Single-Well Dipole Flow Tests: Parameter Estimation and Field Testing

The single-well dipole method proposed by Kabala (1993) has been tested at a field site in Denmark representing an alluvial sandy unconfined aquifer. A critical review of the method has been carried out, and both the originally proposed analytical solutions to the problem and a numerical model have been tested. The analysis showed that the hydraulic parameters determined from the test data were correlated. Particularly it was shown that the vertical hydraulic conductivity and the specific storage could not be determined to an acceptable degree of reliability when based on the originally proposed analytical solution and on measurements from only the dipole well. Instead, an inverse numerical multilayer model was proposed for parameter identification using the pressure response data measured not only in the dipole well but also in adjacent piezometers. The vertical profiles of horizontal and vertical hydraulic conductivities obtained at the site using the single-well dipole method were in accordance with the results from previous investigations that used other methods.

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