[Estimation and Critical Source Area Identification of Non-point Source Pollution Based on Improved Export Coefficient Models: A Case Study of the Upper Beiyun River Basin].

Non-point source pollution(NSP) poses a great threat to water ecosystem health. The quantitative estimation of spatial distribution characteristics and accurate identification of critical source areas(CSAs) of NSP are the basis for its efficient and accurate control. The export coefficient model(ECM) has been widely used to assess NSP, but this model should be improved because it ignores pollutant loss in transport processes.

[Analysis of Spatial-Temporal Variation Characteristics of Potential Non-point Source Pollution Risks in the Upper Beiyun River Basin Using Different Weighting Methods].

Non-point source pollution has become an important factor affecting the aquatic ecological environment and human health, and the analysis of spatial-temporal variations in non-point source pollution risks is an important prerequisite for pollution control. Based on land-use and land-cover data from 1980 to 2020, the potential non-point source pollution index (PNPI) model was applied in the upper Beiyun River Basin using different weighting methods. The results showed that:① The potential risk of non-point source pollution is high in the southeast and low in the northwest of the basin.