Avaliação de modelos digitais de elevação como alternativa para estudos hidrológicos em pequenas bacias.

Abstract

The development of methodologies related to the river has been the subject of many studies on water resources. In the case of the topography, the spatial resolutions presented by orbital products are usually incompatible with the dimensions of the basin and the lack of sufficient topographic data to represent it properly can make it difficult to use some hydrological models. A digital elevation model (DEM) and assists in representing the earth's surface can be used as input parameter in hydrological models. However MDE can result in completely different representations of the same area. The use of MDE (Satellite images obtained by active sensors (radar), optical images from orbital or aircraft (aerial photography), by different interpolation algorithms and so on.) In hydrological studies need to be careful. The objective is to test different possible interpolation for surveying existing guidelines and establish comparisons and selection, examine the applicability of radar imagery (ASTER and SRTM) in small basins of semiarid and generate DEM as input to a model hydrosedimentological comparing the different results from different MDE in order to guide other research projects focused on water resources. By generating two different DEM from topographic surveys (conventional and automated) and satellite images supported by geo-specific software was possible to obtain results that characterize the Experimental Basin of Sao Joao do Cariri (EBSJC) on aspects of drainage, boundaries, relief and geomorphology. The results point to the need of data surrounding the basin for a more reliable characterization, as well as the possibility of using a particular "hybrid" with input samples that come in different forms of acquisition (images, field surveys, etc.). We also emphasize that for small basins, the products available orbital still have unsatisfactory results for most of the analysis performed. Finally, the paper presents some comparisons of different results obtained in order to support the choice of an DEM in similar situations.