Laboratory investigation of a method for determining in situ saturated hydraulic conductivity

A study was conducted to determine the applicability of a method for determining in situ saturated hydraulic conductivity in porous media. This method requires an accurate measurement of the horizontal port water speed through a section of a borehole packed with a porous material of known hydraulic conductivity. Analytical expressions describing the theoretical basis for the method were investigated, as was the sensitivity of these expressions to varied parameters; Experiments were designed and performed in an attempt to determine if the theory could be successfully applied in a laboratory setting. These experiments were conducted in a large flowchamber which simulates a confined, homogeneous and isotropic aquifer, and which allows for precise control of aquifer pore water velocity. Two techniques were examined. The first technique involves measuring the advective component of a heat pulse generated within the borehole porous medium. The second technique involves determining the dilution rate of an electrolytic tracer introduced into the borehole porous medium. For each technique, experimental instruments were designed and constructed, or existing instruments were modified. Theoretical considerations and analytical expressions justifying each technique were developed and investigated