Sediment transport is the movement of solid particles (
sediment), typically due to a combination of gravity acting on the sediment, and/or the movement of the
fluid in which the sediment is entrained. Sediment transport occurs in natural systems where the particles are
clastic rocks (
sand,
gravel,
boulders, etc.),
mud, or
clay; the fluid is air, water, or ice; and the force of gravity acts to move the particles along the sloping surface on which they are resting. Sediment transport due to fluid motion occurs in
rivers,
oceans,
lakes,
seas, and other bodies of water due to
currents and
tides. Transport is also caused by
glaciers as they flow, and on terrestrial surfaces under the influence of
wind. Sediment transport due only to gravity can occur on sloping surfaces in general, including
hillslopes,
scarps,
cliffs, and the
continental shelf—continental slope boundary.