Análise da evolução na sustentabilidade da bacia hidrográfica do Rio Poxim, Sergipe

Abstract

Faced with the growing concern about water resources, analyzing their quality is a central action for planning. Such an assessment must consider the different contexts in which each water body is inserted. For this reason, river basins are considered territorial and planning units, the scene of important ecological, social and economic interactions. The Poxim river basin has a total area of 348.88 km², partially covering six cities in the state of Sergipe. The river historically has a central position in the issue of public supply, which means that the river faces a great demand for consultative uses and suffers from the effects of the inadequate use of water resources. Environmental diagnoses in watersheds can be optimized with the help of tools such as indexes and indicators capable of recognizing different social, economic and institutional patterns, thus reflecting the different relationships between the physical, biotic and anthropic environment. In the case of the present work, the Watershed Sustainability Index (WSI) was selected to assess the level of sustainability of the Poxim planning unit in two time intervals (2010 – 2015) and (2015 – 2020). This methodology analyzes parameters of the hydrological, environmental, social and political dimensions through a Pressure — State — Response matrix. The WSI for the first period (2010 – 2015) was 0.54 indicating an intermediate level of sustainability, while in the second five-year period it was 0.80, preserving the basin level at intermediate. Over the 10 years it has been observed that the hydrological dimension is historically the main limiting factor of sustainability in Poxim, mainly in the quantitative aspect, followed by insufficient investment in Integrated Management of Water Resources. The social indicators showed the same results for both periods studied, which may indicate a stagnation in aspects related to the quality of life of the population present there. Environmental indicators remained stable for both years, with the exception of the Response indicator, which showed significant progress in terms of conservation areas and good management practices. Regarding political indicators, it was observed that the state of Sergipe has a very complete legislation, thus being able to benefit this planning unit, however, the presence or absence of laws and institutions do not guarantee the adequate management of water resources, which can be perceived in the case of Poxim. The WSI can be used as a support for environmental diagnoses and decisionmaking processes, identifying current problems and guiding future actions. However, the wide dissemination of data is essential for the proper application of this tool, not only in decision-making and academic spaces, but also to civil society.