Hydrogeophysical Characterization of Aquifers Using Streaming Potentials

We present semi-analytical solutions for transient streaming potentials associated with pumping from unconfined and confined aquifer through a fully-penetrating line sink. Aquifer flow is assumed to occur without fluid leakage from the confining units. The solutions are fitted to field measurements of streaming potentials associated with an aquifer test performed at the Boise Hydrogeophysical Research Site, and at a site located near Montalto Uffugo, in the region of Calabria in Southern Italy. Estimated aquifer parameters compare well to estimates obtained using only hydraulic head data. Our work indicates that, where observation wells are unavailable to provide more direct estimates, streaming potential data collected at land surface may, in principle, be used to provide preliminary estimates of aquifer hydraulic conductivity and specific storage, where the latter is estimated with greater uncertainty than the former. This work is fundamental to hydrogeophysical characterization of flow in aquifers, and therefore, to transport of contaminants in the subsurface.