscapes by using erosion plots [26][27][28][29][30][31]. The results of these studies have provided important reference outcomes that have had a fruitful repercussion in a range of related disciplines, such as ecology, geomorphology, and hydrology [32,33]. However, monitoring of soil erosion phenomena is often restricted to a few years of observations only, implying that the measurements are not necessarily representative of middle-term fluctuations occurring in ecosystems, especially under a Mediterranean climate [34,35].…”