MISMOS: A MICROSCALE MORPHOLOGY SYSTEM

PERILLO, G.M.E.; NUCCIARI, L.; ALQUINGA SALAZAR, Y.C.; GENCHI, SIBILA A.; PERILLO, V.L.; PICCOLO, M.C.

SANTIAGO DE CHILE

Conferencia; 2022 Particles in the Americas Conference (PiA 2022); 2022

Particles in the Americas (PiA)

Microscale geomorphology, flow dynamics, and sediment transport on a beach arerather complex to study due to both their large spatial and temporal variability, and the veryshallow flows that are involved in resolving the processes. In fact, there is no directinstrumentation that can be employed to map in detail the micromorphology nor to measure flowvelocities or directions. To overcome these drawbacks, we developed MiSMoS, a system tomap surface, small scale morphologic features (i.e., ripples, rills, small channels, sedimenttransport) and current velocities having flow depths smaller than 5-10 cm. The systemcomprises a 1.6-m by side square aluminum structure with a total of 6 rails (L-shaped) overwhich a cart with 3 Teflon wheels can roll freely. The cart is designed so it can connect (for theinitial experiments) a Nikon Cooplpix L830 Camera (16 Mpx, focal distance 23-855 mm, f3.0-6.5) and has a 16-cm LED ring at its base powered by a battery. The lens of the camera are 60cm above the surface to be scanned. MiSMoS has two operational procedures. For highresolution mapping, the cart is manually moved sequentially every 12 cm along the rails and,then, moved to the adjacent rail to start the sequence again that is repeated until all rails weresurveyed. For flow and sediment transport measurements, the cart is kept still in one positionover the site of interest and movies of the process are taken for the required time. Highresolution 3D DEMs are obtained from the photomosaics using Structure-from-Motion (SfM)procedures, while flow studies are done using Particle Image Velocimeters (PIV). Sedimenttransport estimation are made by tracking single particles on the movies.