Using X-ray CT scanning to quantify the microstructural characteristics of soil pore in mining areas along a reclamation time

The quantification of complex pore structures under different reclamation times and their relationships to rec-lamation time remains elusive. The authors have compared the soil pore microstructures under 0 a (CK treatment),3 a ( FK3 treatment) and 10 a (FK10 treatment). Intact soil columns were taken from 200 mm depths with PVC tube (50 mm in diameter,200 mm in height) in Zhaogu subsidence area,Huixian County,Henan Province,China. The soil col-umns were scanned using X-ray computed tomography at a voxel resolution of 0. 23 mm×0. 23 mm×0. 20 mm. After the reconstruction by the Image J software and its plug-in,the characteristics of macropore networks were quantified, including soil pore number,circle rates,fractal dimension and Euler value. The analysis of variance indicated that the reclamation time significantly influenced the spatial and temporal hierarchy and sequence. The porosity,pore number,circle rates,fractal dimension and Euler value were of greater under CK and FK10 than FK3. From the reclamation soil profile,the soil pore structure at depths 0-30 mm was still in a disordered state,while the 40-80 mm soil layer tended to be stable. Soil pore number in size order were FK3>CK>FK10 at depths 0-30 mm and CK>FK3>FK10 at depths 40-80 mm. The change trend of soil porosity was similar to that of soil pore number at depths 0-200 mm. The fractal dimension of CK and FK10 was increased significantly (P