DOI: 10.5194/hess-20-4017-2016
Scopus记录号: 2-s2.0-84990199335
论文题名: Prediction of biopore- and matrix-dominated flow from X-ray CT-derived macropore network characteristics
作者: Naveed M ; , Moldrup P ; , Schaap M ; G ; , Tuller M ; , Kulkarni R ; , Vogel H ; -J ; , De Jonge L ; W
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2016
卷: 20, 期: 10 起始页码: 4017
结束页码: 4030
语种: 英语
Scopus关键词: Air permeability
; Dielectric properties
; Diffusion
; Forecasting
; Gas permeability
; Gases
; Groundwater flow
; Hydraulic conductivity
; Soil surveys
; Soils
; Water quality
; Air-filled porosities
; Empirical predictive models
; Network characteristics
; Organic matter content
; Predictive performance
; Saturated hydraulic conductivity
; Spatial variability
; X-ray computed tomography
; Computerized tomography
; air permeability
; airflow
; diffusivity
; flow pattern
; hydraulic conductivity
; organic matter
; porous medium
; prediction
; soil column
; soil texture
; tomography
; water flow
; Denmark
英文摘要: Prediction and modeling of localized flow processes in macropores is of crucial importance for sustaining both soil and water quality. However, currently there are no reliable means to predict preferential flow due to its inherently large spatial variability. The aim of this study was to investigate the predictive performance of previously developed empirical models for both water and air flow and to explore the potential applicability of X-ray computed tomography (CT)-derived macropore network characteristics. For this purpose, 65 cylindrical soil columns (6ĝ€cm diameter and 3.5ĝ€cm height) were extracted from the topsoil (5ĝ€cm to 8.5ĝ€cm depth) in a 15ĝ€mĝ€ × ĝ€15ĝ€m grid from an agricultural field located in Silstrup, Denmark. All soil columns were scanned with an industrial X-ray CT scanner (129ĝ€μm resolution) and later employed for measurement of saturated hydraulic conductivity, air permeability at ĝ'30 and ĝ'100ĝ€cm matric potential, and gas diffusivity at ĝ'30 and ĝ'100ĝ€cm matric potential. Distribution maps for saturated hydraulic conductivity, air permeability, and gas diffusivity reflected no autocorrelation irrespective of soil texture and organic matter content. Existing empirical predictive models for saturated hydraulic conductivity and air permeability showed poor performance, as they were not able to realistically capture macropore flow. The tested empirical model for gas diffusivity predicted measurements at ĝ'100ĝ€cm matric potential reasonably well, but failed at ĝ'30ĝ€cm matric potential, particularly for soil columns with biopore-dominated flow. X-ray CT-derived macroporosity matched the measured air-filled porosity at ĝ'30ĝ€cm matric potential well. Many of the CT-derived macropore network characteristics were strongly interrelated. Most of the macropore network characteristics were also significantly correlated with saturated hydraulic conductivity, air permeability, and gas diffusivity. The predictive Ahuja et al. (1984) model for saturated hydraulic conductivity, air permeability, and gas diffusivity performed reasonably well when parameterized with novel, X-ray CT-derived parameters such as effective percolating macroporosity for biopore-dominated flow and total macroporosity for matrix-dominated flow. The obtained results further indicate that it is crucially important to discern between matrix-dominated and biopore-dominated flow for accurate prediction of macropore flow from X-ray CT-derived macropore network characteristics. © Author(s) 2016. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/78719
Appears in Collections: 气候变化事实与影响
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作者单位: Institute of Biological and Environmental Sciences, University of Aberdeen, King's College, Aberdeen, United Kingdom; Department of Agroecology, Faculty of Science and Technology, Aarhus University, Blichers Allé 20, Tjele, Denmark; Department of Civil Engineering, Aalborg University, Sohngaardsholmsvej 57, Aalborg, Denmark; Department of Soil, Water and Environmental Science, University of Arizona, 1177 E. 4th Street, Tucson, AZ, United States; Department of Electrical and Computer Engineering, University of Arizona, 1230 E Speedway Blvd., Tucson, AZ, United States; Department of Soil Physics, Helmholtz Center for Environmental Research-UFZ, Theodor Lieser Straße 4, Halle (Saale), Germany
Recommended Citation:
Naveed M,, Moldrup P,, Schaap M,et al. Prediction of biopore- and matrix-dominated flow from X-ray CT-derived macropore network characteristics[J]. Hydrology and Earth System Sciences,2016-01-01,20(10)