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An Analysis of Bias in Groundwater Modelling Due to theInterpretation of Site Characterization Data

Published online by Cambridge University Press:  03 September 2012

K. J. Clark ,
T. Ikeda ,
M. D. Impey ,
T. McEwen  and
M. White
K. J. Clark
Affiliation:
QuantiSci Ltd, Chiltern House, 45 Station Rd, Henley-on-Thames, Oxon, RG9 1AT, UK, kclark@quantisci.co.uk
T. Ikeda
Affiliation:
JGC Corporation, Yokohama, Japan.
M. D. Impey
Affiliation:
QuantiSci Ltd, Chiltern House, 45 Station Rd, Henley-on-Thames, Oxon, RG9 1AT, UK, kclark@quantisci.co.uk
T. McEwen
Affiliation:
QuantiSci Ltd, Melton Mowbray, Leics, UK, tmcewen@quantisci.co.uk
M. White
Affiliation:
QuantiSci Ltd, Melton Mowbray, Leics, UK, tmcewen@quantisci.co.uk
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Abstract

Bias is a difference between model and reality. Bias can be introduced atany stage of the modelling process during a site characterisation orperformance assessment programme. It is desirable to understand such bias soas to be able to optimally design and interpret a site characterisationprogramme. The objective of this study was to examine the source and effectof bias due to the assumptions modellers have to make because reality cannotbe fully characterised in the prediction of ground-water fluxes. Awell-defined synthetic “reality” was therefore constructed for this study. Alimited subset of these data were independently interpreted and used tocompute groundwater fluxes across specified boundaries in a cross section.The modelling results were compared to the “true” solutions derived usingthe full dataset. This study clarified and identified the large number ofassumptions and judgements which have to be made when modelling a limitedsite characterisation dataset. It is concluded that bias is introduced ateach modelling stage, and that it is not necessarily detectable by themodellers even if multiple runs with varied parameter values areundertaken.

Information

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 465: Symposium II – Scienfific Basis for Nuclear Waste Management XX , 1996 , 1125
Copyright
Copyright © Materials Research Society 1997

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References

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