SREL Reprint #1555





The Accuracy of Single-layered and Multi-layered Dynamic Filtration Models for Particulate Interception and Retention in Plant Canopies

John E. Pinder III

Savannah River Ecology Laboratory, Aiken, South Carolina 29801, USA


Models of the form

dA (t)/dt = [ 1 - EXP(-µB(t))] D - ^eA(t)

where A (t) is the radionuclide inventory (Bq m-2) on the vegetation at time t, B (t) is the vegetation biomass (kg dry mass m-2) at t, µ is the absorption coefficient (m2 kg-1), D is the radionuclide deposition rate (Bq m-2 t-1), and Ae, is the effective loss rate constant (t-1) for radionuclide loss from plant surfaces, were used to predict the 238Pu inventories of wheat, soybeans and corn. Data on 238Pu inventories due to deposition were available from several fields near the H-Area nuclear fuel chemical separations facility on the US Department of Energy's Savannah River Site. Estimates of µ and Ae were also obtainedfrom studies near H-Area. Themodelwasgenerallyaccurate. Eighteen of the 2O predicted inventories were within a factor of 2 of the observed mean inventories. Median predicted to observed ratios were1-01, 1-23 and 0-75 for wheat, soybeans and corn, respectively. A multi-layered model composed of separate equations for 1-m height intervals of corn was slightly more accurate with median predicted to observed ratios of 1-17, 1-08 and 1-0l for the 0-l m, 1-2 m and >2 m layers, respectively.

SREL Reprint #1555

Pinder, J.E., III. 1991. The accuracy of single layered and multi layered dynamic filtration models for particulate interception and retention in plant canopies. Journal of Environmental Radioactivity 14:37-53.

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