Soil Pore Characteristics under Different Reclamation Modes for a Open-Pit Mine Area in Guangxi
The pore structure of reclaimed soil in the bauxite deposit of Guangxi plays a crucial role in soil reclamation quality,but its microstructure characteristics remain unclear.This study aimed to investigate the pore structure features of local-ly reclaimed soil by examining two reclamation modes:grassland reclamation(RG)and bare land reclamation(RW).X-ray CT scanning technology was employed to scan undisturbed 40 cm soil columns.The ImageJ software and its plugins,in conjunc-tion with the Avizo2020 rendering function,were utilized to obtain parameters that characterize the two-dimensional distribution and three-dimensional characteristics of soil pores.This allowed for the three-dimensional reconstruction,visualization and anal-ysis of soil pore structure.The results indicated a decrease in the quantity of two-dimensional small and medium pores in the soils of the RG treatment model compared to the RW treatment model,while there was a notable increase in the number of large pores in comparison to the RW treatment model.In the 0～20 cm soil layer,the pore surface density of the RG treatment was a-bout 30%lower than that of the RW treatment.In the 20～40 cm soil layer,the pore surface density and pore complexity of the RG treatment surpassed those of the RW treatment.The three-dimensional total pore number was significantly reduced in the RG treatment mode compared to the RW treatment mode.The porosity of the RG treatment(3.046%)was higher than that of the RW treatment(2.900%),indicating that the RW treatment resulted in more pores,but not larger ones.The connectivity of the RG treatment(0.399)exceeded that of the RW treatment(0.273).However,the tortuosity and specific surface area(1.329,4.026 mm-1)were lower in the RG treatment compared to the RW treatment(1.342,4.334 mm-1).In terms of three-dimensional structure,both treatments had a two-year reclamation time,resulting in a point-like distribution of pore struc-ture and displaying an inclined layered structure.However,compared to the RW treatment,the pores in the RG treatment were mainly distributed in macropores,with clearly visible elongated pores.This suggests that the RG-treated soil is progressing to-ward a more stable structure.Hence,within the soil reclamation process in Guangxi's open-pit bauxite mining area,the grass-land reclamation model proves more effective in enhancing soil structure and optimizing water and fertilizer transport channels compared to bare land reclamation,ultimately resulting in improved soil quality.
NETL
NSTL
万方数据
