Soil Detachment Efficiency Coefficient Functions for an Unpaved Road in Southern Brazil

Soil detachment is a key parameter to describe the hydrosedimentological cycle in rural and urban watersheds. Few studies explore the applicability of equations for calculating soil detachment efficiency, especially in specific environments such as unpaved roads in Pinus taeda L. reforestation areas. The aim of this study was to compare the methodologies for estimation of soil detachment efficiency coefficient, available in the openLISEM hydrological model (Rauws and Govers 1988; Morgan et al. 1998; and Morgan 2001), for a section of an unpaved rural road in a Pinus taeda forest in Southern Brazil, over six contrasting rainfall events monitored in 2013. The results of the simulations were compared with monitored series of discharge and sediment production. The Morgan et al. (1998) function resulted in the lowest soil detachment rate, while the Rauws and Govers (1988) function presented better adjusted accumulated values, which are highly affected by the site properties and initial calibration. These results can help in calculating the coefficient of soil detachment by runoff in regions with similar climates.