Abstract
An advection-diffusion equation with time and space dependent random coefficients is derived as a model for the plutonium concentration changes in the surface soil around the Rocky Flats Plant northwest of Denver, Colorado. The equation is used to fit a set of temporal-spatial data sampled annually over a 23 year period from 71 sites around the plant. The coefficients of the advection-diffusion equation are derived from the estimated covariance function of the observed random field using a combination of maximum likelihood and quasi-likelihood techniques. Goodness-of-fit of the model to the data is also assessed. Finally we interpret the model in terms of the advection-diffusion mechanism.
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Mohapl, J. A Stochastic Advection-Diffusion Model for the Rocky Flats Soil Plutonium Data. Annals of the Institute of Statistical Mathematics 52, 84–107 (2000). https://doi.org/10.1023/A:1004137016101
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DOI: https://doi.org/10.1023/A:1004137016101