title: In situ measurements of tritium evapotranspiration (³H-ET) flux over grass and soil using the gradient and eddy covariance experimental methods and the FAO-56 model.
abstract: The behaviour of tritium in the environment is linked to the water cycle. We compare three methods of calculating the tritium evapotranspiration flux from grassland cover. The gradient and eddy covariance methods, together with a method based on the theoretical Penmann-Monteith model were tested in a study carried out in 2013 in an environment characterised by high levels of tritium activity. The results show that each of the three methods gave similar results. The various constraints applying to each method are discussed. The results show a tritium evapotranspiration flux of around 15 mBq m(-2) s(-1) in this environment. These results will be used to improve the entry parameters for the general models of tritium transfers in the environment.
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LRC, Laboratoire de Radioécologie de Cherbourg Octeville, Cherbourg-Octeville 50130, France. Electronic address: olivier.connan@irsn.fr.
authors.forename: O
authors.initials: O
authors.lastname: Connan
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LRC, Laboratoire de Radioécologie de Cherbourg Octeville, Cherbourg-Octeville 50130, France.
authors.forename: D
authors.initials: D
authors.lastname: Maro
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LRC, Laboratoire de Radioécologie de Cherbourg Octeville, Cherbourg-Octeville 50130, France.
authors.forename: D
authors.initials: D
authors.lastname: Hébert
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LRC, Laboratoire de Radioécologie de Cherbourg Octeville, Cherbourg-Octeville 50130, France.
authors.forename: L
authors.initials: L
authors.lastname: Solier
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire (IRSN), IPRP-ENV/SESURE/LS3E, Laboratoire de Surveillance et d'Expertise Environnementale par Echantillonnage, Le Vésinet 78116, France.
authors.forename: P
authors.initials: P
authors.lastname: Caldeira Ideas
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SERIS/LRC, Laboratoire de Radioécologie de Cherbourg Octeville, Cherbourg-Octeville 50130, France.
authors.forename: P
authors.initials: P
authors.lastname: Laguionie
authors.affiliation: Canadian Nuclear Safety Commission, Ottawa, Canada.
authors.forename: N
authors.initials: N
authors.lastname: St-Amant
mesh_terms: D065948:Grassland; D008962:Models, Theoretical; D018526:Plant Transpiration; D006109:Poaceae / Q000378:metabolism*; D011834:Radiation Monitoring / Q000379:methods*; D012987:Soil / Q000737:chemistry*; D014316:Tritium / Q000378:metabolism*
chemical_list: D012987:Soil; D014316:Tritium
keywords: Eddy covariance method; Evapotranspiration; Flux; Gradient method; Grass; Tritium