Estimation Model of River Pollutant Discharge Rate Based on One-Dimensional Water Quality Model

This paper studies the estimation of river pollutant discharge rate. With comprehensive analysis of primary factors impacting water quality, say pollutant concentration, water flow velocity, water discharge amount and natural degradation, we build an estimation model of river pollutant discharge rate based on one-dimensional water quality model. Considering that the distribution of waste outlets along a river is indeterminate, we assume that waste outlets of a river section concentrate at the beginning or the ending of the section. Under this assumption, the maximal discharge rate and the minimal discharge rate of the waste outlets are computed, and their average value yields the discharge rate of the river. Take the Yangtze River for example. Using the practical testing data from observing stations along the mainstream, we determine the origin and the discharge rate of ammonia nitrogen pollutant. The example shows that both the model and the analysis method are effective and adaptable.