Detailed morphological mapping as a tool for assessing environmental degradation in river basins: a case study of the Jacareí River Sub-basin (São Paulo, Southeast Brazil)

Abstract

Studies addressing environmental issues have become increasingly urgent. The present article proposes to investigate the anthropogenic impacts on the drainage network and the physical environment of a hydrographic sub-basin of the Jacareí River, which is part of the Cantareira System, essential for the water supply of the Metropolitan Region of São Paulo. The objective of this study is to demonstrate the potential of producing detailed morphological maps, in combination with land use maps, to support the assessment of environmental degradation and the development of mitigation and recovery strategies. The methodology was based on a bibliographic review, aerial photointerpretation and morphological mapping techniques, fieldwork and comparative analysis of documents. An anthropogeomorphological approach was adopted to evaluate human interventions in environmental processes, such as deforestation, urbanization and tourist infrastructure. The results indicate that human occupation has significantly altered the relief and water flow of the sub-basin, intensifying the risks of environmental degradation. The mapping revealed the slope sectorization and patterns of human intervention that may compromise water quality and availability. The cartographic analysis highlights the need for integrated environmental planning to ensure the preservation of the river basin and the regional water supply.