AUV for Shallow Water Hydrographic Surveys: Detecting Bedforms in Oued Loukkos Estuary (Morocco)

The images of the water-sediment surface provided by the AUV, showing dunes in different area of the loukkos river with a wavelength differs from 1 to 15 m; they are organized in series with quite the same lengths and the same wave amplitude. Another distinguishing criterion, revealed thanks to images of the water-sediment surface, seems to be the longitudinal morphology of dunes (planimetric dune morphologies). We were able to distinguish dunes with crests straight and slightly curvy form characterizing the two-dimensional dunes. Other forms of crests were distinguished, presenting the three-dimensional dunes are dunes with crest highly sinuous, catenary, linguoid, and lunate. The latter are often detected upstream or near the banks, remaining fairly stationary during the period of our study. The AUV images constitute the first step towards the understanding the distribution of different forms of dunes, in the Oued Loukkos estuary, thus well unveil the relationship between the sinuosity of dunes and hydrodynamic and sedimentary environmental conditions.