Conversão do modelo digital de superfície (MDS) a modelo digital de elevação hidrologicamente condicionado (MDEHC) para a bacia hidrográfica do Córrego do Marinheiro, Sete Lagoas – MG

Abstract

A correct and accurate cartographic representation of the relief of watersheds is increasingly required due to the increased human actions on water resources. The objective of this work was to propose a conversion of the digital surface model (DSM) to the hydrologically conditioned digital elevation model (HCDEM) for the Marinheiro Stream Watershed in Sete Lagoas MG, Brazil, as a subsidy for hydrological and environmental analyses in this region. The methodology was developed in seven stages: a) Automatic classification of the Geoeye image; b) Ordinary kriging of the DSM points for areas without arboreous vegetation; c) Obtaining of the contour lines; d) Obtaining of points of exposed soil areas of the DSM and obtaining of the drainage network; e) Obtaining of the hydrologically conditioned digital elevation model (HCDEM); f) Correcting of the topographic profile of the drainage network region; and g) Analysis of the results. According to the results, the conversion of the model minimized the canopy effects and increased the coherence of the representativeness of the relief surface. The standard deviation found was 3.9 m, confirming the better performance of the HCDEM over the DSM, which presented a value of 4.95 m. Therefore, according to the validation points obtained in the field, the product of this study has a consistent basis for accurate and reliable hydrological, geomorphological, and geo-ecological analyses in the evaluated watershed.