Modelling of radon-222 as a proxy for vapour phase transport in the unsaturated zone

D A Gibbons, R M Kalin, H Johnston

Research output: Chapter in Book/Report/Conference proceedingConference contribution book


This study uses naturally occurring Rn-222 as a tracer in the unsaturated zone to better understand volatile organic compounds (VOC) release, transport and interaction. Using the STELLA Research software package, a two-dimensional model of Rn-222 transport and generation in the unsaturated zone was produced. The model was validated using a laboratory facility comprising of a 2 x 1 x 0.2 m layered chamber. In these experiments transport by diffusion is measured for a homogeneous column of material. The model described the Rn-222 concentrations satisfactorily for both simple and complex experiments. Sensitivity analysis and simulated results demonstrate the importance of moisture content in the transport of Rn-222. The simulations show excellent comparison with experimental data and provide good estimation of Rn-222 activity and VOC transport in the unsaturated zone.
Original languageEnglish
Title of host publicationCalibration and reliability in groundwater modelling
Subtitle of host publicationcoping with uncertainty
EditorsF. Stauffer, W. Kinzelbach, K. Kovar, E. Hoehn
Place of PublicationWallingford
Number of pages6
Publication statusPublished - 2000
EventModelCARE 1999 Conference - Zurich, Switzerland
Duration: 1 Sep 19991 Sep 1999

Publication series

NameIAHS Publication
PublisherInternational Association of Hydrological Sciences
ISSN (Print)0144-7815


ConferenceModelCARE 1999 Conference


  • modelling
  • radon-222
  • proxy
  • vapour phase transport
  • unsaturated zone

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