DISPERSION OF SOLUBLE POLLUTANTS IN NONUNIFORM RIVERS .1. THEORY

An analytical framework is developed to represent the solute dispersion behaviour of a river whose local average velocity, flow rate and dispersion characteristics vary along its length. A coordinate transformation through which the concept of a dispersion coefficient is replaced by that of a characteristic time allows the use of dimensionless equations. By measuring concentration-time profiles at various stations downstream from a point where a slug of pollutant is instantaneously released it is possible to determine the variation of the characteristic time of the river along its length. © 1979.