In hydrology and other geosciences, geophysical methods are transforming our ability to see into the complex subsurface and monitor various processes occurring with it. In such applications, robust petrophysical relationships are required to link measured geophysical properties to other physical or chemical properties of interest. This session seeks petrophysical studies in hydrogeophysics and near-surface geophysics, including but not limited to aquifer characterization, critical zone geophysics, geohazard investigation, permafrost study, engineering geophysics, and biogeophysics. In particular, this session looks for petrophysical studies addressing the effects of hydrological and geological processes (e.g., mineral precipitation and dissolution, deformation, infiltration and drainage, weathering, and temperature) on the physical properties of geological materials are welcome. In addition, field applications demonstrating the successful use of novel or established petrophysical relationships are also welcome.