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Features Of ErosionFeatures Of Erosion

By Jesse, Abdullahi, John, Nderitu By Jesse, Abdullahi, John, Nderitu and Angela.and Angela.

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WaterfallsWaterfalls• Waterfalls are usually

formed when a river moves over resistant bedrock and erodes it slowly while downstream it happens faster.

• As this happens material is plucked from a river bed which causes the waterfall to carve deeper into the riverbed and recede upstream

• part of the bedrock (hard rock) will later break off, exposing the soft rock, and form a waterfall.

• The rest is in the diagram on your right

OX BOW LAKESOX BOW LAKES• An ox bow lake is a U - shaped water body or

meander that is cut of by erosion to form a lake.

• They are formed when a river has a very curve us meander, which is nearly meeting the other side of the river.

• Due to erosion and deposition the neck of the meander becomes very narrow which allows water to pass straight, flowing past the old meander.

• Deposition then occurs, sealing of the meander.

• The deposition then totally covers up the meander so no more water can pass.

• Over time the closed meander completely cuts of from the rest of the river.

• The end result is a straight river separated from a curved C-shaped lake.

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OX BOW LAKESOX BOW LAKES

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V-shaped valleys.V-shaped valleys.

• In the upper course of a river, water flows at a high speed through a narrow channel with a steep gradient.

• As it does, so it cuts downwards.

• This vertical erosion results in a number of distinctive landforms including, the steep sloped v-shaped-valleys

• Through this the river flows in it's upper course.

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Formation of v-shaped-valleys.Formation of v-shaped-valleys.

• Vertical erosion leads to the development of steep sided, narrow valleys shaped like the letter V.

• The valley sides are steep due to the soil and loose rock being washed downhill following periods of heavy rainfall.

• The material is then added to the load of the river.

• The river itself forced to wind its way through protruding hillsides.

• These hillsides known as interlocking spurs restrict the view up or down the valley.

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RAPIDSRAPIDS• A river rapid is a section of a river

with a steep gradient, which cases an increase in the water velocity and the turbulence.

• A rapid is caused by the river becoming shallower and having some materials, like rocks, to be exposed above the flow surface.

• In rapids, water turns white because flowing water splashes over and around the rocks, and air bubbles mix with them.

• This colour is normally called “White water”.

• Rapids normally occur when the river bed is highly resistant to erosion.

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RapidsRapids• Rapids are categorized into several

classes:• Class 1- This is when the river has small

waves in fast flowing water and has very few obstacles, e.g. rocks.

• Class 2- When the river has wide channels and rapids , without many turns and obstacles.

• Class 3- This class has strong currents with many obstacles in the river.

• Class 4- Powerful rapids with big waves• Class 5-Very violent and dangerous

rapids with tight turns• Class 6- This last stage is the most

violent and strong. This rapid can cause death easily.

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RapidsRapids

• Many people use these river rapids to have fun.

• Rafting, is a sport which requires rapids.

• Rafting courses are also classified using these rapid

classes.

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