Delimitação de bacia hidrográfica em região montanhosa a partir de diferentes modelos digitais de elevação

Abstract

ResumoA correta delimitação dos divisores de água da uma bacia hidrográfica é de grande importância para estudos ligados à modelagem hidrológica e ambiental. Tal procedimento é realizado de forma automática em aplicativos computacionais de Sistemas de Informações Geográficas, por meio de algoritmos que identificam os divisores de águas a partir de uma representação matricial da topografia do terreno, denominada Modelo Digital de Elevação (MDE). O presente trabalho avaliou a delimitação automática de uma bacia hidrográfica situada em região montanhosa do Sul do Estado do Espírito Santo (Brasil) feita a partir de seis diferentes MDEs: três MDEs originários de imagem de radar (SRTM) e seus refinamentos, além de três MDEs originários de processos de interpolação espacial de curvas de nível por meio de diferentes formas de interpolação. Verificou-se que o MDE gerado a partir das curvas de nível e da hidrografia mapeada utilizando o interpolador Topo To Raster apresentou o melhor desempenho de representação do relevo da bacia para fins de delimitação da bacia hidrográfica analisada. Palavras-chave: Modelagem hidrológica, sistemas de informação geográfica, interpolação AbstractThe precise delineation of watersheds is essential to studies related to environmental and hydrologic modeling. Such delineation is performed automatically in GIS softwares using algorithms that identify the watershed from grid representation of the terrain, the digital elevation model (DEM). This study evaluated the automatic delineation of a watershed located in the southern mountainous region of Espirito Santo (Brazil) using six different DEMs. Three MDEs were obtained by radar images (SRTM) and its refinements. Other three MDEs were obtained by process spatial interpolation of topographic data using different interpolators. It was found that the MDE obtained by the interpolation of topographic data using Top To Raster interpolator, (taking mapped hydrography as support) promoted the best representation of the watershed topography for the purpose of its delimitation.

Physical parameters of the cachimbal river sub-basin associated to landscape change in Pinheiral-RJ, Brazil

“…The dimensions of a river basin and its morphometric attributes are responsible for its interior dynamics. Cecílio et al (2013) state that the larger the area, the greater amount of time available for the hydrographic channels to contribute jointly to the drainage area, thus reducing the potential for flood susceptibility. Figure 2 shows the altitude measurements of the study area, which vary from 360 to 744 meters.…”

Assessment of digital elevation models to obtain morphometric characteristics in relief transition region

“…The knowledge of morphometric characteristics of watersheds is fundamental in the development of hydrological studies for the purposes of better planning and management of water resources (Aher et al, 2014). These characteristics are important for: the estimation of the runoff depth and time of concentration of the flow in the basin (Silva et al, 2006;Abdulkareem et al, 2018;Mudashiru et al, 2018); the regionalization of flows (Fioreze et al, 2008;Bassiouni et al, 2016); hydrological modeling (Chaplot et al, 2006;Cecílio et al, 2013;Meraj et al, 2015;Abdulkareem et al, 2018); and as indicators of the degree of vulnerability of the basin to phenomena such as floods and soil erodibility (Esper Angillieri, 2008;Gebrehiwot et al, 2011;Ameri et al, 2018).…”

“…The DEMs may be obtained by remote sensing data or generated from the interpolation of point topographical data and contour lines extracted from topographic maps (Oliveira et al, 2010;Cecílio et al, 2013). In Brazil, the most common data source for the generation of the DEMs are the contour lines, and of supplementary form, the hydrography and the elevation points obtained from topographic maps.…”

“…The quality of the DEMs is fundamental to the success of hydrological studies, especially when it comes to modeling (Chaplot et al, 2006), because depending on the characteristics of the DEM (scale, resolution and origin), the automatic delineation of a basin and, consequently, its morphometric characteristics, may differ significantly (Pires et al, 2005;Alcaraz et al, 2009;Seyler et al, 2009;Cecílio et al, 2013). Thus, several studies have been conducted to analyze, compare and update the information on the earth's surface, obtained by means of Rev.…”

“…The authors observed that DEMs derived from the 1: 50,000 topographic map and ASTER V2 data are more accurate and consistent in terms of absolute accuracy than the other DEM data products generated or available, based on the morphometric parameters extracted from each. Cecílio et al (2013), also in mountainous conditions, evaluated the precision of DEMs for the automatic delineation of a river basin. The DEMs evaluated originated from radar images (SRTM) and spatial interpolation of contours (1:50,000 scale), with a spatial resolution of 10 x 10 m. The authors verified that the DEM generated from the contour lines and hydrographic mapped using the interpolator Top To Raster presented the best performance of representation of relief of the basin.…”