Rheological stratification of high-concentration liquid-granular flows Michele Larcher CUDAM - Department of Civil and Environmental Engineering, University of Trento firstname.lastname@example.org High concentrated uniform granular flows with water as interstitial fluid are analysed, drawing the attention to the relevance of the condition of flow in equilibrium with the bed. Four different flow regimes have been observed: (a) loose bed, immature debris flow; (b) loose bed, mature debris flow; (c) loose bed, plug debris flow; (d) rigid bed debris flow. The present work presents detailed experimental measurements resorting to a novel recirculatory flume set-up, in combination with recently developed Voronoļ imaging methods, used to obtain a detailed characterisation of the local flow kinematics and of granular concentration, as seen through the flume sidewall. Looking at the profiles of the variables of interest in the stress formation (velocity, fluctuation energy, and solid concentration), it is observed that they change enormously from cases with and without equilibrium. The analysis here proposed stepped out from the possibility to lead on experimental assessments of the kinetic theories in any position inside the flow domain. The results allowed to build a picture of the rheological distribution that is rather simple: throughout the flow depth there are layers that are collisionally dominated, whereas the complementary domains are essentially frictional.