USO DE TÉCNICAS DE GEOPROCESSAMENTO PARA MAPEAR O POTENCIAL NATURAL DE EROSÃO DA CHUVA NA BACIA HIDROGRÁFICA DO RESERVATÓRIO DE CACHOEIRA DOURADA – GO/MG

摘要

Natural potential erosion were defined from their main naturalconditioners in the region of hydrographic basin of CachoeiraDourada (between Goiás and Minas Gerais states −Brazil), withgeoprocessing techniques and the Universal Soil LossEquation (USLE). Upon the decision for natural erosionpotential, a matrix with values of erosivity (R), erodibility (K),declivity, and ramp length (LS) was elaborated, where classesof low, medium, high, very high, and extremely high naturalerosion potential (NEP) were established. Spatial distributionfor the factors R, K, LS, and PNE was defined. The highestaverage R index for the rainy series was 8173.50 MJ ha mm-1h-1 year-1. The period with data from 30 years (1973 – 2002)showed that the reservoir basin displayed areas susceptibleto rill and interill erosion (69.16% of the total). There is apredominance of low erosion potential among the classes,which can be explained due to the soil predominant classesas well as to the low declivity. Areas with medium to extremelyhigh erosion potential require the adoption of measures toavoid start and development of more severe erosion processes(ravines and gullies).