Estimation of the Variogram Using Kendall's Tau for a Robust Geostatistical Interpolation
Loading...
Authors
Lebrenz, Henning
Bárdossy, András
Author (Corporation)
Publication date
14.01.2017
Typ of student thesis
Course of study
Collections
Type
01A - Journal article
Editors
Editor (Corporation)
Supervisor
Parent work
Journal of Hydrologic Engineering
Special issue
DOI of the original publication
Link
Series
Series number
Volume
Issue / Number
Pages / Duration
Patent number
Publisher / Publishing institution
Place of publication / Event location
Edition
Version
Programming language
Assignee
Practice partner / Client
Abstract
The estimation of an appropriate variogram is a crucial step toward the description of spatial dependence, the geostatistical interpolation of environmental variables, and the subsequent hydrological engineering. The classical variogram in the literature ideally necessitates a normal distribution of the variable and is not robust against outliers within the data. These presumptions are hardly given under empirical conditions and, therefore, a new estimation method is proposed for the variogram. The new method is based on the description of spatial dependence by the robust rank coefficient τ and generalizes the method from the Gaussian to the general case of empirical distributions. The conversion of the robust estimate using a Monte-Carlo simulation and subsequent quantile-quantile transformation with the empirical marginal distribution performs the generalization. Monthly precipitation data from South Africa serve as the variable and were artificially contaminated with outliers. The effects on the variogram and subsequent geostatistical interpolation were investigated for the proposed, classical, and four existing robust variogram models in this comparative study. The investigation revealed that the proposed variogram describes a distinct spatial dependence structure under empirical conditions, which is robust against outliers. The cross validation of the linear estimator demonstrates that the proposed variogram tends to improve the bias and spread of the resulting error distribution, and hence the quality of the geostatistical interpolation.
Keywords
Subject (DDC)
Event
Exhibition start date
Exhibition end date
Conference start date
Conference end date
Date of the last check
ISBN
ISSN
1084-0699
1943-5584
1943-5584
Language
English
Created during FHNW affiliation
Yes
Strategic action fields FHNW
Publication status
Published
Review
Peer review of the complete publication
Open access category
License
Citation
Lebrenz, H., & Bárdossy, A. (2017). Estimation of the Variogram Using Kendall’s Tau for a Robust Geostatistical Interpolation. Journal of Hydrologic Engineering. http://hdl.handle.net/11654/25719