O USO DO RECONDICIONAMENTO DE MDE PARA CORREÇÃO DA DISCRETIZAÇÃO DE BACIAS HIDROGRÁFICAS NO MODELO MGB

Abstract

The hydrographic basin is traditionally considered as the spatial unit of study, planning and management of water resources, as it constitutes a system that includes the physical and economic interactions that influence water availability. However, before carrying out a study of the effects of these interactions, it is important that the initial work goes through the delimitation of the basin whose physiographic attributes are inherent. For this, technologies of Geographic Information Systems - GIS are adopted that allow extraction of morphometric characteristics with the insertion of Digital Elevation Models - DEM in hydrological models. However, the presence of dense vegetation in the study areas promotes the generation of false altitudes in the DEM, leading the modeling to false flow segments, thus affecting the basin limitation. Therefore, the main objective of this work is to correct the delimitation of the Rio Verde/SP Basin, from the simulation in the Large Basin Model - MGB. The correction technique consists of subtracting the altitude from the DEM by imposing a vector hydrographic information plane, a process known as stream burning, using the ArcHydro Tools program. As a result, it was observed that the altimetric subtraction of the DEM, with the aid of the agree tool of the ArcHydro program, promoted the reconditioning of the DEM and the advancement of the basin discretization steps in the MGB model, which were impossible to proceed with the original DEM. . Thus, after the DEM reconditioning, it was proved that the MGB model was able to obtain greater accuracy of the hydrographic network, and consequently, the delimitation of the basin.