As cidades e as águas: uma abordagem metodológica das vulnerabilidades socioambientais dos rios Araguaia e das Garças, nos municípios de Barra do Garças, Pontal do Araguaia e Aragarças.

Abstract

The banks of urban rivers are peculiar because of their great environmental importance and its specific characteristics resulting from an anthropic context. In this sense, the scope of this research is to propose a methodological model approach to social and environmental vulnerabilities in Araguaia and Garças rivers, through an urban-environmental perspective; and has as its spatial area the cities of Barra do Garças and Pontal do Araguaia in Mato Grosso, and Aragarças in Goiás. Therefore, the methodology encompassed different geographical divisions in the relationship of rivers to these cities, including: a) the city, with the mapping of its presente social and environmental vulnerability levels by applying twenty-three socioeconomic indicators and two environmental indicators; b) the sub-basins with indicators that work to influence the degree of soil sealing and surface runoff; c) the riverbanks, using two indicators in the dimension of use and occupation of land, three indicators on the river dimension and two indicators in the environmental dimension. Through deductive method and qualitative and quantitative research, it was found that the lack of an interface between urban and environmental aspects when dealing with banks of urban rivers and their sub-basins contributes to environmental degradation of hydrous bodies and for the increase of environmental vulnerability areas. Regarding the environmental vulnerability, it was found that the geomorphological environmental indicators and those related to the risk of flooding influenced the environmental vulnerability index at the highest levels. With regard to the sub-basins, in the areas already urbanized, the soil sealing level and the time of concentration of the sub-basins showed levels "medium to high" which is worrying due to the relation of these indicators to the growth of flows and runoff volume and, thereby, increased frequency of flooding. As for the banks of the rivers in the study area, there were the urbanization impacts on the fluvial course, from the suppression of riparian areas to erosion and siltation of these points. The economic, demographic and social changes inherent in the process of urbanization were responsible in reducing vegetation covering, resulting in impacted or damaged points. This process has occurred without many strategies with an integrative perspective of urban and environmental aspects, both in the planning process of use and occupation and in interventions on the riverbanks; corresponding to the hypothesis of the research that the adoption of an integrative perspective of urban and environmental aspects in planning the banks of urban rivers and their sub-basins contributes to the conservation of the water body and its banks, as well as in reducing the environmental vulnerability of the cities. Thus, it is believed that the fluvial systems and the urban processes should be integrated, seeking convergence points through conciliation between the numerous private interests and environmental protection without degrading the natural environment by impacts on stretches of water bodies.