The morpho-textural signature of large bedforms in ephemeral gravel-bed channels of various planforms

This study adopts a fresh approach to find the similarities between river planforms in contrast to many previous studies that have presented distinguishing characteristics and thresholds. This new approach links textural and morphological attributes of bedforms, termed morpho-texture, with process and hydrological regime thereby indicated. The study was carried out in depositional features of ephemeral rivers having a range of planforms and located in the Judean Desert. High-resolution terrestrial laser scanning was undertaken to extract morphological and textural (roughness) characteristics. Results strongly indicate that bars are statistically coarser grained than the adjacent thalweg or anabranches where depositional processes occur. This suggests universal processes within ephemeral rivers regardless of their planform, where rapid flow recession causes the coarse tail of the bedload to be deposited as bars whereas the finer fractions deposit in the thalweg and thereby prevent the development of bed armour.