This session deals with the use of geophysical methods for the characterization of subsurface properties, states, and processes in a pure hydrological and a contaminant hydrological context. Geophysical methods potentially provide subsurface data with an unprecedented spatial and a high temporal resolution in a non-invasive manner. However, the interpretation of geophysical measurements in a (contaminant) hydrological context is far from straightforward and many challenges still remain. Amongst these, we emphasize the need for improved quantitative use of geophysical measurements in model conceptualization and parameterization, and the need to move hydrogeophysical investigations beyond the column and field scale towards the catchment scale. In particular, we encourage submissions addressing advances in i) the acquisition, inversion and interpretation of geophysical data and other minimally invasive methods in a (contaminant) hydrological context, ii) model-data fusion including new concepts for joint and coupled inversion, and iii) petrophysical understanding linking hydrological and geophysical properties.