Past Abstract Details

 
 

2009 poster

Using Wavelet Analysis to Investigate Statistical Properties in Hydraulic Conductivity Fields and Hydraulic Head Fields

Dillin, Matt 1 ; Neupauer, Roseanna M 2

1 University of Colorado
2 University of Colorado

Wavelet analysis involves an integral transform of, for example, a hydraulic conductivity field, using a wavelet as the kernel of the transform. A wavelet is a function that is non-zero only over a finite region; therefore the wavelet transform analyzes only a subset of the data set. The wavelet is shifted to analyze different subsets of the data set, and it is scaled to analyze different scales of the data set. We perform wavelet analysis and calculate the local wavelet energy spectrum (LWES), which provides information about dominant length scales at each position in the domain. We generate sets of bounded, one- and two-dimensional, stationary hydraulic conductivity fields with known statistical properties and we run numerical flow simulations, with constant head boundaries, using these fields. We use wavelet analysis to analyze the dominate scales in both the hydraulic conductivity fields and resulting non-stationary head fields, and we explore the relationships between dominant scales in the hydraulic conductivity field and dominant scales in flow. We develop analytical solutions for the LWES to corroborate these relationships.

Farge, M. (1992), Wavelet transforms and their applications to turbulence, Annu. Rev. Fluid Mech., 24, 395-457.

Qi and R. Neupauer, Wavelet analysis of dominant scales of heterogeneous porous media, Water Res. Research, 44, 9.

 

Fig 1. Example analysis of a synthetic one-dimensional stationary hydraulic conductivity field. (a) Stationary random field with an exponential covariance and a dominant length scale of 20 m. (b) Local wavelet energy spectrum identifing dominant scales at each location in the field (c) Global wavelet energy spectrum identifing the average dominant scale for the entire field.

 

 

 

 

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