SOIL SUSCEPTIBILITY TO EROSION IN TARUMÃ-AÇU RIVER HYDROGRAPHIC BASIN (AMAZONAS – BRAZIL)

Abstract

Located in the city of Manaus, Tarumã-Açu Hydrographic Basin (TAHB) has been facing profound changes regarding its land use and coverage in the past years, which can be observed in areas affected by urban expansion. Thus, this paper aims to identify the levels of susceptibility of TAHB to soil erosion through geoprocessing techniques, variables of land use, declivity, soil types and geology. For that, images from Landsat-8 OLI satellite were used, as well as the digital SRTM elevation model. In addition, pedology and geology vector data were used to create thematic maps. Based on these data, the basin soil susceptibility to erosion was evaluated, tracing the correlation between variables, which was made possible through the Spring Spatial Language for Algebraic Geoprocessing and the Analytical Hierarchy Process (AHP) method. The results show predominance of wavy terrain (43.34%) and yellow oxisols (97.4%) covered by forests, with low to moderate levels of soil erosion susceptibility. Considering the basin´s drainage, it is noted the occurrence of areas with higher levels of susceptibility in the lower sector of the basin, while in the basin’s upper sector the levels of susceptibility   are lower.