Flow, transport and deformation in porous media are highly coupled processes that strongly depend on the non-linear interplay between physical, chemical and biological phenomena. According to the current state of the art, the analysis of these processes is mostly carried out on a variety of characteristic spatial and temporal scales that are determined by the geometry, structure and heterogeneity of the porous media. However, it is increasingly being recognised that the relevant overall functioning of porous-media systems is dictated by the character, geometry and dynamics of various types of fluid-fluid and fluid-solid interfaces that occur not only on the characteristic scales but most notably on smaller scales. For this reason, many available model concepts do not adequately capture and predict the actual system behaviour. Examples for this lack of predictive ability include the extended Darcy’s law for multi-phase flow, current models for evaporation from porous media, and existing models for fracture/damage propagation in porous media.