Physical and chemical variables of strems of Ibiuna, São Paulo State, 23º 58’ S and 47º 17’ W

Abstract

The paper describes tree first order streams of the Paraná River Basin through measurement taken out from April/1981 to March/1984. The studied variables showed the following median values: water temperature,18.0°C; color, 95 mg/L-Pt; turbidity, 29 FTU; electrical conductivity, 36 µS/cm; pH 6.4; alkalinity, 16.03 mg/L -CaCO₃; hardness, 16.0 mg/L-CaCO₃; chlorine, 3.61 mg/L; iron, 1.27 mg/L; silica, 9.90 mg/L; oxidability 3.35 mg/L; ammonia, 0.41 mg/L; nitrite, zero; nitrate, 0.11 mg/L; phosphate, 18 µg/L; dissolved oxygen, 7.65 mg/L and oxygen saturation, 93%. The measured variables does not showed significant differences between the tree streams. The rainy-warm season (October-March) included the highest values, but, besides temperature, the temporal differences showed no significance.