Factors affecting the volume
and the speed of a river.
Permeability of rocks
more permeable rocks
less surface runoff lead to
smaller volume of water in
its channel.
less permeable rocks
will have a larger volume
of water in its channel.
Size of drainage basin
if the drainage is large,
therefore there is more
surface area for rain to
fall on.
if the drainage is small,
therefore there is less
surface area for rain to fall on
or do not 'collect' as much.
Roughness of channel
lesser obstacle
smoother channel will have a higher speed.
it encounters obstacle
such as rocks, boulders, underwater
vegetation or an uneven river bed.
friction will slow down the river flow
and reduce the speed of the river.
Climate
hot and wet
equatorial
have a high volume of water.
generally dry
volume of water remains
low throughout the year.
distinct wet and dry seasons
the amount of water depends on
the amount of rainfall received each
season.
Presence of vegetation
sparse vegetation
does not allow much rainwater to infiltrate
the ground, thus increasing the flow of surface
runoff.
the volume of the river is larger.
abundant vegetation
allows more rainwater to infiltrate the ground,
thus its reducing the flow of surface runoff.
the volume of water
in the river is smaller.
vegetation intercepts rain and
allows more water to infiltrate
or seep into the ground
Wetted perimeter
if the perimeter is small, less
friction. Therefore, the river
will flow faster.
if the perimeter is large, the
river will flow slowly
Gradient of channel
if the gradient is gentle,
the river will tend to flow
slowly.
if the gradient is steep,
the river will flow quickly.
