Factors affecting the volume
and the speed of a river.

if the gradient is steep,
the river will flow quickly.

if the gradient is gentle,
the river will tend to flow
slowly.

if the perimeter is large, the
river will flow slowly

if the perimeter is small, less
friction. Therefore, the river
will flow faster.

vegetation intercepts rain and
allows more water to infiltrate
or seep into the ground

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.

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.

distinct wet and dry seasons

the amount of water depends on
the amount of rainfall received each
season.

generally dry

volume of water remains
low throughout the year.

hot and wet
equatorial

have a high volume of water.

it encounters obstacle

friction will slow down the river flow
and reduce the speed of the river.

such as rocks, boulders, underwater
vegetation or an uneven river bed.

lesser obstacle

smoother channel will have a higher speed.

if the drainage is small,
therefore there is less
surface area for rain to fall on
or do not 'collect' as much.

if the drainage is large,
therefore there is more
surface area for rain to
fall on.

less permeable rocks

will have a larger volume
of water in its channel.

more permeable rocks

less surface runoff lead to
smaller volume of water in
its channel.