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Applicability of the Reynolds equation for modeling fluid flow between rough surfaces
PROPERTIES:GENERAL a velocity optimization process, operating at fracture intersections, causes mass channeling at the network scale. (from Authors)
964035 Dual porosity fracture flow and transport W. Dershowitz & I. Miller, Geophysical Research Letters, 22(11), 1995, pp 1441-1444. This paper presents a dual-porosity, single permeability approach for evaluation of flow and transport in fractured rock. The fracture network flow approach is based on a generic matrix block similar to the method of Warren and Root (1963), applied to realistic fracture geometries. The solute transport approach is based on a probabilistic concept of matrix diffusion as a process of Brownian motion, implemented using a prohabilistic particle tracking technique. (from Authors) 964036 Challenging models for flow in unsaturated, fractured rock through exploration of m a l l scale processes R. J. Glass, M. J. Nicholl & V. C. Tidwell, Geophysical Research Letters, 22(11), 1995, pp 1457-1460. This paper provides examples of how recent advances in understanding of small-scale processes within discrete fractures may influence the behaviour of fluid flow in fracture networks and ensembles of matrix blocks sufficiently to impact the formulation of intermediate-scale effective media properties. It is also considered how these same small-scale processes could couple to produce a large-scale system response inconsistent with current conceptual models of flow through unsaturated, fractured rock. (from Authors)
964037 Applicability of the Reynolds equation for modeHug flmld flow between rough surfaces S. R. Brown, H. W. Stockman & S. J. Reeves, Geophysical Research Letters, 22(18), 1995, pp 2537-2540. Predictions of the Reynolds equation for flow between roughwalled surfaces have been compared to a more exact calculation of Navier-Stokes flow based on a lattice-gas automation method. Two-dimensional channels were constructed with an idealized sinusoidal roughness on each wall. Flow in the channels was studied for various amplitude to wave-length ratios of the roughness, surface separations, relative alignment or phase of the sinusoids, and Reynolds numbers. The Reynolds equation overestimates fluid velocity as the surfaces are placed together or the amplitude of the roughness increases relative to its wave-length. (Authors)
153A
satisfactory in predicting missing values for a short period of time. The simulation of soil moisture storage variation by the two physically based models was good. However, distribution of soil water content within the profile proved to be difficult to achieve. The coarseness of texture and the disturbed stratification hampered modelling. (from Authors) 964O4O Validation of an inverse numerleni model for interpretation of pumping tests and a study of factors influencing accuracy of results L. Lebbe & W. De Breuck, Journal of Hydrology, 172(I-4), 1995, pp 61-85. An inverse numerical model was developed for the interpretation of simple or multiple pumping tests in layered ground° water reservoirs. Use of a simplified representation of the flow system in the inverse model can cause erroneous estimates. Hydraulic parameter estimates obtained by fitting data from a single observation well to type curves can result in very different values for the parameters if the actual flow is different from the model from which the type curves are derived. These different values are not due to the heterogeneity of the formation as is often concluded in many pumping test analyses. The number of parameters that can be reliably estimated decreases and the joint confidence region of the estimates enlarges when the relative error of the observed drawdowus increases. (from Authors) 964041 Completing the pound-water model: 'we need more data' D. L. Rehmeyer, Environmental & Engineering Geoscience, 1(3), 1995, pp 353-358. An ideal system for subsurface geologic an-lysis would be non-intrusive, have the depth of penetration of RS, while offering the vertical resolution of GPR. Electromagnetic methods (EM) offer distinct advantages in helping to solve these problems: 1) they are non-intrusive, and 2) the technology to support EM probing-pulse generation, data collection - is well estabfished. Quaternary Resource Investigations, Inc. (QRI) has developed such a system. (from Author)
PROPERTIES OF ROCKS AND SOILS General 964042
964038
Further evidence of fractal structure in hydraulic conduc-
Genesis ami properties of collapsiMe soils. Proceedings of a workshop, LougkboroJtgh, April 1994
964039
ed E. Derbyshire, T. Dijkstra & I. J. Smalley, (Kluwer/Nato Scientific Affairs Division; NATO ASI Series C, Mathematical and Physical Sciences, 468), ISBN (hardback) 0 7923 3587 2, price D r 295.00 COS$199.00) (£130.00), 1995, 413 pp, index. Human activity continues to increase in regions underlain by collapsible soils, therefore hazards are increasing in both relative and absolute terms. The aim of this workshop was to identify goals in the study of the collapse process, propose working definitions of 'collapse', and to formulate collapse models as a key to soil treatment so as to enhance utilisation and diminish hazard. This volume contains 21 of the 27 papers presented at the workshop. (from Editors)
The use of lysimeters in the study of soft surface processes: applications J. Ahonen, S. Tattari, K. Granlund & J. Soveri, Geophysica, 31(1), 1995, pp 51-69. Four lysimeters situated in central and southern Finland were used to study peroolation processes. Model simulations were done with two different physically sound soil water models and with a transfer function model. The physical soil water models failed to predict, and thus failed to replace, missing daily percolation values. A transfer function model was
964043 Memory effects In rocks (review) V. S. Yamshchikov, V. L. Shkuratnik & A. V. Lavrov, Journal of Mining Science, 30(5), 1994(1995), pp 463-473; translated from: Fiziko-Tekhnieheskie Problemy Razrabotki Poleznykh Iskopaemykh, 30(5), 1994, pp 57-69. The ability to store and reproduce information about experienced natural-genetic and technogenic actions is one of the most common qualitative characteristics of rocks and,
tivity distributions F. J. Molz & G. K. Boman, Geophysical Research Letters, 22(18), 1995, pp 2545-2548. Past rescaled range analyses of porosity and hydraulic conductivity (K) distributions have indicated the presence of long-range correlations in the data typical of the related stochastic functions known as fractional Gaussian noise and fractional Brownian motion. New K data analyzed herein lend further support to this notion. Analysis supports the existence of fractal-like K fields similar to those visualized by Ncuman [1990, 1994]. (from Authors)
modelling and measurement
964035 Dual porosity fracture flow and transport W. Dershowitz & I. Miller, Geophysical Research Letters, 22(11), 1995, pp 1441-1444. This paper presents a dual-porosity, single permeability approach for evaluation of flow and transport in fractured rock. The fracture network flow approach is based on a generic matrix block similar to the method of Warren and Root (1963), applied to realistic fracture geometries. The solute transport approach is based on a probabilistic concept of matrix diffusion as a process of Brownian motion, implemented using a prohabilistic particle tracking technique. (from Authors) 964036 Challenging models for flow in unsaturated, fractured rock through exploration of m a l l scale processes R. J. Glass, M. J. Nicholl & V. C. Tidwell, Geophysical Research Letters, 22(11), 1995, pp 1457-1460. This paper provides examples of how recent advances in understanding of small-scale processes within discrete fractures may influence the behaviour of fluid flow in fracture networks and ensembles of matrix blocks sufficiently to impact the formulation of intermediate-scale effective media properties. It is also considered how these same small-scale processes could couple to produce a large-scale system response inconsistent with current conceptual models of flow through unsaturated, fractured rock. (from Authors)
964037 Applicability of the Reynolds equation for modeHug flmld flow between rough surfaces S. R. Brown, H. W. Stockman & S. J. Reeves, Geophysical Research Letters, 22(18), 1995, pp 2537-2540. Predictions of the Reynolds equation for flow between roughwalled surfaces have been compared to a more exact calculation of Navier-Stokes flow based on a lattice-gas automation method. Two-dimensional channels were constructed with an idealized sinusoidal roughness on each wall. Flow in the channels was studied for various amplitude to wave-length ratios of the roughness, surface separations, relative alignment or phase of the sinusoids, and Reynolds numbers. The Reynolds equation overestimates fluid velocity as the surfaces are placed together or the amplitude of the roughness increases relative to its wave-length. (Authors)
153A
satisfactory in predicting missing values for a short period of time. The simulation of soil moisture storage variation by the two physically based models was good. However, distribution of soil water content within the profile proved to be difficult to achieve. The coarseness of texture and the disturbed stratification hampered modelling. (from Authors) 964O4O Validation of an inverse numerleni model for interpretation of pumping tests and a study of factors influencing accuracy of results L. Lebbe & W. De Breuck, Journal of Hydrology, 172(I-4), 1995, pp 61-85. An inverse numerical model was developed for the interpretation of simple or multiple pumping tests in layered ground° water reservoirs. Use of a simplified representation of the flow system in the inverse model can cause erroneous estimates. Hydraulic parameter estimates obtained by fitting data from a single observation well to type curves can result in very different values for the parameters if the actual flow is different from the model from which the type curves are derived. These different values are not due to the heterogeneity of the formation as is often concluded in many pumping test analyses. The number of parameters that can be reliably estimated decreases and the joint confidence region of the estimates enlarges when the relative error of the observed drawdowus increases. (from Authors) 964041 Completing the pound-water model: 'we need more data' D. L. Rehmeyer, Environmental & Engineering Geoscience, 1(3), 1995, pp 353-358. An ideal system for subsurface geologic an-lysis would be non-intrusive, have the depth of penetration of RS, while offering the vertical resolution of GPR. Electromagnetic methods (EM) offer distinct advantages in helping to solve these problems: 1) they are non-intrusive, and 2) the technology to support EM probing-pulse generation, data collection - is well estabfished. Quaternary Resource Investigations, Inc. (QRI) has developed such a system. (from Author)
PROPERTIES OF ROCKS AND SOILS General 964042
964038
Further evidence of fractal structure in hydraulic conduc-
Genesis ami properties of collapsiMe soils. Proceedings of a workshop, LougkboroJtgh, April 1994
964039
ed E. Derbyshire, T. Dijkstra & I. J. Smalley, (Kluwer/Nato Scientific Affairs Division; NATO ASI Series C, Mathematical and Physical Sciences, 468), ISBN (hardback) 0 7923 3587 2, price D r 295.00 COS$199.00) (£130.00), 1995, 413 pp, index. Human activity continues to increase in regions underlain by collapsible soils, therefore hazards are increasing in both relative and absolute terms. The aim of this workshop was to identify goals in the study of the collapse process, propose working definitions of 'collapse', and to formulate collapse models as a key to soil treatment so as to enhance utilisation and diminish hazard. This volume contains 21 of the 27 papers presented at the workshop. (from Editors)
The use of lysimeters in the study of soft surface processes: applications J. Ahonen, S. Tattari, K. Granlund & J. Soveri, Geophysica, 31(1), 1995, pp 51-69. Four lysimeters situated in central and southern Finland were used to study peroolation processes. Model simulations were done with two different physically sound soil water models and with a transfer function model. The physical soil water models failed to predict, and thus failed to replace, missing daily percolation values. A transfer function model was
964043 Memory effects In rocks (review) V. S. Yamshchikov, V. L. Shkuratnik & A. V. Lavrov, Journal of Mining Science, 30(5), 1994(1995), pp 463-473; translated from: Fiziko-Tekhnieheskie Problemy Razrabotki Poleznykh Iskopaemykh, 30(5), 1994, pp 57-69. The ability to store and reproduce information about experienced natural-genetic and technogenic actions is one of the most common qualitative characteristics of rocks and,
tivity distributions F. J. Molz & G. K. Boman, Geophysical Research Letters, 22(18), 1995, pp 2545-2548. Past rescaled range analyses of porosity and hydraulic conductivity (K) distributions have indicated the presence of long-range correlations in the data typical of the related stochastic functions known as fractional Gaussian noise and fractional Brownian motion. New K data analyzed herein lend further support to this notion. Analysis supports the existence of fractal-like K fields similar to those visualized by Ncuman [1990, 1994]. (from Authors)
modelling and measurement