Unraveling the relationship between geomorphodiversity and sediment connectivity in a small alpine catchment

Mountain regions are characterized by a spatial geomorphic heterogeneity that confers on the environment a significant geomorphodiversity. A methodology based on a different scale/spatial/resolution approach is proposed to evaluate the relationship existing among geomorphodiversity, geomorphological processes. and sediment connectivity. Starting from the geomorphological mapping of the Veglia Devero Natural Park (Lepontine Alps), indexes of fragmentation (IFrm) and geomorphodiversity (IGmf) were computed. The results were used to select a meaningful sub-area (Buscagna stream catchment) for calculating the index of connectivity (IC). The relationships among these three indexes are discussed, using a semi-quantitative approach including descriptive statistics (i.e., box plot) and analysis of the different geomorphoconnectivity sectors, testifying to the role of geomorphic processes in regulating sediment fluxes and, consequently, controlling landscape units. IGmf turned out to be more conservative than IFrm and more management-oriented for protected areas, while IC was confirmed to be particularly suitable to characterize connectivity in small mountain catchments featuring different geomorphic processes and a complex topography. This study suggests that coupling the sediment connectivity with the geomorphology and geomorphodiversity of a given area represents a quite novel approach that could be usefully applied in the framework of protected areas to investigate also biodiversity patterns and consequently environmental evolution in space and time.