8Boers P C M. Nutrient emissions from agriculture in the Netherlands: causes and remedies [J]. Water Sci technol,1996(33): 183- 190.
9Soranno P A, Hubler S L, Carpenter S R. Phosphorus loads to surface waters: a simple model to account for spatial pattern of land use[J]. Ecological Applications, 1996, 6(3): 865 - 878.
10Tim U S, Jolly R. Evaluating agricultural nonpoint-source pollution using integrated geographic information systems and hydrologic/water quality model[J]. J Environ Qual,1994, 23(1): 25 - 35.
