Abstract:
According to the observations of precipitation and runoff in Xiangshuihe Watershed of Liupan Mountains on Jun.-Oct.,2004 and 2005,the effect of slope aspect,altitude and vegetations type on runoff is studied by GIS technique and SPSS software.The results of runoff coefficient for different vegetation types show such an descending order as plantation forest,shrub forest,natural forest,and sub-alpine meadow.The descending order of runoff coefficient for different altitude ranges is lower altitude area(2 060-2 350 m),middle altitude area(2 350-2 640 m),higher altitude area(2 640-2 930 m).With the increasing of altitude,the runoff coefficient in the natural forests decreases at the beginning and then increases,while the runoff coefficients for plantation and shrub forests have the trend of increasing at the beginning and then decreasing.However,the runoff coefficient for subalpine meadow keeps an increasing trend from middle to higher altitude.According to the slope aspects,the runoff coefficient for southern slope is the highest and that for eastern slope is the lowest.