The Impact of Typical Forest Vegetation Types on Slope Runoff in Three Gorges Region

The vegetation and precipitation are the major factors which determine runoff and sediment yield on the basis of certain terrain.The fixed observation on runoff ground in farmland and 4 runoff grounds in natural forestland had been conducted in Mt.Junyunshan in Chongqing from 2005 to 2006.The results showed that forest vegetation could decrease surface runoff to some extent,and rainfall had impact on slope runoff in earlier stage;the slope runoff peak flow corresponded to rainfall intensity,the runoff change range of Masson Pine and evergreen broadleaved forest was comparative small,while that of bamboo forest and evergreen broadleaved shrub was big;underground runoff depth corresponded to rainfall,which reflected prophase rainfall had impact on underground runoff;the general trend of mixed conifer-broadleaved forest,evergreen broadleaved forest and shrub was that it increased with rainfall's increasing,but bamboo forest and farmland deceased with rainfall's increasing.