Estimativa da vulnerabilidade dos solos à erosão hídrica na bacia hidrográfica do Rio das Mortes (MG)

Water erosion is one of the major causes of soil degradation, causing soil losses higher than natural replacement rates. The spatial distribution of the average annual land loss in the Rio das Mortes MG Brazil, hydrographic basin is estimated, whilst the most susceptible areas to water erosion are identified to manage the region´s natural resources. The Revised Universal Soil Loss Equation (RUSLE) model within the SIG environment was applied. Rain erosion factor, based on a multivariate geographic model developed for Brazil, was obtained; soil coverage and management factor were retrieved from the Brazil soil usage map; the soil erosion factor was obtained by the soil map of Minas Gerais; the topographic factor was determined by the digital elevation model. Maps of factors were determined by map algebra which produced the map of soil vulnerability to water erosion. Further, 45.20% of soils of the hydrographic basin under analysis featured ‘slight’ vulnerability to water erosion. However, 50.28% of the basin area showed a loss of soil which was greater than 10 t ha-1 year-1. The above revealed areas highly susceptible to water erosion and evidenced the need for implementation of improvements in soil management and conservation practices.