Obtenção de variáveis morfológicas em sig a partir de dados SRTM.

Abstract

The traditional process for generation of digital elevation models, through the digitalization of topographical letters demands larger man power and time, in way that the use of digital bases represents an alternative of great interest. The objective of the work was to develop a methodology for the use of orbital data from the SRTM on generation of digital elevation models hydrologically consistent, making possible the extraction of physical variables on watersheds in GIS. In order to correct imperfections of SRTM data, spurious depressions had been eliminated, a gutter under the hydrographic net was created, edges had been refined and the displacement between the numerical hydrography and the one mapped by IBGE was corrected. Automatic operations in GIS were used to get morphometric characteristics related to to each pixel of the hydrographic net of Rio Doce’s watershed. Were determined: draining area, length of the main river, total length of the draining net and draining density. The results had disclosed exactness in comparable levels to the manual methods, indicating viability in the extraction of morphological characteristics in the Rio Doce’s watershed.