Evaluation of a Rating Curve for Pollutant loads in Rivers without Measured Water Quality under Flood Conditions

Abstract

To accurately evaluate pollutant load in high-flow conditions in rivers without measured water quality, we present a new rating curve for pollutant loads (L=aQ^b , b: coefficient) in which non-dimensional discharge Q and pollutant load L are introduced. The present method adopts correlation between the coefficient b in the rating curve and land use in watersheds. We apply the present method to evaluate the coefficient b and pollutant loads in several types of rivers. The results indicate that the pollutant load evaluated by the present method are acceptable agreements with observed data, showing the fundamental performance of the present method to evaluate pollutant load in flooding conditions in rivers without measured data of water quality.