Historical land use scenarios for 1985

1995

and 2000 were analyzed to track land use change of Taihu basin by TM/ETM image explanation. A cell-based non-point source pollution model is developed by combining the distributed hydrological model with the runoff concentration parameters of different land use types

and nitrogen utputs response of land use change are estimated by simulating the runoff volume and nitrogen fluxes usinglong-term rain records from 1980 to 2000. The results express that the modeled runoff volume and nitrogen outputs match well with the observed ones. For the entire basin between 1985 and 2000

the urban area increased about 40.38%

about 3.88% of the whole basin area. The land use changes result in runoff volume increase of 4.11% on average. Total nitrogen outputs increase 5.35% on average and 21.26% on maximum respectively. Nutrient output response varies according to the extent of land use changes in different parts of the basin and rain feature. In Suxichang and Pudongpuxi sub-regions

with more extent of land use changes

total nitrogen outputs increase 17. 11% and 10.72% on average respectively

and 60.43% and 28.68% on maximum.