HYDROGEOCHEMICAL EVALUATION IN SELECTED SITES OF THE MARACANÃ RIVER WATERSHED (NORTHEAST - PARÁ, BRAZIL)

Abstract

The investigated area has a dimension of approximately 3,500 km2, included the River Maracanã watershed (northeast Pará, Brazil). For its environmental characteristics represent important regional sector, mainly by farming activities and harvesting of fishing. This area can be subdivided areas of riverheads, transition area and estuarine area, with larger flows of tides. The geochemical interpretation shows that in areas of riverheads it is found the lowest values of pH (4.8) and electrical conductivity (21.8 uS.cm-1), mainly in the rainy season. However, the high values of pH (7.9), electrical conductivity (31,300 uS.cm-1) and chlorophyll-a (49.3 mg.m-3) have been quantified in the estuarine area in dry season, showing the influence of ocean waters and phytoplankton. The seasonality local effectively affects the social dynamics and the sustainability of traditional people communities, for instance, a diversity of fish species that are caught throughout the annual cycle. Thus, the variables discussed are important to develop a strategic plan to achieve the local and regional sustainability of the studied watershed.