CALIBRAZIONE DI MODELLI USLE-DERIVATI MEDIANTE I MASSIMI ANNUALI DELLA PERDITA DI SUOLO PER EVENTO

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Abstract

[automatically translated] Several experimental results have shown that the loss of many years of soil of a field is influenced appreciably by the erosion that occurs in a limited total number of particularly demanding events. Accordingly, an approach to soil conservation calibrated average annual erosion can not be very effective at the most significant weather events from total erosion point of view. The availability of water erosion prediction models plot can provide accurate estimates of the highest values of soil loss to scan single erosive event is therefore of practical interest, being able to help improve the choice and dimensioning of anti-erosion measures in an area of interest. In this survey, conducted with reference to data obtained in the experimental plots Sparacia, in Sicily (length, λ = 11-44 m, the slope, s = 14.9 - 26.0%), it is preliminarily determined that the annual loss of soil is due to a reduced number of events and, in particular, that the maximum annual roughly determine the 75% overall erosion. It then examined the applicability of the USLE and USLE-derived models for the prediction of annual maximum of soil loss per event, calibrating each model in regards to this particular type of events. The analysis highlights the superiority approach USLE-MM than the USLE and USLE-M. With the USLE-MM, soil erodibility factor, assumed constant for the entire experimental area, and the expression of the slope length factor show no significant dependence on the type of data used for calibration (maximum annual, all events). The annual maximum damage instead rise to higher values of the slope factor of the slope with respect to those obtained considering the complex of events. The differences between the values of the aforementioned factor obtained with the two datasets grow with the slope, taking a minimum value of 17% for s = 14.9% and a maximum of 61% for s = 26.0%. This result indicates that the effect of the slope on the soil loss is greater in the case of annual maximum with respect to the totality of events, probably in consequence of the greater efficiency of the transport mechanisms in the case of particularly demanding events.
Original languageItalian
Pages463-473
Number of pages11
Publication statusPublished - 2016

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