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Main Authors: Abulkhair, Sultan, Dowd, Peter A., Xu, Chaoshui
Format: Preprint
Published: 2022
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Online Access:https://arxiv.org/abs/2210.10461
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author Abulkhair, Sultan
Dowd, Peter A.
Xu, Chaoshui
author_facet Abulkhair, Sultan
Dowd, Peter A.
Xu, Chaoshui
contents One of the most challenging aspects of multivariate geostatistics is dealing with complex relationships between variables. Geostatistical co-simulation and spatial decorrelation methods, commonly used for modelling multiple variables, are ineffective in the presence of multivariate complexities. On the other hand, multi-Gaussian transforms are designed to deal with complex multivariate relationships, such as non-linearity, heteroscedasticity and geological constraints. These methods transform the variables into independent multi-Gaussian factors that can be individually simulated. This study compares the performance of the following multi-Gaussian transforms: rotation based iterative Gaussianisation, projection pursuit multivariate transform and flow transformation. Case studies with bivariate complexities are used to evaluate and compare the realisations of the transformed values. For this purpose, commonly used geostatistical validation metrics are applied, including multivariate normality tests, reproduction of bivariate relationships, and histogram and variogram validation. Based on most of the metrics, all three methods produced results of similar quality. The most obvious difference is the execution speed for forward and back transformation, for which flow transformation is much slower.
format Preprint
id arxiv_https___arxiv_org_abs_2210_10461
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Geostatistics in the presence of multivariate complexities: comparison of multi-Gaussian transforms
Abulkhair, Sultan
Dowd, Peter A.
Xu, Chaoshui
Methodology
Applications
One of the most challenging aspects of multivariate geostatistics is dealing with complex relationships between variables. Geostatistical co-simulation and spatial decorrelation methods, commonly used for modelling multiple variables, are ineffective in the presence of multivariate complexities. On the other hand, multi-Gaussian transforms are designed to deal with complex multivariate relationships, such as non-linearity, heteroscedasticity and geological constraints. These methods transform the variables into independent multi-Gaussian factors that can be individually simulated. This study compares the performance of the following multi-Gaussian transforms: rotation based iterative Gaussianisation, projection pursuit multivariate transform and flow transformation. Case studies with bivariate complexities are used to evaluate and compare the realisations of the transformed values. For this purpose, commonly used geostatistical validation metrics are applied, including multivariate normality tests, reproduction of bivariate relationships, and histogram and variogram validation. Based on most of the metrics, all three methods produced results of similar quality. The most obvious difference is the execution speed for forward and back transformation, for which flow transformation is much slower.
title Geostatistics in the presence of multivariate complexities: comparison of multi-Gaussian transforms
topic Methodology
Applications
url https://arxiv.org/abs/2210.10461