Resumo

AIMAR, Silvia Beatriz; MENDEZ, Mariano Javier  e  BUSCHIAZZO, Daniel Eduardo. Wind erosion prediction with the EWEQ model in two loess soils: effects of climatic condition. Cienc. suelo [online]. 2011, vol.29, n.2, pp.253-264. ISSN 1850-2067.

The potential wind erosion of a soil (EEP) is a basic data for predicting wind erosion of agricultural soils in most wind erosion prediction models. The objective of this study was to compare the predicted EEP of two soils by means of the Spanish Version of the Wind Erosion Equation (EWEQ), with field-measured EEP in a semiarid environment of Argentina, loaded with different climatic C factors. Wind erosion measurements were carried out along one year in a Typic Ustipsammment and an Entic Haplustoll, both maintained bare and flat along the sampling period. Results indicated that EEP was higher in the Ustipsamment (270 Mg ha^-1 yr^-1) than in the Haplustoll (40 Mg ha^-1 yr^-1). These amounts represented 21,3 and 3,1 mm losses of the topsoil. Wind erosion of the Ustipsamment was twice in Spring-Summer than in Autumn-Winter. This effect was not observed in the Haplustoll, due to a slower drying rate after a rainfall event, which maintained the soil surface moist during a longer period of time. Storm duration explained 40% of the wind erosion variability in both soils. Wind erosion rates (Qt, EEP per unit time) correlated positively with the mean wind speed in both soils. At similar wind speeds, Qt was always higher in the Typic Ustipsamment. The EEP calculated with a C factor corresponding to the sampling period (30,3) was the most similar to field measurements, but EWEQ underestimated wind erosion by 43% for the Haplustoll and by 18% for the Ustipsamment. The EWEQ model should include different climatic C factors in order to offer the user the prediction of wind erosion under variable climatic scenarios.

Palavras-chave : Wind Erosion; Semiarid Regions; Prediction Models.

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