Based on point sources,such as sewage outfall,branches and water intakes and non-point sources,an integrated water environmental capacity model for one-dimensional river is established.

Hydrological segmentation provides an effective approach for quantifying non-point source(NPS) pollutant load.

Methodology for the Water Environment Impact Assessment of Highway Surface Runoff, which is one of the nonpoint source pollution, has been studied in this paper.

The nonpoint source pollution, which has played an important role on surface water pollution has been given much attention because of the effective controlling of the point source pollution.

Furthermore,the cause of the pollution leading to the reservoir eutrophication has been found,the leading pollution source is surface source pollution.