Rivers - created from Mind Map

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Erosion - the wearing away and removal of material by a moving force, such as a flowing river.

Transportation - The movement of eroded material

Deposition - occurs when material being transported by the sea is dropped due to the sea losing energy.

River profiles

Erosion - the wearing away and removal of material by a moving force, such as a flowing river.

Erosional landforms

Erosional and depositional landforms

Depositional landforms

Hydrograph - a graph which shows the discharge of a river, related to rainfall, over a period of time.

Hard engineering - the use of concrete and large artificial structures by civil engineers to defend land against natural erosion processes.

Soft engineering - managing erosion by working with natural processes to help restore beaches and coastal ecosystems.

Responses and effects

Abrasion - rocks carried along by the river wear down the river bed and banks.

Attrition - erosion caused when rocks and boulders transported by the river bump into each other and break up into smaller pieces.

Hydraulic action - the force of the river against the banks can cause air to be trapped in cracks and crevices. The pressure weakens the banks and gradually wears it away.

Solution - soluble particles are dissolved into the river.

Solution - soluble particles are dissolved into the river.

Suspension - fine solid material held in the water while the water is moving.

Saltation - particles bouncing down the river bed.

Traction - the rolling of boulders and pebbles along the river bed.

Long profile - the gradient of a river, from its source to its mouth.

Cross profile - the side to side cross-section of a river channel and/or valley.

Lateral erosion - sideways erosion by a river on the outside of a meander channel. It eventually leads to the widening of the valley and contributes to the formation of the flood plain.

Vertical erosion - downward erosion of a river bed.

Waterfall - sudden descent of a river or stream over a vertical or very steep slope in its bed. It often forms where the river meets a band of softer rock after flowing over an area of more resistant material.

Gorge - a narrow, steep sided valley, often formed as a waterfall retreats upstream.

Interlocking spurs - a series of ridges projecting out on alternate sides of a valley and around which a river winds its course.

Meander - a pronounced bend in a river.

Ox-bow lake - an arc-shaped lake which has been cut off from a meandering river.

Flood plain - the relatively flat area forming the valley floor on either side of a river channel, which is sometimes flooded.

Levees - embankment of sediment along the bank of a river. It may be formed naturally by regular flooding or be built up by people to protect the area against flooding.

Estuary - the tidal mouth of a river where it meets the sea; wide banks of deposited mud are exposed at low tide.

Impermeable - a material (e.g. rock) that does not allow water to infiltrate or pass through it.

Permeable - allowing water to soak through.

Dam and reservoir - a barrier (made of earth, concrete or stone) built across a valley to interrupt river flow and create a man-made lake (reservoir) which stores water and controls the discharge of the river.

(Channel) straightening - removing meanders from a river to make the river straighter. Straightening the river (also called channelising) allows it to carry more water quickly downstream, so it doesn't build up and is less likely to flood.

Embankments - raised banks constructed along the river; they effectively make the river deeper so it can hold more water. They are expensive and do not look natural but they do protect the land around them.

Flood relief channels - building new artificial channels which are used when a river is close to maximum discharge. They take the pressure off the main channels when floods are likely, therefore reducing flood risk.

Flood warning - providing reliable advance information about possible flooding . Flood warning systems give people time to remove possessions and evacuate areas.

Flood plain zoning - this attempts to organise the flood defences in such a way that land that is near the river and often floods is not built on. This could be used for pastoral farming or playing fields. The areas that rarely get flooded would therefore be used for houses, transport and industry.

Flood - occurs when river discharge exceeds river channel capacity and water spills out of the channel onto the floodplain and other areas.

Environment Agency (EA) - the organisation responsible for tackling environmental threats like pollution and flooding in the UK. It is directly funded by the government.

Fluvial processes - processes relating to erosion, transport and deposition by a river.

Immediate responses - the reactions of people as a disaster happens and in the immediate aftermath.

Long-term responses - later reactions that occur in the weeks, months and years after an event.

Primary effects - the initial impact of a natural event on people and property, caused directly by it; for instance, buildings collapsing following an earthquake.

Secondary effects - the after-effects that occur as indirect impacts of a natural event, sometimes on a longer timescale; for instance, fires due to ruptured gas mains resulting from the ground shaking.