Abstract:

Using physicallybased and parameterdistributed hydrological models,SWAT and Topmodel,hydrological effects caused by vegetation evolution within nearly 20 yeas in the headstream of Ganjiang was simulated.Based on the different characteristic of the models,different simulation steps were conceived.Changing of runoff in different years was simulated by SWAT,and changing of flux process in different years was simulated by Topmodel.The results shows:exclude the influence of climate change between the various scenes,only using different land use/cover and vegetation elements in the two models.Vegetation evolution in the Meijiang basin made the changing of hydrological effects apparently.In the whole basin,annual runoff was increased by 146% from 1987 to 2000.In its subbasin Qingjiang,the conflux speed was decreased,and peak discharge was decreased approximately by 5% in 7 inundations from 1995 to the year of 2000.The ecohydrological effects of vegetation change in Meijiang basin given strong evidence that the work of afforestation and land consolidation,also called as “Mountain Rivers and Lake Project” in Jiangxi Province,have good feedback effects to the ecological healthy of the basin.

Key words: distributed hydrological model/ vegetation evolution/ hydrology simulation/ Meijiang Basin