Application of the DEXP method to the streaming potential data

We interpret the self-potential data related to groundwater flow by the depth from extreme points (DEXP) method; a multiscale method in which the data are upward-continued and scaled by a scaling law depend on the structural index. The depth to the water table is estimated from extreme points of the DEXP image without a priori estimate of the hydraulic coupling coefficient. The method is tested with a synthetic model of the water table and applied to a real self-potential dataset near a pumping well. The obtained results agree well with the known information.