基于CT扫描的露天煤矿排土场重构土壤孔隙三维重建及定量表征
Three-dimensional reconstruction and quantitative characterization of reconstruction soil pore at opencast coal mine dump based on CT scanning
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摘要: 土壤孔隙对水分、养分的运移起着重要作用,重构土壤孔隙状况反映着复垦土壤质量的高低。通过对安太堡露天煤矿不同复垦年限排土场重构土壤(23,20,0 a)以及原地貌土壤进行CT扫描,获取土壤孔隙信息,基于Matlab平台进行土壤孔隙分布的三维重建,并搜索土壤孔隙团的个数及每个孔隙团的体积大小,计算土壤孔隙度,实现了重构土壤孔隙状况的定量表征。结果表明:随着复垦年限的增加,重构土壤孔隙度、连通性得到显著性提高,其中复垦23 a土壤孔隙状况最好,50~75 cm土层孔隙度最大,为23. 92%,其次为复垦20 a土壤,25~50 cm土层孔隙度最大,为14. 58%,未复垦土壤因受大型机械的压实作用,孔隙连通性最差,3个土层孔隙分布比较均一,孔隙度都接近于3%;孔隙团个数、最大孔隙团体积与孔隙度都符合较好的线性关系,随着孔隙度的增加,孔隙团的个数呈减小的趋势,最大孔隙团体积呈递增趋势;每个重建区域除最大孔隙团外,其余团的体积非常小。为了改善未复垦排土场土壤孔隙状况,应尽快进行植被恢复。Abstract: Soil pore plays an important role in migrating water and nutrient,the pore of reconstructed soil reflects the quality of reclaimed soil. In this paper,the reconstruction soil of different reclamation years at Antaibao opencast coal mine including 23 years,20 years and 0 years old and the soil of original landform were chosen to be scanned to obtain the information of soil pore. Soil pore distribution in three-dimension was reconstructed at matlab platform,then quantitative characterization was realized by searching the number of soil pore groups and the volume of each group. The soil porosity was also calculated. The results indicate that the porosity and connectivity of reconstructed soil had been significantly improved as reclamation years increasing. The condition of reclaimed soil pore of 23 years old is the best,the porosity of 50-75 cm layer is the largest,and its value is 23. 93% . The second one is the 20 years old soil,the porosity of 25-50 cm layer is the largest,and its value is 14. 58% . The connectivity of unreclaimed soil pore was the worst as compacted by the large mechanism. The porosity of three soil layers are all close to 3%,the distribution of the pore is relatively uniform. The number of pore groups and the volume of the largest pore group all have a good linear relationship with the porosity. With the increasing porosity,the number of the pore groups is decreasing,the volume of the largest pore group is increasing. The volume of pore groups is very small except the largest one. In order to improve the condition of pore of unreclaimed soil,the vegetation restoration should be carried out as soon as possible.