Avaliação da qualidade das águas de córregos urbanos reabilitados em Belo Horizonte

Abstract

Environmental rehabilitation of urban water courses is a recent development in Brazil, but it has been practiced in developed countries since the 1970s. Bringing these practices to Brazil is a great challenge, since in general urban streams are channeled and used for effluent disposal without proper treatment. The Drenurbs Program, implemented in the city of Belo Horizonte since 2003, is one of the first urban waterway rehabilitation initiatives in Brazil, with practical results in 3 hydrographic basins. The objective of this study is to evaluate the effectiveness of this program in the Baleares, Primeiro de Maio e Nossa Senhora da Piedade streams, between 2006-2008, 10 years after the rehabilitation program. An observaional study was conducted trough analysis of variance (ANOVA) factorial considering 3 phases of the rehabilitation project as treatment levels: (i) before the interventions (2003-2006); (ii) immediately after the interventions (2008-2011); and (iii) 10 years after the interventions (2018-2019), using the the 3 streams as independent variables. The experiment was conducted separately for the dry (April-September) and rainy (October-March) seasons. In each sampling effort 9 physical and chemical parameters that make up the Water Quality Index, in addition to the index itself, were measured and compared to the national standard to measure the improvement of water quality. In general, there has been a progressive improvement in most of the parameters evaluated, especially in the IQA, and the time periods after rehabilitation were significantly different from the period before the rehabilitation. Given the results of this initiative, these rehabilitation efforts in Belo Horizonte can support the implementation and evaluation of future projects aimed rehabilitate urban rivers, which are feasible in the Brazilian reality.