Page 348 - gas transport in porous media

349
Chapter 21: Gas Transport Issues in Landmine Detection
which will significantly influence the near surface soil water and heat balance, or
freezing conditions due to a limitation in the equation of state. In order to avoid
freezing conditions, the air weather temperature was constrained to a minimum
◦
of 12 C.
This effort provides evidence that the T2TNT model can be used to estimate field
conditions for trace chemical detection of buried landmines by comparison to total
soil concentration data. Point sampling and chemical analysis of field soil residue
data were adequately represented by the T2TNT model within the constraints of
several factors: analytical detection limits, 1-D representation of a 3-D field data
set, homogeneous model representation of heterogeneous soil properties, minimum
temperature constraints of the model, and a bare soil representation of a low grass
field.
With careful consideration of these factors, the T2TNT model can be used
to evaluate combinations of weather, soil, and landmine flux to evaluate opti-
mum conditions for use of trace chemical detection technology. This is supported
by recent analysis by the US Government, which determined that methods for
detecting the chemical components of explosives found in landmines and tech-
niques for modeling the environmental effects on various mine sensors needs
priority research (MacDonald et al., 2003). Cooperative efforts between model
improvements, scenario analyses and feedback from field demining campaigns
will further improve the utility of trace chemical detection technology for buried
landmines.

REFERENCES
Hewitt, A.D., Jenkins, T.F., and Ranney, T.A. 2001, Field Gas Chromatography/Thermionic Detector
System for On-Site Determination of Explosives in Soils. US Army Corps of Engineers, Engineer
Research and Development Center, Cold Regions Research and Engineering Laboratory. ERDC/CRREL
TR-01–9. May 2001.
Jenkins, T.F., Walsh, M.E., Miyares, P.H., Kopczynski, J., Ranney, T., George, V., Pennington, J., and
Berry, T., 2000, Analysis of Explosives-Related Chemical Signatures in Soil Samples Collected Near
Buried Landmines. U.S.Army Corps of Engineers, Engineer Research and Development Center, Report
ERDC TR-00–5. August 2000.
Jury, W.A., Spencer, W.F., and Farmer, W.J., 1983, Behavior Assessment Model for Trace Organics in
Soil: I. Model Description. J. Environ. Qual., 12, 558–564.
Jury, W.A., Farmer, W.J., and Spencer, W.F., 1984a, Behavior assessment model for trace organics in soil:
II. Chemical classification and parameter sensitivity. J. Environ. Qual., 13, 567–572.
Jury, W.A., Spencer, W.F., and Farmer, W.J., 1984b, Behavior assessment model for trace organics in soil:
III. Application of screening model. J. Environ. Qual., 13, 573–579.
Jury, W.A., Spencer, W.F., and Farmer, W.J., 1984c, Behavior assessment model for trace organics in soil:
IV. Review of experimental evidence. J. Environ. Qual., 13, 580–586.
Jury, W.A., Russo, D., Streile, G., and Abd, H., 1990, Evaluation of volatilization by organic chemicals
residing below the surface. Water Resour. Res., 26, 13–20, January 1990.
MacDonald, J., Lockwood, J.R., McFee, J., Altshuler, T., Broach, T., Lawrence Carin, Russell Harnon,
Carey Rappaport, W. Scott and R. Weaver, 2003. Alternatives for Landmine Detection. RAND Science