Modeling non-point pollution based on interactions between flow path and landscape units
基于水流路径与景观单元相互作用的非点源污染模拟研究

This paper describes a simulation model for non\|point source pollution assessment at a landscape scale based on the interactions between landscape units during pollutant transport along the flow path. By differentiating the interactions into "pull" and "drag" effects, the loss of a pollutant to the receiving water body can be estimated. Thereafter, the spatial distribution of water quality conditions along the river channel is obtained based on flow accumulation values. We applied this model to four watersheds in Hailun of Heilongjiang in Northeast China. The modeling results were compared with observed data for ten storm events within two years, for which the simulated nitrogen and phosphorus concentrations correlated significantly with measured total nitrogen and particulate phosphorus concentrations. These results indicated that the method is able to describe the spatial and temporal distribution of nitrogen and phosphorus source pollution and water quality characteristics in a watershed. However, the simulated nitrogen and phosphorus concentrations were higher than the observed. Further improvement of the method with respect to qualitative water quality assessment is suggested.