Adaptation of RUSLE in the Eastern Part of the Mediterranean Region

Abstract

Empirically based models are used worldwide to estimate soil erosion. The Revised Universal Soil Loss Equation (RUSLE) is one such model that has been intensively tested and validated under conditions in the United States. RUSLE estimates average soil loss as a function of five main factors: rainfall erosivity (R), soil erodibility (K), crop management (C), support practice (P), and topographic (LS) factors. This study investigated the application of RUSLE to Mediterranean conditions. The validation and calibration of RUSLE in the study area utilized field plots' soil erosion measurements. The results found the RUSLE soil loss estimation to be three times the actual soil loss (7.8 and 2.6 Mg/ha, for RUSLE and actual measured soil loss, respectively). The difference between the RUSLE factors and the measured factors were responsible for the differences between the soil loss estimation by RUSLE and the measured soil loss. Specifically, the RUSLE K-factor showed three times the magnitude of the measured K-factor, the RUSLE C-factor underestimated the measured C-factor, and the RUSLE P-factor overestimated the measured P-factor by three times. Adjusting the RUSLE factors according to the measured ones increased the model's predictability, whereas the adjusted-RUSLE soil loss estimation underestimated the measured soil loss by 14%. The adjustment of RUSLE, according to the prevailing conditions of the study area, increased the model efficiency three times (0.26 and 0.86 before and after adjustment of the mode, respectively). For more accurate and reliable validation of the RUSLE under the Mediterranean conditions, it is advisable to conduct long-term soil loss experimentation and measurements.

Geomorphic mapping in endorheic catchments in the Spanish Pyrenees: An integrated GIS analysis of karstic features

“…However, in mountains of Palestine, Hammad et al (2004) estimated a mean value for the topographic factor of 0.36, which is lower than the mean value for the Estaña catchment.…”

Soil erosion risk scenarios in the Mediterranean environment using RUSLE and GIS: An application model for Calabria (southern Italy)

“…Moreover, the RUSLE model produces overpredictions of low WSE values and underpredictions of high WSE values (Risse et al, 1993;Rapp et al, 2001;Shrestha et al, 2004;Kinnel, 2005). For example, assessments of WSE obtained in the Mediterranean climate applying the RUSLE model may overestimate even three times those observed (Abu Hammad et al, 2005). Ultimately, models such as USLE and RUSLE, originally developed for a detailed scale application in the farming sectors, if applied to a regional scales in different environments must take into account some limits: the obtained values of soil erosion must be employed for comparative purposes and not considered in absolute terms (Šúri et al, 2002).…”

Predicting plot soil loss by empirical and process-oriented approaches. A review

“…At present, the USLE is very widely applied in Europe and in many other Mediterranean countries and no scientific evidence exists that RUSLE (Renard et al, 1997) or RUSLE2 without adaption is better than the USLE in European and Mediterranean environments (Abu Hammad et al, 2005). In any case, the RUSLE equation conserves the same mathematical structure of the USLE, the revision being limited to improved estimation of some factors.…”