Análise das modifica??es ambientais decorrentes da ocupa??o urbana em Rio Grande, RS, entre 1947 e 2014, por meio de um Sistema de Informa??es Geográficas

摘要

This study aims to map and describe the environmental modifications occurred in the coastal city of Rio Grande, RS, between 1947 and 2014, resulting from the urbanization process whereby the municipality passed during the analyzed period. The analysis of these changes provides important information to help making decisions regarding the planning and sustainable use of the present ecosystems. The installation of the maritime port in Rio Grande, RS, was the main factor for urban development and parallel changes in the environment. The analysis focused on the most densely urbanized areas of the city, where currently are the most populous neighborhoods that arose in areas adjacent to the center core, and therefore, with more habitats suppressed over the years. To make the comparative analysis possible, an aerial photography mosaic from 1947 was created, the oldest existing for this region, and other with satellite images from 2014, obtained from Google Earth Pro software. The images passed through the georeferencing process and manual vectorization, and, after the rasterization of vector files generated in the mapping, were analyzed and classified in a GIS. The results showed a large expansion of constructed areas in detriment of the suppressed environments of dunes, sandy fields and grasslands. It is expected that this study supports the environmental management activities of the city, directing the growth from now on, so as to avoid the problems from a chaotic development.