Avaliação do potencial natural de erosão na bacia hidrográfica do rio formoso através da aplicação da equação universal de perda de solo

Abstract

The present study aimed to evaluate the Natural Potential Erosion (NPE) of Rio Formoso’s watershed soils by applying the Universal Soil Loss Equation. To this end, it was necessary to determine the natural variables composing this equation, namely: erosivity, based on data from precipitation events; erodibility, based on the physical characteristics of the region soils; and topographic factor, which is the ratio of length and steepness of slopes in the basin and the product of these factors results in the PNE of the region. As results, it was found that rainfall erosivity had very high level with an average of 9,900 MJ mm ha-1h-1 year-1, Red Yellow Podzolic soils and Litholics present rates of 0.0758 and 0.0530 t h MJ-1 mm-1, respectively, these numbers are significantly higher than that observed for the other types of soil found in the basin, the topographic factor was computationally obtained and showed values of relatively small averages and performed with smaller values related to sedimentation basin areas and higher values to the drainage channels. Formoso’s NPE in the river basin presented high average, 1.200 t ha-1, being the erosivity factor one of the most influential to achieve such values, the results were spacialized in the form of maps and are of highly valuable for establishing environmental planning policies that consider the susceptibility of soil to erosion.