Resumen
The background values of pollutants are becoming increasingly prominent in evaluating water quality and management, and their load and output characteristics are of great significance to the study of changes in the background values. Thus, this paper studies the estimation method for background pollutant fluxes into a river in a forested river source in northeastern China with deficient data or without data. Based on the results of a soak experiment and leaching experiment, as well as natural rainfall runoff experiments, the conversion relationship of the pollutant concentration in the medium was established, the transformation relationship of the pollutant concentration in the medium was established, its load into the river in a small watershed was estimated, and the estimation method was verified according to the measurements (average relative error: 20.5%). Then, the background pollutant loading into the river was calculated on a large scale by improving the pollutant output coefficient model and the universal soil loss equation (average relative error: 18.7%, 24.7%). The results show that the method mentioned above can better reflect the background pollutant loading into the river. This study provides an effective strategy to estimate the background pollutant loading into rivers in areas without data or with missing data, and also provides a theoretical basis for the study of zoning and the formulation of a water environment evaluation system based on background values.