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Geography
AS REVISION - AQA 2014




Name...............................

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RIVERS
RIVER PROCESSES


SEDIMENT SYSTEMS
Sediment in a river comes from a variety of sources. It may be from outside the river (exogenetic) that includes, mass movement, rill and
gully erosion and sheet wash. Or from within the rivers channel itself (endogenetic) that could be material from the stream bed…

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You should note the following:

Sand is easily transported at lower velocities.

More velocity is needed to pick up material than to carry it in suspension.

In times of highest discharge, velocity increases, as does erosion.

The division between Transportation and deposition is small. This means that only a small…

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3. Hydraulic action

The force of water that hits river banks, and then pushes water into cracks. Air becomes compressed, pressure increased and the
riverbank may, in time collapse.

4. Solution/corrosion

A continual process, which is as a result of the chemical composition of the water.






TRANSPORTATION
Once friction has…

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B A river entering the sea or a lake, reducing velocity

C Water becoming shallower

D Increase in load

E River overflows its banks, depositing material on the flood plain




RIVER CHANNEL LANDFORMS

V-SHAPED VALLEYS AND INTERLOCKING SPURS
In the upper part of a river, vertical erosion is common creating…

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OTHER LANDFORMS
Rapids

If the gradient of the river increases quickly or flows over gently dipping areas of harder rock rapids will result.

Flood Plains


At its most basic level this is land more likely to experience flooding.
If a river floods, silt is deposited on the land increasing its…

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Pools, riffles, and meanders

These features occur due to both erosion and deposition. Pools are areas of deeper water and riffles are areas of shallower water. A pool
has more erosion than a riffle, and is caused by turbulence.




Meanders

The reasons for the development of meanders remain unclear, but…

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RIVER TERRACES




As shown in the diagram above river terraces offer superb sites for the location of settlement. They are the remains of former flood plains
that lie far above the extent of present day flooding as a result of vertical erosion caused by rejuvenation.




INCISED MEANDERS
If land is…

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soil type,

drainage density,

tides,

Urbanisation.



COASTAL PROCESSES
INTRODUCTION
Of all the earth's natural environments, the coast is the most rapidly changing and dynamic. It can be defined in several ways, but at its
simplest, it is the place where land and sea meet and interact. The coast is under…

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There is limited direct sediment movement here as tidal currents are more important than wave action. Sewage outfalls, oil extraction and
fishing may occur.




BERMS AND RIDGES
On the beach itself, different features arise as a result of the action
and strength of waves on sand and shingle.

Berms are…

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