How pore structure non-stationarity compromises flow properties representativity (REV) for soil samples: Pore-scale modelling and stationarity analysis

被引:30
作者
Gerke, Kirill M. [1 ]
Karsanina, Marina V. [1 ]
机构
[1] Russian Acad Sci IPE RAS, Schmidt Inst Phys Earth, Bolshaya Gruzinskaya 10-1, Moscow 123242, Russia
基金
俄罗斯基础研究基金会;
关键词
correlation functions; finite-difference Stokes solver; non-stationarity; permeability; pore-scale modelling; representative elementary volume; REV analysis; saturated hydraulic conductivity; statistical homogeneity; X-ray microtomography; ELEMENTARY-VOLUME ANALYSIS; POROUS-MEDIA; HYDRAULIC CONDUCTIVITY; COMPUTED-TOMOGRAPHY; TRANSPORT; SPACE; PERMEABILITY; SIMULATION; SYSTEMS; WATER;
D O I
10.1111/ejss.13055
中图分类号
S15 [土壤学];
学科分类号
0903 ; 090301 ;
摘要
Classic soil physics relies heavily on the concept of representative elementary volume (REV), which is necessary to perform upscaling from the studied soil samples and parameterize continuum scale hydrological models (e.g., based on Richards or Darcy equations). In this paper, we explore the boundaries of the classic REV concept and conventional representativity studies that claim REV for any given physical property, and that its values converge to a steady value with increasing sample volume. We chose two undisturbed soil samples of standard size from Ah and B horizons, subcropped two subvolumes within each of them and performed pore-scale flow simulations using binarized X-ray microtomography scans as input data. The volume of the simulation domains was 900(3)voxels, with a physical volume within two orders of magnitude of the whole soil core. Based on the 3D pore geometry images and the resulting flow velocity and pressure fields, we performed REV analysis for the saturated hydraulic conductivity and porosity. Although in general subvolumes showed classical REV behaviour (convergence of porosity andsaturated hydraulic conductance (K-sat)to plateau-like behaviour), their flow properties converged to different REV values. We also evaluated the stationarity of pore structures by computing the directional correlation functions to explain the observed non-unique behaviour. We concluded that neither of the studied samples can be considered to be representative due to their structural non-stationarity. We extensively discussed the implications of these results for the upscaling and parameterization of continuum-scale flow models. We argued that the plateau inK(sat)(or any other physical property) is a necessary, but insufficient, condition for the REV, which requires (at least) pore structure stationarity as an additional criterion. REV as a concept is much broader than previously anticipated and the possibility of establishing REVs in structured soils will require an analysis of tensorial flow properties with correct boundary conditions, multiscale soil structure imaging with stationarity analysis, and pore-scale simulations on fused multiscale images. Highlights K(sat)analysis within subvolumes showed classical REV behaviour but resulted in non-unique REVs for the soil samples studied Based on the stationarity analysis we argued that the conventional soil core samples studied were not REVs Plateau-like behaviour in physical properties is a necessary but insufficient condition for REV Soil structure information is necessary to properly establish REV or upscale flow properties
引用
收藏
页码:527 / 545
页数:19
相关论文
共 84 条
[61]   On the reconstruction of structural and functional properties in random heterogeneous media [J].
Schlueter, Steffen ;
Vogel, Hans-Joerg .
ADVANCES IN WATER RESOURCES, 2011, 34 (02) :314-325
[62]   Segmentation of X-ray microtomography images of soil using gradient masks [J].
Schlueter, Steffen ;
Weller, Ulrich ;
Vogel, Hans-Joerg .
COMPUTERS & GEOSCIENCES, 2010, 36 (10) :1246-1251
[63]   Representative-Elementary-Volume Analysis of Two-Phase Flow in Layered Rocks [J].
Sedaghat, Mohammad H. ;
Azizmohammadi, Siroos .
SPE RESERVOIR EVALUATION & ENGINEERING, 2019, 22 (03) :1075-1083
[64]   Simulation-Based Determination of Relative Permeability in Laminated Rocks [J].
Sedaghat, Mohammad H. ;
Gerke, Kirill ;
Azizmohammadi, Siroos ;
Matthai, Stephan K. .
EUROPEAN GEOSCIENCES UNION GENERAL ASSEMBLY 2016, 2016, 97 :433-439
[65]   A conceptual model of preferential flow systems in forested hillslopes: evidence of self-organization [J].
Sidle, RC ;
Noguchi, S ;
Tsuboyama, Y ;
Laursen, K .
HYDROLOGICAL PROCESSES, 2001, 15 (10) :1675-1692
[66]   Development and applications of the HYDRUS and STANMOD software packages and related codes [J].
Simunek, Jiri ;
van Genuchten, Martinus Th. ;
Sejna, Miroslav .
VADOSE ZONE JOURNAL, 2008, 7 (02) :587-600
[67]   The Impact of Multiple Freeze-Thaw Cycles on the Microstructure of Aggregates from a Soddy-Podzolic Soil: A Microtomographic Analysis [J].
Skvortsova, E. B. ;
Shein, E. V. ;
Abrosimov, K. N. ;
Romanenko, K. A. ;
Yudina, A. V. ;
Klyueva, V. V. ;
Khaidapova, D. D. ;
Rogov, V. V. .
EURASIAN SOIL SCIENCE, 2018, 51 (02) :190-198
[68]   Microtomographic analysis of pore space in a virgin soddy-podzolic soil [J].
Skvortsova, E. B. ;
Rozhkov, V. A. ;
Abrosimov, K. N. ;
Romanenko, K. A. ;
Khokhlov, S. F. ;
Khaidapova, D. D. ;
Klyueva, V. V. ;
Yudina, A. V. .
EURASIAN SOIL SCIENCE, 2016, 49 (11) :1250-1258
[69]   Nanoscale and multiresolution models for shale samples [J].
Tahmasebi, Pejman .
FUEL, 2018, 217 :218-225
[70]   On the influence of boundary conditions when determining transport coefficients from digital images of heterogeneous media [J].
Thovert, Jean-Francois ;
Mourzenko, Valeri V. .
ADVANCES IN WATER RESOURCES, 2020, 141