Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
“a cascade of water falling from a height, formed
when a river or stream flows over a precipice or steep
incline”
Upper c...
A waterfall is a steep drop along the course of a

river.
It has a ledge with water cascading into a
characteristic plun...
There is hard rock
overlaying soft rock
along the river bed.
Over time the river bed is
eroded by hydraulic
action, solution (usually
on softer rock such as
chalk and limestone) and
a...
Hydraulic
action
continues
to erode
the step
and
creates a
notch over
which the
water
flows.

Hydraulic action also erodes...
As the notch is
undercut,the
hard rock can
no longer
support itself
so collapses
and falls into
the plunge
pool.
Rocks and boulders enter the plunge pool because of the
collapsed notch. Abrasion and hydraulic action are now
working tog...
Erosion continues and the process repeats it’s self. The
plunge pool erodes and the notch is undercut, it will
collapse an...
As the waterfall retreats upstream it forms a steep
sided gorge which the river runs through.
Victoria Falls
Zambzi River
Border of Zimbabwe and Zambia

REMEMBER Zs

Not the highest or widest.
It is twice the hei...
Victoria Falls

Six main gorges:
First Gorge (the one the river falls into at Victoria

Falls)
Second Gorge
Third Gorge...
Victoria Falls

Made from:
Basalt

Sandstone
Victoria Falls
The Formation Of A Waterfall
Upcoming SlideShare
Loading in …5
×

The Formation Of A Waterfall

12,987 views

Published on

AS-Level Geography description of how a waterfall is formed with diagrams and a case study. Step-by-step formation.

Published in: Education, Travel
  • Be the first to comment

The Formation Of A Waterfall

  1. 1. “a cascade of water falling from a height, formed when a river or stream flows over a precipice or steep incline” Upper course Caused by erosion Vary in size
  2. 2. A waterfall is a steep drop along the course of a river. It has a ledge with water cascading into a characteristic plunge pool at the base. The rocks at the top of the waterfall are often hard and resistant, forming a cap rock, and softer rocks below are undercut. The waterfall may lie within a gorge and are often cause of gorges. Waterfalls often form when a band of resistant rock lies over softer, less resistant rocks.
  3. 3. There is hard rock overlaying soft rock along the river bed.
  4. 4. Over time the river bed is eroded by hydraulic action, solution (usually on softer rock such as chalk and limestone) and abrasion. The soft rock is less resistant to erosion than hard rock and therefore erodes at a faster rate causing a step along the river bed.
  5. 5. Hydraulic action continues to erode the step and creates a notch over which the water flows. Hydraulic action also erodes the base of the waterfall and creates a plunge pool which grows deeper and extends to behind the water. The notch protrudes further and the soft rock is undercut from the force of the water.
  6. 6. As the notch is undercut,the hard rock can no longer support itself so collapses and falls into the plunge pool.
  7. 7. Rocks and boulders enter the plunge pool because of the collapsed notch. Abrasion and hydraulic action are now working together to erode the plunge pool (it gets deeper) and notch. (These can sometimes cause potholes.) Splash back from the fall hitting the lunge pool can erode rock from the face behind the waterfall. This contributes to the debris in the plunge pool.
  8. 8. Erosion continues and the process repeats it’s self. The plunge pool erodes and the notch is undercut, it will collapse and hence restart the process. This causes the water fall to retreat upstream.
  9. 9. As the waterfall retreats upstream it forms a steep sided gorge which the river runs through.
  10. 10. Victoria Falls Zambzi River Border of Zimbabwe and Zambia REMEMBER Zs Not the highest or widest. It is twice the height of Niagra Falls and twice the width of Horshoe Falls. THE LARGEST SHEET OF FALLING WATER IN THE WORLD. HEIGHT: 1,708 metres WIDTH: 108 metres
  11. 11. Victoria Falls Six main gorges: First Gorge (the one the river falls into at Victoria Falls) Second Gorge Third Gorge (contains Victoria Falls Power Station) Fourth Gorge Fifth Gorge Songwe Gorge
  12. 12. Victoria Falls Made from: Basalt Sandstone
  13. 13. Victoria Falls

×