Structural sediment connectivity assessment through a geomorphometric approach review of recent applications

Sediment connectivity, defined as the degree to which a system facilitates the transfer of water and sediment through itself by means of coupling relationships between its components, has become a key issue in sediment transfer processes analysis and one of the building blocks of modern geomorphology. The growing availability of high-resolution Digital Elevation Models (DEMs) offers new opportunities for the characterization of sediment connectivity spatial patterns. An index of sediment connectivity, based on DEM derivatives as drainage area, slope, flow length and surface roughness, has been recently developed along with related freeware software tool (SedInConnect). The index aims at depicting spatial connectivity patterns at the catchment scale to support the assessment of the contribution of a given part of the catchment as sediment source and define sediment transfer paths. The increasing interest in the quantitative characterization of the linkages between landscape units and the straightforward applicability of this index led to numerous applications in different contexts. Such works demonstrate that, when carefully applied considering the intrinsic limitations of the geomorphometric approach, the index can rapidly provide a spatial characterization of sediment dynamics, thus improving the understanding geomorphic system behavior and, consequently, hazard and risk assessment. This work presents and discusses the main applications of this sediment connectivity index.