Atualização cartográfica por produtos sensores gratuitos na bacia hidrográfica do rio Itacaiúnas - Serra dos Carajás

Abstract

The Pará state, is a scenario of major modifications that quickly alter the landscape, mainly caused by mining, farming and more recently, industry. Thus, the evaluation of local cartographic databases is necessary, where available resources, problems and solutions achieved could be represented on maps. The hydrographic basin of the Itacaiúnas river is placed in this context, for embraces the world's largest mineral province, that attract direct or indirectly various projects of economic interest installed in cities such as Marabá and Parauapebas, southeast Pará. This paper updated the cartographic bases in a scale of 1:100,000, using the geographic information system (GIS) as a tool to handle a range of topography and drainage information, extracted from digital elevation model (DEM) acquired and available from radar images data SRTM (Shuttle Radar Topographic Mission). Together with the data obtained by images CBRES-HRC, LIS-P6-III and Landsat-7 ETM, which are all freely available information, allowing the creation of a mosaic of fifty image-letters that illustrate the changes occurred and can be used for any type of work geological, environmental, logistical, and others. The study results showed that drainage network generated by the method of automatic extracting from MDE is very effective for analysis on a regional scale, because it solved the problem of outdated and the lack of information in certain areas. However, for this data can be validated, it’s too important the editing to reduce the amount of noise and improve visualization. A comparison of SRTM drainage network, with the drainage of the IBGE / DSG, allowed observe that there is much similarity in relation to major rivers, however, automatically extracted drainage showed a significant difference between the thalwegs and channels distribution and concentration of probable water courses passage, beyond allows the definition of the order of channels in a more homogeneous and precise. Image-letters contains information that can be manipulated by printed or digital means, allowing constant updating and reduced costs for any work, especially in areas of difficult access like the Amazon.