Degradação de ambientes fluviais por ação antropogênica: novos cená(rios) na bacia de drenagem do Rio Novo (ES)

Abstract

Due to the various utilities offered by rivers and other associated river environments to human beings, these agents establish relationships of notoriety throughout history. However, it is in historically more contemporary times that these relationships, in addition to gaining new materializations, condition the unprecedented worsening of the environmental degradation of rivers, notably in the urban context where they are often taken as obstacles to the growth of the cities and disregarded in the urban landscape. Therefore, the main objective of this research was to investigate the degradation of river environments in the Rio Novo Drainage Basin (RNDB), located in the interior of the state of Espírito Santo, Brazil, by anthropogenic action driven by changes in the pattern of land use and cover in the basin. The theoretical-conceptual basis adopted the use of Ashmore’s “sociogeomorphology” (2015) to think about rivers as results of the interrelations established between physical-natural and socioeconomic processes and dynamics, which was expanded to drainage basins. In turn, the methodology consisted of the elaboration of thematic maps from the manipulation of vector and raster data in GIS environment for analysis and discussion of physical and social aspects of the basin and the proposal of a Rapid Assessment Protocol (RAP) model as an accessible and a low cost tool for preliminary measurement of the environmental framework of fluvial systems in front of consolidated monitoring stations and which was adapted to the RNDB reality, as well as the framing of the score assigned during the application of the RAP on an environmental quality scale. The RAP was applied in thirteen points located in urban perimeters of the basin, where in eight of them the result was "intermediate"; in four of them the result was "good"; and in just one of them the result was "great". It was verified, from the fieldwork and the bibliographic survey, several examples of direct and indirect anthropic interferences in several river environments of the basin, including rectifications, changes and impediment to development of rivers cross-sections, banks concreting, interbasin transfer, fluvial landfills, emission of domestic effluents and inadequate disposal of solid waste that lead to the increasing environmental degradation of the fluvial system in question