Field study of dispersion in a heterogeneous aquifer. 3. Geostatistical analysis of hydraulic conductivity
- Massachusetts Inst. of Technology, Cambridge (United States)
- Tennessee Valley Authority, Norris (United States)
Observations of the spatial variability of hydraulic conductivity at a tracer test site, located at Columbus Air Force Base in Mississippi, are presented. Direct measurements of hydraulic conductivity of the heterogeneous alluvial aquifer at the site were made using borehole flowmeter logging, slug tests, and a laboratory permeameter to test undisturbed soil cores. Indirect methods estimating hydraulic conductivity were also evaluated, including soil grain size analyses, surface geophysical surveys, and mapping of sediment facies. The spatial covariance of the 2,187 hydraulic conductivity values obtained with the borehole flowmeter method was examined. The log hydraulic conductivity variance ([sigma][sub 1n K][sup 2]) and the horizontal and vertical correlation scales ([lambda][sub h] and [lambda][sub [upsilon]]) of 4.5, 12.8 m, and 1.6 m, respectively, were estimated assuming second-order stationarity of the conductivity field. The covariance parameters are uncertain with bounding values that are 24-76% above or below the estimate. Covariance parameters estimated with more limited nonflowmeter data were within the same magnitude as those obtained using the extensive flowmeter data, suggesting that data from a variety of methods may be used to provide approximate values of the autocovariance parameters. Nonstationarity of the 1n K field was examined by removing three-dimensional polynomial trend surfaces and calculating variograms of the residuals. Significantly lower estimates for [sigma][sub 1n K][sup 2], [lambda][sub h] and [lambda][sub [upsilon]] of 2.7, 4.8 m, and 0.8 m, respectively, were obtained from the third-order log conductivity residuals. After trend removal, the bounding parameter values differ 15-44% from the estimated values. 40 refs., 16 figs., 4 tabs.
- OSTI ID:
- 6793262
- Journal Information:
- Water Resources Research; (United States), Vol. 28:12; ISSN 0043-1397
- Country of Publication:
- United States
- Language:
- English
Similar Records
Theoretical analysis of non‐
Large-scale natural-gradient tracer test in sand and gravel, Cape Cod, Massachusetts 3. Hydraulic conductivity variability and calculated macrodispersivities
Related Subjects
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
AQUIFERS
HYDRAULIC CONDUCTIVITY
BOREHOLES
HYDROLOGY
MATHEMATICAL MODELS
MISSISSIPPI
CAVITIES
DEVELOPED COUNTRIES
NORTH AMERICA
USA
540250* - Environment
Terrestrial- Site Resource & Use Studies- (1990-)
990200 - Mathematics & Computers