HYDROGRAPHIC AND HYPSOMETRIC DENSIFICATION IN HYDROGRAPHIC BASIN MAPPING: A METHODOLOGICAL ESSAY FOR THE "VALE DO MATAPI", IN THE STATE OF AMAPA, BRAZIL

This paper presents an essay on requalification of topographic charts produced by IBGE in 1995, here called BCR1, to generate a modeling of the cartographic base of reference, called BCR2, with the objective of densifying planimetric and altimetric elements. This type of reclassified product is essential to provide more consistent analysis and thematic procedures for landscape systems, water conservation and tourism potential, such as the Matapi river basin in the state of Amapa (Brazil), which has a close association between these three systems. The work was based on conventional methodological procedures, such as geodetic-topographic survey, photointerpretation and photoreambulation, supported also by computational and alternative methods, such as photogrammetric restitution. The results indicate a significant gain of information about the hydrographic and hypsometric densification of the basin's mapping, with approximately 1,600 primary and secondary channels on land, and 200 primary channels in the flooded areas. The hypsometric gain through this set of cartographic conducts was the addition of six approximate intermediate curves and dozens of dimensions distributed throughout the (hydro) geomorphological unit.