During floods, submerged vegetation strongly interacts with the flow field, thus determining alterations of depth and velocity. Such interactions are influenced by vegetation density, flexural properties and presence or absence of foliage. In hydraulic modelling, the classical approach to account for vegetation friction is the assignment of a fixed roughness value to specific vegetation structural types (e.g. herbs, shrubs or trees). Although this approach is still widely used in practical applications, it fails to capture fundamental aspects of the vegetation-flow interaction, i.e. the different behavior of plants under different submersion degree or flow velocities. In recent times, more realistic approaches have been proposed. Such methods derived mathematical formulation of the friction factors based on vegetation properties that are measurable from field investigation or remote sensing techniques. These formulations appear to be promising, nevertheless their application is limited to point observations and thus viable only to model hydraulics which are relevant to the measurement period. Conversely, long term landscape evolution simulations require vegetation friction parameterization consistent with vegetation development. The present investigation attempts to fill this gap by proposing a set of measures and techniques to extrapolate long term vegetation friction development associated with vegetation maturation. Such a method could represent a viable solution for riparian landscape evolution models aiming at more accurate representation of vegetation-flow field interaction.