MEASURING FIELD RILL ERODIBILITY BY A SIMPLIFIED METHOD

Many process-oriented erosion prediction models reproduce rill erosion as affected by site-specific parameters, as for example, rill erodibility,and thus, their practical application requires the measurement of these parameters or their estimate.The aim of this paper was establishing a method for indirectly measuring field rill erodibility. A simple mathematical approachbased on a known soil detachment equation and accounting for the rill erosion dynamic process is applied. Field measurementscarried out for seven natural rainfall events occurring at the plots of the Sparacia experimental station, southern Italy, are used forindirectly measuring the rill erodibility of the investigated soil. This method needs only the knowledge of the geometric characteristicsof the rills at the end of the erosion event and the event duration. The method was also tested by using the Water ErosionPrediction Project database, and this analysis showed that a reliable value of rill erodibility can be obtained by the proposed Equation18. The proposed method has the following advantages: (i) to be applicable at field scale, being more realistic than the laboratoryscale because the soil structure is not destroyed, and (ii) to avoid the disadvantages of field experiments such as the cumbersomeexperimental set-up and the large volume of water inflow needed