The hydromorphological way to the evaluation of e-flows

River hydromorphological processes have been severely altered by human pressures, with subsequent impacts in river ecological status. Such impacts could be mitigated implementing functional water (and sediment) flows regimes, i.e. environmental flows (E-flows). E-flows are determined by various methods and approaches, and their range in time reflects the degree of knowledge achieved in the field of river sciences, and in particular in the domain of ecohydro- geomorphology. A first paradigm shift in the late 90’s recognized that not only the magnitude but also all the components of flow regime are crucial for ecosystems functioning. This means that minimum flow strategy cannot be effective measure to restore some ecological processes. Recently, that paradigm was better reformulated to stress the necessity of considering sediment dynamics in the specification of environmental flows. Hydrological and geomorphological processes are indeed coupled over a wide range of spatial and temporal scales and any change in one affects the other, resulting in alteration of riverine habitats. In spite of those evident linkages in space and time, current restoration approaches, such as minimum flows (e.g. DMV in Italy), typically focus only on changes on hydrological regime as a means promoting ecological enhancements. Neglecting the multispectral nature of flows and their interaction with sediment transport in shaping riverine habitats is likely to results not only in minor or no enhancements in the ecology, but may also increase the costs of water use. Therefore, a multi scale, process based diagnostic and prognostic framework has to be adopted in order to diagnose the mechanisms of alteration and the possible rehabilitation actions. Here we present, in particular, a methodology for the estimation of environmental flows, based on the implementation of such an analysis.