Sistemas de informações geográficas na espacialização do potencial natural de erosão da chuva na bacia hidrográfica do reservatório de Cachoeira Dourada – GO/MG.

Abstract

Natural erosion potential areas were defined from their main natural conditioners in the hydrographic basin of Cachoeira Dourada, with geoprocessing techniques. Upon the decision for natural erosion potential, a matrix with values of erosivity (R), erodibility (K), declivity, and ramp length (LS) was elaborated, where classes of low, medium, high, very high, and extremely high natural erosion potential were delimitated, obtained spatial distribution for the factors K, LS, and PNE. The highest average R index for the history series was 8173.50 MJ ha mm-1 h-1 year-1. The period with data from 30 years (1973 – 2002) showed that the reservoir basin displayed areas with high susceptibility to laminar and groove erosion (69.16% of the total). There is a predominance of low erosion potential among the classes, which can be explained due to the type of soil predominant as well as to low declivity. Areas with medium to extremely high erosion potential require the adoption of measures to avoid start and development of more severe erosion processes (ravines and gullies).