Lock-release gravity currents propagating over roughness elements

Abstract The influence of bottom roughness on the development lock-release gravity currents is investigated through laboratory experiments using Particle Image Velocimetry. represented by arrays vertical LEGO bricks with a constant spacing while varying $$\lambda $$ ? , relative height elements to current depth. Depending may affect propagation: for small behaves like moving over smooth bottom, larger propagation speed reduced and internal structure current, including both head tail, significantly modified. As increases, stronger recirculation areas between develop interacting overlying layer giving rise small-scale vortical structures opposite sign within whole depth current. additional drag force induced adds significant complexity flow dynamics modifies characteristics