Urban surface pollutant is now recognized as a major source of urban non-point pollution

thus

it is a key problem to scientifically understand and compute surface pollutants. In order to obtain the build–up law

starting in May

2006

a study was conducted to measure surface pollutants from representative land uses types in Zhenjiang

Jiangsu Province. It is shown that surface pollutants increase to the maximum value gradually and change with the periodic variation. Based on the storage-input-output balance principle

the input speed coefficient and removal rate coefficient are introduced to establish the build -up model of surface pollutants. By fitting with the measured data and comparing with other models

the precision of the model is accurate

and the calculated results can be used as the input of the wash-off model

which provides the scientific basis for non-point source pollution control and management.