Evaluating vertical variability analysis (VVA) for estimating the hydraulic conductivity, specific yield, and transmissivity of four simulated geologic configurations
- Wright Water Engineers, Inc., Denver, CO (United States)
- Colorado School of Mines, Golden, CO (United States)
Aquifer systems derived from fluvial, eolian, glacial, or mass movement processes may have considerable vertical and areal variability in saturated thickness, hydraulic conductivity, specific yield, and bed thickness. Frequently, hydraulic data from aquifer tests are not readily available, whereas lithologic and grain-size information from drillers' logs is generally abundant. Therefore, the vertical variability method was devised to evaluate the aquifer properties for individual lithologic units based on drillers' information. These estimates provide vital information about aquifer characterization and are useful for hydraulic analysis and computer modeling. The purpose of this study was to evaluate the VVA for estimating the hydraulic conductivity, specific yield, and transmissivity of four simulated geological configurations. The objectives were to: (1) test the validity of VVA using the method of moments and the 0.5 criterion for relative center of gravity (RCOG); and (2) conduct a sensitivity analysis of material parameters relative to the RCOG. Results show that the 0.5 criterion for RCOG is valid only on a case-by-case basis depending primarily on the geometry of the geologic deposits, and secondarily on the thickness of individual geologic units. Sensitivity analyses reveal that the parameters of hydraulic conductivity and transmissivity are insensitive to changes in RCOG to plus or minus two to three orders of magnitude. Additional results indicate that the variance of RCOG for eolian, glacial, and incomplete two-cycle fluvial deposits is minimal as compared to the those for single and multiple fluvial cycles.
- OSTI ID:
- 5687776
- Report Number(s):
- CONF-921058--
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Journal Name: Geological Society of America, Abstracts with Programs; (United States) Vol. 24:7; ISSN GAAPBC; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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