Gravity currents frequently occur when excess suspended sediments are
flushed along a river and discharged into greater natural water
environments such as lakes, reservoirs, and estuaries. Gravity and
turbidity currents have been broadly investigated, but the effect of
aquatic vegetation on their propagation in natural waters still presents
several open questions. We conducted a series of laboratory experiments
to investigate how flexible vegetation affects the propagation and flow
structure of gravity currents on a constant slope. We used both rigid
cylinders and flexible synthetic plants to mimic natural submerged
vegetation canopies. By varying density configurations of the vegetation
array and comparing the outcomes of rigid cylinders and flexible plants,
the data showed distinct patterns based on array density and plant
morphology. A two-layer current was created when the array density is
large enough to redirect the flow, as opposed to sparser conditions
where the denser fluid passes swiftly through the array. Flexible
vegetation further suppresses the propagation speed of gravity currents
compared to arrays of rigid cylinder with the same density, highlighting
the importance of the multi-scale processes driven by complex plant
morphologies that are not represented by rigid cylinder arrays.