The science dealing with the morphology (form) and dynamics
of streams and rivers.
The natural river system consisting of (1) the drainage basin,
watershed, or sediment source area, (2) tributary and
mainstem river channels or sediment transfer zone, and (3)
alluvial fans, valley fills and deltas, or the sediment deposition
The vertical distance above a design stage that is allowed for
waves, surges, drift, and other contingencies.
A dimensionless number that represents the ratio of inertial to
gravitational forces in open channel flow.
A basket or compartmented rectangular container made of wire
mesh. When filled with cobbles or other rock of suitable size,
the gabion becomes a flexible and permeable unit with which
flow- and erosion-control structures can be built.
General scour is a lowering of the streambed across the
stream or waterway at the bridge. This lowering may be
uniform across the bed or non-uniform. That is, the depth of
scour may be deeper in some parts of the cross section.
General scour may result from contraction of the flow or other
general scour conditions such as flow around a bend.
That science that deals with the form of the Earth, the
general configuration of its surface, and the changes that take
place due to erosion and deposition.
Structure placed bank to bank across a stream channel
(sill, check dam):
usually with its central axis perpendicular to flow) for the
purpose of controlling bed slope and preventing scour or
A geomorphic term used for streams that have apparently
achieved a state of equilibrium between the rate of sediment
transport and the rate of sediment supply throughout long
A rock fragment whose diameter ranges from 2 to 64 mm.