title: Uncertainty related to input parameters of (137)Cs soil redistribution model for undisturbed fields.
abstract: This study presents an alternative method to empirically establish the effective diffusion coefficient and the convective velocity of (137)Cs in undisturbed soils. This approach offers the possibility to improve the parameterisation and the accuracy of the (137)Cs Diffusion and Migration Model (DMM) used to assess soil erosion magnitudes. The impact of the different input parameters of this radiometric model on the derived-soil redistribution rates has been determined for a Romanian pastureland located in the northwest extremity of the Transylvanian Plain. By fitting the convection-diffusion equation to the available experimental data, the diffusion coefficient and convection velocity of (137)Cs in soil could be determined; 72% of the (137)Cs soil content could be attributed to the (137)Cs fallout originating from Chernobyl. The medium-term net erosion rate obtained with the calculated input parameters reached -6.6 t ha(-1) yr(-1). The model highlights great sensitivity to parameter estimations and the calculated erosion rates for undisturbed landscapes can be highly impacted if the input parameters are not accurately determined from the experimental data set. Upper and lower bounds should be established based on the determined uncertainty budget for the reliable estimates of the derived redistribution rates.
authors.affiliation: Babeş-Bolyai University, Faculty of Environmental Science and Engineering, 30 Fantânele, 400294 Cluj-Napoca, Romania. Electronic address: iurian.andra@ubbcluj.ro.
authors.forename: Andra-Rada
authors.initials: AR
authors.lastname: Iurian
authors.affiliation: Soil and Water Management and Crop Nutrition Laboratory, Joint FAO/IAEA Programme Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, Austria.
authors.forename: Lionel
authors.initials: L
authors.lastname: Mabit
authors.affiliation: Babeş-Bolyai University, Faculty of Environmental Science and Engineering, 30 Fantânele, 400294 Cluj-Napoca, Romania.
authors.forename: Constantin
authors.initials: C
authors.lastname: Cosma
mesh_terms: D002586:Cesium / Q000032:analysis*; D002588:Cesium Radioisotopes / Q000032:analysis; D047852:Chernobyl Nuclear Accident; D004058:Diffusion; D008962:Models, Theoretical; D054043:Nuclear Weapons; D011834:Radiation Monitoring; D011847:Radioactive Fallout / Q000032:analysis*; D012383:Romania; D012989:Soil Pollutants / Q000032:analysis*; D035501:Uncertainty
chemical_list: D002588:Cesium Radioisotopes; D011847:Radioactive Fallout; D012989:Soil Pollutants; D002586:Cesium
keywords: (137)Cs; convection–diffusion equation; diffusion and migration model; erosion rate; radionuclide migration; undisturbed soil