Modeling the dynamics of long-term cycling and storage of /sup 137/Cs in forested ecosystems

Conference · Fri Apr 01 04:00:00 EST 1988

OSTI ID:5144836

Van Voris, P; Cowan, C E; Cataldo, D A; Wildung, R E; Shugart, H H

A microcomputer digital simulation model (RADFORET) was developed to predict the long-term (/approximately/250 years) cycling of radiocesium in forested ecosystems using detailed /sup 137/Cs distribution data from two ecosystems. The primary forcing functions for the model were the concentration of/sup 137/Cs in the soil compartment and the rate of forest growth. Parameters were set for controlling the movement of /sup 137/Cs from soil into, and the subsequent cycling within, the biotic compartments of the model for each ecosystem. The amount of the /sup 137/Cs available for uptake from the soil was inversely correlated with the clay content in the soil from each site and was positively correlated with cation exchange capacity (CEC) and soil organic matter. The effect of forest growth as a forcing function in the /sup 137/Cs cycling model was stimulated by coupling the output of a microcomputer digital simulation forest growth sucession model (FORET) to the cycling model. Thus, the radiocesium concentration in each of the seven compartments of the model resulted from both the donor-controlled linear differential equation model of radiocesium concentration in the soil and the dynamics of forest biomass over time. Forecasts of /sup 137/Cs distribution in the donor-controlled model favorably compared with actual /sup 137/Cs distribution in forests at Oak Ridge, Tennessee, and Savannah River, Georgia. This comparsion provided a measure of model validity for additional simulations of projected radiocesium cycling in the forests around the Chernobyl nuclear reactor accident site in the USSR.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA); Virginia Univ., Charlottesville (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 5144836
• Report Number(s): PNL-SA-15721; CONF-880367-5; ON: DE88009487
• Country of Publication: United States
• Language: English

Related Subjects

510300* -- Environment
Terrestrial-- Radioactive Materials Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ALKALI METAL ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CESIUM 137
CESIUM ISOTOPES
ENVIRONMENTAL TRANSPORT
FORCING FUNCTIONS
FORESTS
ISOTOPES
MASS TRANSFER
MATHEMATICAL MODELS
MINERAL CYCLING
NUCLEI
ODD-EVEN NUCLEI
RADIOISOTOPES
RADIONUCLIDE MIGRATION
SOILS
YEARS LIVING RADIOISOTOPES