Rivers. Location Profiles Processes Landforms. Main UK Rivers. Thames. 10. Spey. 1. Clyde. 4. 2. Shannon. 1. 7. Tees. 3. 5. Ouse. 9. 5. 4. Tay. 2. Severn. 8. 7. Trent. 6. 6. Forth. 9. 3. 8. 10. 2. 5. River Profile. Source. Mouth + Delta.
Mouth + Delta
Classic River Profile
Now Watch The Flash Presentation
On River Transportation
Force of water drags or rolls rocks along river bed.
Dissolved material is carried along in the water.
Pebbles are picked up and bounced along the river bed by flowing water.
Very light clays are held up in the water as it flows.
River Processes - Transportation
Force of water hitting off river banks causes them to wear down.
Stones carried by river hit into river bed and bank, eroding & scraping them.
Stones collide into each other knocking edges off – get smaller and rounder.
Rocks dissolve in water e.g. limestone
1 As the river flows it erodes downwards initially, due to the great energy it has. This happens mainly because of the process of corrasion (explain in detail for in exam!)
2 The river therefore forms a deep and steep sided channel. Over time freeze thaw (again explain) weathering acts upon the riverbank. This loosens the rock and soil.
3 As the rock & soil from the river bank breaks up, it is transported to the river by to gravity and the wash effect of rain on the soil.
the river is then transported
downstream by the river and is
deposited on its bed or on a river beach.
River erodes downwards due to fast flowing water carrying stones.
A deep/steep sided channel forms & weathering loosens soil on the banks
Rock & soil from river bank breaks up, falls into river due to gravity & rain
Eroded material transported downstream and deposited on river bed.
Now Watch The Two Flash Presentations
On Waterfall Development
Now Watch The Second Flash Presentation
On Waterfall/Gorge Development
gorge ~ soft ~ abrasion ~ collapses ~ cliff ~ deeper ~ plunge ~ hard
A waterfall is formed when a river flows over a layer of ______ rock, which is lying over a layer of soft rock. The _____ rock erodes more quickly. The hard rock sticks out forming a _____ in the river, which is a waterfall. The soft rock at the bottom of the waterfall/cliff is then eroded further to form a ____________ pool. This pool becomes bigger and ____________ as water swirls broken rock around. The hard rock is left unsupported and so eventually ______________. Over a long period of time the waterfall retreats backwards forming a narrow and steep sided valley called a _______. You will gain marks for describing either how the erosion occurs e.g. Hydraulic Action & __________.
Landforms Of The Middle & Lower Course
Inner Bend Outer Bend
Slow Flow Fast Flow
Low Energy High Energy
Small Rocks Large Rocks
Shallow Water Deep Water
River Beach River Cliff
( river beach )
Sand and shingle
of the river
Meander - River bend
Use your cross section diagram and the words in the same order as below to write 2 paragraphs explaining how meanders form.
Outer bend ~ fast flow ~ high energy ~ large rocks ~ erosion ~ deep water ~
Inner bend ~ slow flow ~ low energy ~ small rocks ~ deposition ~ shallow water
~ river beach
Alluvium river cliffs greatest speed deposition
erosion loss of energy meanders
The course of a river usually has many bends in it. These are
called___________. The _____________of water is on the
outside of the bend where _________takes place and the
channel is worn away to make___________The water flows
more slowly round the inside of the bend. This causes
__________________ and _________________ when the river
overflows its banks it deposits material called ______________ on the valley floor.
loss of energy
Green Valley Floor
Brown Valley Sides
An oxbow lake starts to form when large meanders develop close together (A). As their outer bends erode more, there is only a small piece of land remaining between them, called a neck (B).
Eventually the river erodes through the neck of the meander and makes a new straighter river channel (C). The river now flows down this channel and deposits material blocking up the old channel.
This leaves an oxbow lake in the old river channel and without a supply of water the lake can dry up (D). The lake may reform when there is heavy rain or flooding.
Layers Of Alluvium
River Bed Level Rises With Increased Deposition
Small Particles Deposited Away From River
Larger Particles Deposited Close To River
A floodplain is a flat area of land either side of a river, which floods regularly. The widest examples are found in the middle and lower course.
The river valley gets wider as meanders continue to grow, eroding back the sides of the valley.
The flat valley that forms is called a floodplain and develops as alluvium (mud/silt) sediment is deposited after a flood.
The smallest particles are found at the edge of the floodplain and the largest particles nearest to the river. The largest particles by the river bank form a mini ridge called a levee, which runs parallel with the river.