Sensitivity analysis of geologic computer models: A formal procedure based on Latin hypercube sampling
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Mathematical models in which a response variableY is calculated, usually via a computer program, as a function of input variablesX 1 ,X2, ...,Xk are encountered frequently in earth sciences literature. In many cases, uncertainty in the knowledge of the correct values of the input variables exists, leading to uncertainty in the correct value of the response. Sensitivity analysis procedures can be used to identify which input variable uncertainties contribute most to uncertainty in the response variable.
This paper presents the technique of Latin hypercube sampling, a structured, formal sampling process used in the sensitivity analysis procedure. Output resulting from the sample is analyzed using stepwise regression analysis, leading to identification of key input variables. Future data gathering activities can then be done efficiently, focusing on these variables. The technique is applied to a model, developed by Sudicky and Frind, which represents the flow of a contaminant through a porous media.
Key wordssensitivity analysis Latin hypercube sampling stepwise regression computer models
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