RELATIONSHIP BETWEEN PRECIPITATION AND TURBIDITY IN WATER COURSES IN ESPÍRITO SANTO

Abstract

Water is an irreplaceable natural resource for the maintenance of life on Earth. For human consumption, the depreciation of its quality can have different consequences on public supply. Therefore, the objective was to relate turbidity with precipitation of 50 hydrographic basins whose sources are used for public supply in the State of Espírito Santo. Fifty points of adduction of raw water used in the treatment and supply to the public supply network were selected, using their monthly averages of turbidity of 48 months, from 2006 to 2008. The hydrographic basins were delimited using a hydrologically consistent digital elevation model, obtained in a GIS environment. Precipitation data were spatialized using the ordinary kriging geostatistical technique. A regression analysis was performed between turbidity and precipitation resulting in equations with R² between 0.01 and 0.89 for the entire period; R² between 0.01 and 0.96 for the dry season (April to September); and 0.04 and 0.88 for the rainy season (October to March). The relationship between Tr and Pm is a good indicator for predicting turbidity levels, but the use of longer analysis periods for greater accuracy of the adjustments is recommended.