DILUTION GAUGING ON THE RECESSION LIMB: 2. THE INTEGRATION METHOD / Mesures par dilution sur la courbe de tarissement: 2. Méthode par intégration

Abstract

The application of dilution gauging techniques to natural streams and other variable flows incurs a systematic error caused by the change in discharge with time. On the recession limb of a hydrograph the change is usually smooth and gradual, and errors can be expected intuitively to be small. In a preceding paper the author investigated errors arising from this cause in the case of a constant rate tracer injection, and developed formulae for the calculation of bias from known values of the recession constant and the distribution of residence time in the gauging reach. This paper extends the theory of the residence time model to the case of a dilution gauging by the integration method, and presents analogous formulae for the errors.