Empirical Bayes regionalization techniques for estimation in ground water models

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6797965

Butcher, J B

Groundwater contaminant transport risk analysis requires the estimation of parameters exhibiting strong spatial correlation, such as the hydraulic conductivity tensor. Analysis must often be undertaken under conditions of limited data. The estimation process may be strengthened, and the estimation risk reduced by utilizing regional data. The regionalization process is formalized through Parametric empirical Bayes analysis. New Empirical Bayes solutions are proposed for several cases involving spatial stochastic processes. These determine iterative solutions through an Expectation-Maximization algorithm. Tests on synthetically generated data indicate that the Empirical Bayes estimators show performance superior to simple regression and kriging estimators on an average squared prediction error criterion. The methods are applied to the problem of predicting transmissivities in East-Central Illinois glacial drift. Prospects for other useful applications appear good. However, synthetic data test indicate that the Empirical Bayes estimators will have a tendency to underestimate the total process variance because the uncertainty in determining the prior parameter values is ignored.

• Research Organization: Duke Univ., Durham, NC (USA)
• OSTI ID: 6797965
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540320* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
ALGORITHMS
CONTAMINATION
ENVIRONMENTAL TRANSPORT
FORECASTING
GROUND WATER
HYDRAULIC CONDUCTIVITY
HYDROGEN COMPOUNDS
MASS TRANSFER
MATHEMATICAL LOGIC
MATHEMATICAL MODELS
OXYGEN COMPOUNDS
POLLUTION
RISK ASSESSMENT
STOCHASTIC PROCESSES
WATER
WATER POLLUTION