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 original ly proposed analytical solutions to the problem and a numerical model have been tested. The analysis showed that the hydraulic parameters determined f rom the test data were correlated, Particularly it was shown that the verti cal hydraulic conductivity and the specific storage could not be determined to an acceptable degree of reliability when based on the originally propos ed analytical solution and on measurements from only the dipole well. Inste ad, an inverse numerical multilayer model was proposed for parameter identi fication using the pressure response data measured not only in the dipole w ell but also in adjacent piezometers, The vertical profiles of horizontal a nd vertical hydraulic conductivities obtained at the site using the single- well dipole method were in accordance with the results from previous invest igations that used other methods.