Dinâmica espaço-temporal da paisagem da bacia hidrográfica do Rio Roncador - Magé – RJ

Abstract

A contributor to Hydrographic Region V (RH-V) of the state of Rio de Janeiro, the Roncador River Basin suffers constant environmental impacts on its waters, as population growth and urban development in the municipality of Magé have caused increased degradation of this important water body. Irregular construction on its banks, inadequate and precarious sanitary infrastructure, have contributed to the inadequate disposal of domestic and industrial effluents. The river receives excess domestic sewage and suffers severe siltation with solid waste thrown into its bed, in addition to the removal of riparian vegetation resulting from occupations in its permanent preservation area, which boosts the erosion process from sediments transported to the smaller riverbed. Therefore, this process has contributed to recurrent flooding events during flood periods. The present study aims to create a mini atlas of the basin, moderating a mapping of the last 35 years, presenting the changes that were crucial to the degradation of the water body, pointing out which indicators can be taken into consideration for the management of water resources in the basin hydrographic in the coming years, especially in the case of extreme hydrological events. During the research, it was observed that the urban infrastructure class had the greatest increase in the basin area in the period researched, although in proportional terms, it is not as relevant, as the total urban area in 1985 was only 2.12 km², expanding in 2000 to an area of 6.09 km², gradually increased until 2020 where it reached a total area of 9.24 km², so that, in 35 years, it varied by 336.6% as can be seen in the variation chart. ln contrast, the dominant class, forestry formation, represented an area of 64.5 km² in 1985, reaching a total of 71.3 km² in 2020, which in turn, increased by 10.5% over the period studied. The focus of the research was to raise awareness by showing data, with the aim of producing considerations and collaborating as a source of perception in relation to the socio-environmental situation of the basin, and also, offering the public (public managers, private managers, researchers and related students) this considerable product to support responsible and competent decision-making and planning for the management of water resources within the territory of Magé and for Hydrographic Region - V of the state of Rio de Janeiro.