Fluvial Systems (Rivers). Click the link for an interactive tour through the water cycle. http://earthguide.ucsd.edu/earthguide/diagrams/watercycle/. Water that flows across land or is stored above ground is known as surface water.
Water that flows across land or is stored above ground is known as surface water.
They are the major route by which continental rain and the products of weathering reach the oceans.
Stream velocity-the speed at which water flows through a stream. The higher the velocity, the greater the erosive force of the stream
distance water travels
V = -------------------------------------------
time required to travel that distance
The higher the velocity – the more turbulent the flow.
The more turbulent the flow – the higher the erosive capacity.
-Transportation of sediment
-Erosion of channel (abrasion + dissolution)
-Deposition of sediment
suspended load = mud
bed load = sand + gravel
Discharge is the amount of water that flows past a point in a certain amount of time.
Discharge is dependent upon velocity, depth, and width of the stream.
Discharge = _______ x _____ x _____
from time to time AND place to place along
a single stream.
A stream’s discharge and velocity as well as the
sediment influx determine the morphological
features formed by a river system.
The following slides contain various river system
-Meanders develop because the velocity of water
in a stream is non-uniform.
-The maximum velocity occurs on the outsides of
the meanders where erosion occurs. Deposition of
alluvium occurs on the insides.
Point bar- a depositional feature formed when the velocity on the inside of the meander slows down and sediment falls out of suspension.
load is too large for a
single channel to carry
so numerous channels
____________ – deposit formed when a stream spreads out onto a less steep area
of abandoned meanders and oxbow lakes.
processes reactivate uplift in a region and
cause streams to begin downcutting again.
entire region from which a stream and its
tributaries receive their water.
of the stream channel the water rises up over the banks
and floods the adjacent lowland called the floodplain.
A stream rises to its
bankfull stage (just
filling channel) about
once every 1.5-2 years.
characteristics of the
stream channel are
adjusted to carry this
volume of water.
of miles wide and it may be
impossible to see the river from
parts of the floodplain.
Floods are a natural,
but the frequency and
severity of flooding can
be made worse by