ISSN:
1745-6584
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Energy, Environment Protection, Nuclear Power Engineering
,
Geosciences
Notes:
In situ estimates of advective and dispersive properties of ground-water flow systems are essential for the adequate prediction of solute flow. Field tracer tests provide the best estimates of these properties; however, this approach is often precluded by the expense and time involved. Various laboratory techniques have been developed to circumvent these problems and provide convenient estimates of hydraulic conductivity and dispersivity. Although these techniques are used extensively in hydrogeological investigations, very few attempts have been made to compare their estimates with field values.A detailed investigation was performed on an unconfined sand aquifer using a combination of routine laboratory techniques and an innovative field tracer test. The extensive data set provided a unique opportunity to compare field results with those obtained by a variety of laboratory techniques.The hydraulic conductivity results from two different methods of grain-size analysis (Hazen, 1893; and Masch and Denny, 1966) were observed to be quite well correlated, although their absolute values did not correspond with the hydraulic conductivities determined from the tracer test. However, contrary to previous studies, the results from grain-size analysis were the same order of magnitude as the in situ values. In addition, the two grain-size methods appear to provide upper and lower boundaries within which lie the hydraulic conductivity estimates determined from the tracer test. Thus, grain-size analysis of moderately to well sorted sands may provide reasonable and convenient approximations of hydraulic conductivities of the aquifer.No correlation was observed between field tracer test longitudinal dispersivity values and those determined from laboratory column tracer tests. The latter, however, differed by only an order of magnitude from the in situ point measurements, a difference which is considerably smaller than has been previously reported. This is largely attributed to the accuracy of the sampling methods used in the tracer tests.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1745-6584.1987.tb02136.x
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