20 MRB Signatures of X-Ray CT Images for Estimating Soil Hydraulic Conductivity
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- Ris (Zotero)
- Reference Manager
Recent advances in application of X-ray computed tomography (CT) for evaluation of soil properties have added new research tools for investigating structural features. Objectives of this study were to evaluate CT scan images using the Multiple Resolution Blanket (MRB) method and relate observed signature properties with soil saturated hydraulic conductivity. Forty intact samples taken at four depths were scanned at 7 mm intervals throughout each core to provide 8 scans per sample. Each scan was scaled so that CT numbers ranged from 0 to 255 relative attenuation, creating a 256 by 256 by 256 volume. The MRB method uses a theoretical blanket of varying thickness (k) to determine topological signatures representing variability. Signature graphs were divided into three regions (k < 0.8 mm, 0.8 < k < 3.5 mm, k > 3.5 mm) for analysis; these regions corresponded to relatively small, intermediate and large pore size characteristics. Regression slopes for the middle region (0.8 < k < 3.5 mm) and regression intercepts for the third region (k > 3.5 mm) were highly correlated with saturated hydraulic conductivity (r = 0.64). This study illustrates how X-ray CT images from soil cores can be evaluated using an image analysis technique and correlated with soil physical properties.