Moment-Based Method for Identification of Pollution Source in Rivers

Abstract

Identification of unknown pollution sources is essential to environmental protection and emergency response. This paper presents a moment-based method for identification of source location and quantity of accidental pollution along a river. The first two moment equations are derived through the Laplace transform of the variable residence time (VART) model. While the first moment in combination with observed data is used to determine the location of pollution source, the second moment in combination with observed data is employed to estimate the total mass (quantity) of released pollutant. The two moment equations are tested using 23 sets of conservative tracer injection data collected from 23 reaches in 5 rivers with the reach length ranging from about 3 to 300 km. Results show that the first moment equation is able to predict the pollution source location with a percent error less than 18% in general. The percent error involved in the estimation of the corrected total mass is commonly less than 20%. While developed and tested using conservative tracer data, the moment-based method can also be applied to tracking the source location of reactive pollutants, providing a simple yet effective tool for pollution control and environmental management.