Macropores Study on Vadose Zones of Hillslope Based on Fractal Dimension

In this study,two soil cores of 25 cm in width,25 cm in length,and 50 cm in height from vegetated slope in Panhe,Yunnan Province,China were collected as research objects.Base on X-ray computed tomography,a series of slice images were collected.According to CT value,the macropores can be separated from soil matrix for typical slices.Abnormity characteristics were also studied by means of fractal dimension(box-counting method)analysis.Results show that there is a positive correlation between macroporosity and their box-counting dimension which decreases with soil depth,but macroporosity only characterize the proportion of macropores;the abnormity could be represented by box-counting dimension.In addition,cumulative macroporosity increases in power function along with the pore diameter when dimension is constant.