Model simulations of the fate of 14C added to a Canadian shield lake |
| |
Institution: | 1. University of Rouen-Normandie, UMR CNRS 6143 M2C, 76821 Mont Saint Aignan, France;2. Institut de Radioprotection et de Sureté Nucléaire (IRSN), PSE-ENV, SRTE/LRTA, SAME/LMRE, BP 3, 13115 Saint-Paul-lez-Durance, France;3. University of Tours, EA 6293, laboratoire GéHCO, 37200 Tours, France;4. University of Nîmes, EA7352 CHROME, Laboratoire GIS, 30035 Nîmes, France;5. Sorbonne Université, UMR CNRS 7619 METIS, 75252 Paris, France;1. Environmental Molecular Sciences Laboratory, Richland, WA 99354, United States;2. Algoma University, Sault Ste. Marie, Ontario P6A 2G4, Canada;3. Washington State University, Pullman, WA 99164, United States |
| |
Abstract: | Carbon-14 was added to the epilimnion of a small Canadian Shield lake to investigate primary production and carbon dynamics. The nature of the spike and subsequent monitoring allowed the investigation of both short-term and longer-term processes relevant to evaluating impacts of accidental and routine releases and of solid waste disposal. Data from this experiment were used in the BIOMOVS II program as a validation test for modelling the fate of the 14C added to the lake. Four models were used: (1) a simple probabilistic mass balance model of a lake; (2) a relatively complex deterministic model; (3) a complex deterministic model; and (4) a more complex probabilistic model. Endpoints were 14C concentrations in water, sediment and lake whitefish over a thirteen year period. Each model produced reasonable predictions when compared to the range of the observed data and when uncertainty in model predictions is taken into consideration. The simple lake model did not account for internal recycling of 14C and, in this respect, its predictions were not as realistic as those of the more complex models for concentrations in water. However, the simple model predictions for the 14C inventory remaining in lake sediment were closest to the observed values. Overall, the more complex probabilistic model was the most accurate in simulating 14C concentrations in water and in whitefish but it overestimated 14C retention in the lake sediments, as did the other complex models. Choice of parameter values for transfer rate to sediment and gaseous evasion are important in influencing model predictions. Although predicted concentrations of 14C in fish of dynamic models were more accurate than those using equilibrium bioconcentration factors typically used in assessments, large variability in observed 14C concentrations in whitefish emphasizes the need for a better understanding of the important processes that influence these contaminant concentrations. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|