The importance of retrospective geomorphological cartography for the definition of complex morphological units – the Tamanduateí River Basin, Metropolitan Region of São Paulo

Abstract

The article presents the methodological approach adopted for the production of the Map of Complex Morphological Units of the Tamanduateí River basin in the Metropolitan Region of São Paulo. This cartographic product results from the correlation between the Pre-Urban Geomorphology and Anthropogenic Morphologies maps and, therefore, relies on retrospective and evolutionary geomorphological cartography. Retrospective and evolutionary cartography consists of identifying and representing the original morphology (pre-urbanization phase) and the sequence of interventions in surface forms and materials, providing an important tool for identifying and interpreting changes in processes. The recognition of the original morphology was based on the general principles of geomorphological cartography, from the analysis and interpretation of aerial photographs from 1952 and 1962, old topographic and planimetric maps, historiography of the city of São Paulo and its surroundings, and iconographic materials. For the preparation of the Anthropogenic Morphology Map, the Land Use and Occupation Maps of the Metropolitan Region of São Paulo and Alto Tietê Basin (Empresa Paulista de Planejamento Metropolitano do Estado de São Paulo [EMPLASA/SP], 2005) were used, as the legend offers important information reflecting some of the indicators of changes pointed out by Rodrigues (2008) for the evaluation of hydrogeomorphological impacts and changes. From the correlation between six units of Original Morphology and seven units of Anthropogenic Morphologies, a total of 33 Complex Morphological Units were obtained. This synthesis allowed the identification of changes processed over more than 150 years and the identification of the types of original morphology on which they were processed.