Estimativa da vulnerabilidade dos solos à erosão hídrica na bacia hidrográfica do Rio Cervo - MG

Abstract

The objective of this paper is to estimate the spatial distribution of the average potential annual soil loss in the Cervo River basin, MG, in order to identify the areas most susceptible to water erosion and support possible changes in the natural resources management. By this way, it was applied the RUSLE model (Revised Universal Soil Loss Equation) implemented in a GIS. The factors used in the model were generated in raster format and combined by algebra of maps. The rainfall erosivity factor (R) was obtained based on a geographical multivariate model developed for the Southeast of Brazil; the coverage and management soil factor (C), was derived from land use map made from RapidEye images of 2015; the soil erodibility factor (K), was obtained by the soil map, and the topographic factor (LS), by the DEM (Digital Model Lifting). The results showed that 40.59% of the basin soils have lost more than 10 t ha-1 yr-1 , with predominance "high" class of vulnerability; and 41% of the total area showed the soil loss exceeding the tolerable rate. By the spatial distribution of sources, it was found that 35.6% of these are located in areas with more than 15 t ha-1 yr-1 of soil loss, this result is due to the exposed soil predominance, grazing and agriculture combined with the Udorthent Neossolo regions. Thus, it needs to implement some practices of land cover management and soil conservation in order to reduce the vulnerability by water erosion in the Cervo River basin.