Maria Nogueira Marques,Álvaro Marcio de Oliveira Santo,Adnívia Santos Costa,Felipo Obed Correia,Suelem Santos Gomes,Jose do Patrocínio Hora Alves, Instituto Tecnológico e de Pesquisas do Estado de Sergipe, , maria.marques@itps.se.gov.br
The São Francisco River basin is of major hydrological and economic importance for Northeast Brazil. It is responsible for 95% of the streamflow of the rivers that cross the State of Sergipe, and the catchment is the most important source of water for human supply in the State. The objective of this study was to perform the first evaluation (according to the Brazilian National Water Agency) of the water quality in the sub-basin of the lower São Francisco River in Sergipe using the Water Quality Index (WQI). The index uses nine water quality parameters, each assigned with a specific weighting established by the National Sanitation Foundation (NSF). Samples were collected in 2009 and 2010, at three month intervals, at five sites along the sub-basin. Of the 39 water samples evaluated, 72% were of good quality, 13% were acceptable, and 5% (each) were bad, very bad and excellent. These data represent an important baseline for future studies.
KEYWORDS: WQI, environmental assessment, monitoring.