Semi-analytical solution for transient streaming potentials during pumping in a fractured aquifer

It is known that an electric potential gradient, called streaming potential is generated when water flows through a geological medium in subsurface. To quantify the relation between the streaming potential and groundwater flow in a fractured aquifer, the semi-analytical solution for transient streaming potentials during pumping in a fractured aquifer was introduced by coupling the governing equations for streaming potential and groundwater flow in Hankel-Laplace domain. To verify the introduced semi-analytical solution, it matched to the observed streaming potential responses during pumping at an underground research facility whose host rock is fractured granite by optimizing the hydrogeologic properties in the solution, and the optimized hydrogeologic properties were compared to the estimated ones from pumping tests. Results show that the semi-analytical solution can reproduce the streaming potential responses during pumping in a fractured aquifer and be used to reduce the uncertainty in estimation of hydrogeologic properties of a fractured aquifer from a hydraulic test.