Time-Series Analysis for Determining Vertical Air Permeability in Unsaturated Zones
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 125, Issue 1
Abstract
The air pressure in the unsaturated subsurface changes dynamically as the barometric pressure varies with time. Depending on the material properties and boundary conditions, the intensity of the correlation between the atmospheric and subsurface pressures may be evidenced in two persistent patterns: (1) The amplitude attenuation; and (2) the phase lag for the principal modes, such as the diurnal, semidiurnal, and 8-h tides. The amplitude attenuation and the phase lag generally depend on properties that can be classified into two categories: (1) The barometric pressure parameters, such as the apparent pressure amplitudes and frequencies controlled by the atmospheric tides and others; and (2) the material properties of porous media, such as the air viscosity, air-filled porosity, and permeability. Based on the principle of superposition and a Fourier time-series analysis, an analytical solution for predicting the subsurface air pressure variation caused by the atmospheric pressure fluctuation is presented. The air permeability (or pneumatic diffusivity) can be quantitatively determined by using the calculated amplitude attenuations (or phase lags) and the appropriate analytical relations among the parameters of the atmosphere and the porous medium. An analysis using the field data shows that the Fourier time-series analysis may provide a potentially reliable and simple method for predicting the subsurface barometric pressure variation and for determining the air permeability of unsaturated zones.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Baehr, A. L., Hoag, G. E., and Marley, M. C. ( 1989). “Removing volatile contaminants from the unsaturated zone by inducing advective air-phase transport.” J. Contam. Hydro., 4, 1–26.
2.
Baehr, A. L., and Hult, M. F. ( 1991). “Evaluation of unsaturated zone air permeability through pneumatic tests.” Water Resour. Res., 27, 2605– 2617.
3.
Buckingham, E. ( 1904). “Contributions to our knowledge of aeration of soils.” Bull. 25, Soils Bureau, U.S. Department of Agriculture, Washington, D.C.
4.
Carslaw, H. S., and Jaeger, J. C. ( 1959). Conduction of heat in solids. Oxford University Press, New York.
5.
Chapman, S., and Lindzen, R. S. ( 1970). Atmospheric tides, thermal and gravitational . Gordon & Breach, New York, 200.
6.
Falta, R. W., Pruess, K., Javandel, I., and Witherspoon, P. A. ( 1992a). “Numerical modeling of steam injection for the removal of nonaqueous phase liquids from the subsurface, 1, numerical formulation.” Water Resour. Res., 28, 433–449.
7.
Falta, R. W., Pruess, K., Javandel, I., and Witherspoon, P. A. ( 1992b). “Numerical modeling of steam injection for the removal of nonaqueous phase liquids from the subsurface, 2, code validation and application.” Water Resour. Res., 28, 451–465.
8.
Ge, S., and Liao, M. ( 1996). “An analytical solution for airflow to inlet wells vapor extraction systems under leaky conditions.” Water Resour. Res., 32, 743–748.
9.
Hsieh, P. A., Bredehoeft, J. D., and Farr, J. M. ( 1987). “Determination of aquifer transmissivity from earth tide analysis.” Water Resour. Res., 23, 1824–1832.
10.
Hsieh, P. A., and Neuman, S. P. ( 1985). “Field determination of the three-dimensional hydraulic conductivity tensor of anisotropic media 1 theory.” Water Resour. Res., 21, 1655–1665.
11.
Hsieh, P. A., Neuman, S. P., Stiles, G. K., and Simposon, E. S. ( 1985). “Field determination of the three-dimensional hydraulic conductivity tensor of anisotropic media 2 application to fractured rocks.” Water Resour. Res., 21, 1667–1676.
12.
Katz, D. L., et al., eds. ( 1959). Handbook of natural gas engineering . McGraw-Hill, New York, 802.
13.
Massmann, J. W. (1989). “Applying groundwater flow models in vapor extraction system design.”J. Envir. Engrg., ASCE, 115, 129–149.
14.
Mathews, J., and Walker, R. L. ( 1964). Mathematical methods of physics, 2nd Ed., 510.
15.
Rojstaczer, S. ( 1988). “Determination of fluid flow properties from the response of water levels in wells to atmospheric loading.” Water Resour. Res., 24, 1927–1938.
16.
Rojstaczer, S., and Tunks, J. ( 1995). “Field-based determination of air diffusivity using soil air and atmospheric pressure time series.” Water Resour. Res., 31, 3337–3343.
17.
Rousseau, J. P., Kurzmack, M., and Greengard, A. ( 1994). “Results of prototype borehole instrumentation at the hydrologic research facility, area 25, NTS.” Proc., 4th Int. Conf. on High-Level Nuclear Waste Mgmt., ASCE, New York, 2764–2772.
18.
Shan, C. ( 1995). “Analytical solutions for determining vertical air permeability in unsaturated soils.” Water Resour. Res., 31, 2193–2200.
19.
Shan, C., Falta, R. W., and Javandel, I. ( 1992). “Analytical solutions for steady state gas flow to a soil vapor extraction well.” Water Resour. Res., 28, 1105–1120.
20.
Snoeberger, D. F., Baker, J., and Morris, J. C. ( 1973). “Measurements and correlation analysis for nuclear chimney permeability.” Rep. No. UCID-16302, Lawrence Livermore Laboratory, Livermore, Calif.
21.
Snoeberger, D. F., Morris, J. C., and Morris, G. A. ( 1971). “Field measurement of permeabilities in NTS area 9.” Rep. No. UCID-15895, Lawrence Radiation Laboratory, Livermore, Calif.
22.
Stallman, R. W. ( 1967). “Flow in the zone of aeration.” Adv. Hydrosci., 4, 151–195.
23.
Stallman, R. W., and Weeks, E. P. ( 1969). “The use of atmospherically induced gas-pressure fluctuations for computing hydraulic conductivity of the unsaturated zone.” Abs., Geol. Soc. Am. Programs, Part 7, 213.
24.
Stephens, D. B. ( 1995). Vadose zone hydrology. Lewis, Boca Raton, Fla., 339.
25.
Weeks, E. P. ( 1978). “Field determination of vertical permeability to air in the unsaturated zone.” Profl. Paper 1051, U.S. Geological Survey, Lakewood, Colo.
26.
Weeks, E. P. ( 1979). “Barometric fluctuations in wells tapping deep unconfined aquifers.” Water Resour. Res., 15, 1167–1176.
27.
Weeks, E. P. ( 1991). “Does the wind blow through Yucca Mountain?” Proc., Workshop V: Flow and Transport through Unsaturated Fractured Rock—Related to High-Level Radioactive Waste Disposal, Rep. No. NUREG/CP-0040, U.S. Nuclear Regulatory Commission, White Flint, Md., 43–53.
Information & Authors
Information
Published In
History
Received: Sep 5, 1997
Published online: Jan 1, 1999
Published in print: Jan 1999
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.