Caracterização dos impactos ambientais na bacia hidrográfica do Espírito Santo/Coari (AM) no período de 1990 a 2010

Abstract

The present study contextualizes the prioress occupation of the Espírito Santo Watershed, in Coari Municipality, Amazonas State, from 1990 to 2010. It analyses the migratory influences of the Petrobrás work front in two distinct moments: the first one during the Solimões Port construction and the second, during Coari-Manaus gas duct construction. That was intending to understand the backgrounds of the watershed occupation. The watershed was defined as a spatial unity of environmental planning which relates the physical, economical and social aspects. The aim of this study was to characterize the environmental impacts on that watershed and to analyze how the environmental and aquatic legislation are applied on the Permanent Preservation Areas PPA on the urban perimeter. Although Coari Municipality is a small town, with approximately 73,475 in habitants, it already presents relevant impacts concerning the aquatic supplies. The present study showed that the pH of 7 water sampling stations, out of 8, were between 7.06 and 6.63, which represent water contamination, according to the Water Quality Index. That may be related to the fact that 73% of the domestic effluents have no treatment. The majority of the population living on the PPAs has lived there for 1 to 10 years, totalizing 56% of the population in the Espírito Santo watershed. That population living in the PPAs corresponds to two migratory cycles of Petrobrás work front, in 1996 and 2008. Even though the PPAs are legally instituted as natural vulnerable areas, 54% of them were occupied during the last 20 years. The environmental impacts from this occupation have brought prejudices to the resident population and 52% of the most frequent illness is water-borne diseases. The flooding affect about 90% of the watershed population and, each year, the frequency of the river channel overflow has increased. Upon this background, this research uses the watershed as an environmental planning unity that integrates every constructor s agents from those natural risks susceptible areas.