Dispersion of pollutants in watercourses intercepted by highway BR-050, in the Triângulo Mineiro region, Minas Gerais, Brazil

Models based on the diffusive-advective equations are valuable tools for forecasting of contamination levels downstream from spill points. These models require field parameters for validation. The longitudinal dispersion coefficient E L , which translates the transport potential of dilute pollutant is amongst the most important parameters. Based on field techniques using saline and fluorescent tracers, this study determined the E L in three streams intercepted by highway BR-050, all located in the Paranaiba River Basin. The discrepancy ratios ( Rd ) of some experimental methods and equations reported in the literature were analyzed and compared with the standard routing procedure. Comparing the results of the Moment (statistical), the Chatwin, the peak concentration and the crown concentration methods, the lowest discrepancy ratios were obtained for the latter two methods. Ribeiro, Silva, Soares, and Guedes (2010) also showed that the peak concentration and the crown concentration methods produce the lowest discrepancy ratios. The analysis of contamination scenarios clearly illustrates the direct relationship between pollutant transport capacity and water discharges in natural watercourses.