Applying Geophysical Methods to Estimate Hydraulic Parameters for the Saturated Zones in Lolo Creek, Montana

The relationship between aquifer hydraulic conductivity and electrical resistivity has been studied, both in laboratories and on field scale at different locations using different approaches. This relationship lacks dimensionality, therefore, most case studies produced empirical and site specific formulations. The Lolo creek area in Montana undergoes a broad geological and hydrogeological investigation to evaluate groundwater/surface-water interactions. Resistivity measurements taken in the vicinity of Lolo creek and HW 93 used to delineate the saturated zones. Drilling cuts and rock samples from newly drilled wells in the area - provide opportunity to perform successive resistivity measurements at different water salinity, as well as petro-physical and hydraulic measurements. Our goals are a) to use resistivity measurements to extrapolate hydraulic parameters in zones with no wells, and b) to compare between calculated and measured hydraulic conductivities to construct a robust model that could be used at different locations.