| Abstract: | The vertical permeability to air of layered materials in the unsaturated zone may be determined from air pressure data obtained at depth during a period when air pressure is changing at land surface. Such data may be obtained by monitoring barometric pressure with a microbarograph or surveying altimeter and simultaneously measuring down-hole pneumatic head differences in specially constructed piezometers. These data, coupled with air-filled porosity data from other sources, may be compared with the results of electric-analog or numerical solution of the one-dimensional diffusion equation to make a trial-and-error determination of the air permeability for each layer. The permeabilities to air may in turn be converted to equivalent hydraulic conductivity values if the materials are well drained, are permeable enough that the Klinkenberg effect is small, and are structurally unaffected by wetting. The method offers potential advantages over present methods to evaluate sites for artificial recharge by spreading; to evaluate ground-water pollution hazards from feedlots, sanitary landfills , and land irrigated with sewage effluent; and to evaluate sites for temporary storage of gas in the unsaturated zone. (Woodard-USGS) |
| Genre: | USGS Numbered Series |
| ProdID: | 6515 |
| Citation Author: | Weeks, Edwin P. |
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| Citation Language: | ENGLISH |
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| Citation Phsyical Description: | 41 p. |
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| Citation Publisher: | U.S. Govt. Print. Off., |
| Citation Series: | Professional Paper |
| Citation Series Code: | PP |
| Citation Series Number: | 1051 |
| Citation Search Results Text: | Field determination of vertical permeability to air in the unsaturated zone; 1978; PP; 1051; Weeks, Edwin P. |
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| Citation Year: | 1978 |
| Type: | citation/reference |
| Text: | Field determination of vertical permeability to air in the unsaturated zone; 1978; PP; 1051; Weeks, Edwin P. |
| URL (THUMBNAIL): | http://pubs.usgs.gov/pp/1051/report-thumb.jpg |
| URL (DOCUMENT): | http://pubs.usgs.gov/pp/1051/report.pdf |
| Date Other: | Sat, 1 Jan 1994 00:00 -0600 |
| Publisher: | U.S. Govt. Print. Off., |
| Superseded by: |
http://pubs.er.usgs.gov/publication/ofr77346
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