Abstract: Directional Semivariograms: Kriging Anisotropy
Without
Anisotropy
Factors
WINGLE, WILLIAM L. and EILEEN P. POETER, Colorado School of Mines, Department of Geology and Geological Engineering
Summary
It is often difficult to fit a model semivariogram to both the
principle-axis and the minor-axes using traditional methods with
anisotropy
ratios. Traditionally, models (possibly nested) are
modified with
anisotropy
factors; these represent the relative
range of the semivariogram for three orthogonal axes. This
technique is restrictive, and this discussion presents a method for
relieving this limitation by defining different semivariogram
models, independently for each axis. These are referred to as
directional semivariograms. The process increases the kriging
processing time by 80% to 200%, but the method offers the modeler
greater flexibility, and simulation or estimation results that are
more representative of the site, because the spatial variation of
the data can be more precisely defined.
AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah