Expert elicitation for the variogram

Phuong N. Truong; Gerard B.M. Heuvelink; John Paul Gosling

Expert elicitation for the variogram

Phuong N. Truong, Gerard B.M. Heuvelink, John Paul Gosling

Research output: Contribution to conference › Paper › peer-review

Abstract

The variogram is the keystone of Kriging. Much research has been devoted to modelling the variogram from structural analysis of observations. However, there are many instances when the variogram is needed and there are no observations to base on. This can be due to budget constraints, physical or temporal obstacles, or a demand for a priori variogram in Bayesian geostatistics and spatial sampling design. Using expert knowledge that is elicited with a formal statistical expert elicitation procedure is suggested. In this study, we designed a protocol for a wellstructured elicitation procedure to elicit the variogram from expert knowledge. The protocol has two main stages: elicitation of the marginal probability distribution and elicitation of the variogram. We built a web-based tool to facilitate the procedure. A case study was carried out to quantify spatial accuracy of a legacy map of the volumetric soil water content at field capacity. Expert elicitation returns a variogram that has a Matern model shape with nugget = 0.45, partial sill = 54.57, range = 25410 meters and kappa = 0.40. The results show that the online elicitation tool satisfactorily captured expert opinion although, currently, it is only a prototype that needs to be further developed.

Original language	English
Pages	251-256
Number of pages	6
Publication status	Published - 1 Jan 2012
Externally published	Yes
Event	10th International Symposium on Spatial Accuracy Assessment in Natural Resources and Environmental Sciences 2012 - Florianopolis, Brazil Duration: 10 Jul 2012 → 13 Jul 2012 Conference number: 10 http://spatial-accuracy.org/Accuracy2012

Conference

Conference	10th International Symposium on Spatial Accuracy Assessment in Natural Resources and Environmental Sciences 2012
Abbreviated title	Accuracy 2012
Country/Territory	Brazil
City	Florianopolis
Period	10/07/12 → 13/07/12
Internet address	http://spatial-accuracy.org/Accuracy2012

Keywords

Expert knowledge
Soil property map
Spatial variability
Uncertainty quantification
Vanogram

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http://spatial-accuracy.org/system/files/TruongAccuracy2012.pdf

Cite this

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title = "Expert elicitation for the variogram",

abstract = "The variogram is the keystone of Kriging. Much research has been devoted to modelling the variogram from structural analysis of observations. However, there are many instances when the variogram is needed and there are no observations to base on. This can be due to budget constraints, physical or temporal obstacles, or a demand for a priori variogram in Bayesian geostatistics and spatial sampling design. Using expert knowledge that is elicited with a formal statistical expert elicitation procedure is suggested. In this study, we designed a protocol for a wellstructured elicitation procedure to elicit the variogram from expert knowledge. The protocol has two main stages: elicitation of the marginal probability distribution and elicitation of the variogram. We built a web-based tool to facilitate the procedure. A case study was carried out to quantify spatial accuracy of a legacy map of the volumetric soil water content at field capacity. Expert elicitation returns a variogram that has a Matern model shape with nugget = 0.45, partial sill = 54.57, range = 25410 meters and kappa = 0.40. The results show that the online elicitation tool satisfactorily captured expert opinion although, currently, it is only a prototype that needs to be further developed.",

keywords = "Expert knowledge, Soil property map, Spatial variability, Uncertainty quantification, Vanogram",

author = "Truong, {Phuong N.} and Heuvelink, {Gerard B.M.} and Gosling, {John Paul}",

year = "2012",

month = jan,

day = "1",

language = "English",

pages = "251--256",

note = "10th International Symposium on Spatial Accuracy Assessment in Natural Resources and Environmental Sciences 2012, Accuracy 2012 ; Conference date: 10-07-2012 Through 13-07-2012",

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TY - CONF

T1 - Expert elicitation for the variogram

AU - Truong, Phuong N.

AU - Heuvelink, Gerard B.M.

AU - Gosling, John Paul

N1 - Conference code: 10

PY - 2012/1/1

Y1 - 2012/1/1

N2 - The variogram is the keystone of Kriging. Much research has been devoted to modelling the variogram from structural analysis of observations. However, there are many instances when the variogram is needed and there are no observations to base on. This can be due to budget constraints, physical or temporal obstacles, or a demand for a priori variogram in Bayesian geostatistics and spatial sampling design. Using expert knowledge that is elicited with a formal statistical expert elicitation procedure is suggested. In this study, we designed a protocol for a wellstructured elicitation procedure to elicit the variogram from expert knowledge. The protocol has two main stages: elicitation of the marginal probability distribution and elicitation of the variogram. We built a web-based tool to facilitate the procedure. A case study was carried out to quantify spatial accuracy of a legacy map of the volumetric soil water content at field capacity. Expert elicitation returns a variogram that has a Matern model shape with nugget = 0.45, partial sill = 54.57, range = 25410 meters and kappa = 0.40. The results show that the online elicitation tool satisfactorily captured expert opinion although, currently, it is only a prototype that needs to be further developed.

AB - The variogram is the keystone of Kriging. Much research has been devoted to modelling the variogram from structural analysis of observations. However, there are many instances when the variogram is needed and there are no observations to base on. This can be due to budget constraints, physical or temporal obstacles, or a demand for a priori variogram in Bayesian geostatistics and spatial sampling design. Using expert knowledge that is elicited with a formal statistical expert elicitation procedure is suggested. In this study, we designed a protocol for a wellstructured elicitation procedure to elicit the variogram from expert knowledge. The protocol has two main stages: elicitation of the marginal probability distribution and elicitation of the variogram. We built a web-based tool to facilitate the procedure. A case study was carried out to quantify spatial accuracy of a legacy map of the volumetric soil water content at field capacity. Expert elicitation returns a variogram that has a Matern model shape with nugget = 0.45, partial sill = 54.57, range = 25410 meters and kappa = 0.40. The results show that the online elicitation tool satisfactorily captured expert opinion although, currently, it is only a prototype that needs to be further developed.

KW - Expert knowledge

KW - Soil property map

KW - Spatial variability

KW - Uncertainty quantification

KW - Vanogram

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M3 - Paper

AN - SCOPUS:84975686813

SP - 251

EP - 256

T2 - 10th International Symposium on Spatial Accuracy Assessment in Natural Resources and Environmental Sciences 2012

Y2 - 10 July 2012 through 13 July 2012

ER -

Expert elicitation for the variogram

Abstract

Conference

Keywords

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