VARIABILIDADE ESPACIAL DE PARÂMETROS E INDICADORES DE QUALIDADE DA ÁGUA NA SUB-BACIA HIDROGRÁFICA DO IGARAPÉ SÃO FRANCISCO, RIO BRANCO, ACRE, BRASIL VARIABILIDAD ESPACIAL DE PARÁMETROS E INDICADORES DE CALIDAD DEL AGUA EN SUBCUENCA HIDROGRÁFICA DEL IGARAPÉ SÃO FRANCISCO, RIO BRANCO, ACRE, BRASIL SPATIAL VARIABILITY OF WATER QUALITY PARAMETERS AND INDICATORS IN THE SÃO FRANCISCO STREAM SUB-BASIN, IN RIO BRANCO, ACRE, BRAZIL

It is important to assess water quality, as well as its vulnerability to human activity, towards water resources management, globally discussed, and to a lesser extent, seasonally. The aim of this work is to evaluate the water quality parameters along the Sao Francisco River, correlating them to possible sources of pollution, especially derived from anthropization, and to observe seasonal variations in these parameters. Methods involved collecting subsurface water samples and assessing pH, dissolved oxygen, electrical conductivity, turbidity, total dissolved solids, total nitrogen, total phosphorus, biochemical oxygen demand, chemical oxygen demand and fecal coliform bacteria. Main components analysis was used for grouping sampling sites. No aggregation tendencies were found for the axes of sampling sites axes in both studied periods.