Effects of anthropic transformations on the margins of Una River, Taubaté, São Paulo, Brazil

Abstract

This study sought to support the mapping of occupied areas on the margin of rivers through the use of geoprocessing imaging technologies combined with the application of indices that measure the effects of the anthropic transformations in the environment, in order to verify the environmental degradation. The Anthropic Transformation Index is demonstrably efficient for space-time analyses on river basins and at environmental protection areas. In order to develop a data base to support public policies related to the preservation of the Una River Basin, this article presents the effects of the anthropic actions in the years 1962 to 2014, in the registry district of Taubaté, in the Vale do Paraíba Metropolitan Region. In order to collect data using photos and aerial images of the territory, geo-referencing and vectorization were performed by the QGIS program, which enabled quantification of the occupation and land use. Five occupational categories types had been identified in the area: watercourses, riparian forest, field or pasture, denser forest and urbanization. Afterwards, the ITA was applied and the index 5.5 was obtained, which indicates a degraded area, based on the percentage of land use and occupation. It was concluded that the greatest change occurred in a 52-year time span, in the landscape of registry district, where a marked anthropic pressure was observed.it is the significant anthropic pressure, close to the watercourses, towards the Una River Basin, in the city of Taubaté, in the state of São Paulo.