AQA AS Geography - Rivers, Floods and Management Content (FULL NOTES)

I hope this is helpful :).

Everything on the rivers content is according to the official aqa geography specification. Case study's regarding flooding and flood management are not included in this download.

Resources used: 

1. CGP AS-Level Geography Complete Revision Guide

2. www.geographyas.info

3. AQA Geography AS Student Book by Simon Ross, Bob Digby, Russell Chapmen and Dan Crowling.

4. My Revision notes - AQA AS Geography by Michael Raw

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  • Created by: Joe
  • Created on: 26-04-13 10:45

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Page 1

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Geography Revision Notes ­ Rivers, Floods and Management




AS level Geography
Rivers, Floods and Management
Water Balance
Water balance is worked out from inputs
(precipitation) and outputs (channel discharge
and evapotranspiration)
Wet seasons = increased precipitation which
exceeds evapotranspiration. Creating water
surplus.
Drier seasons = precipitation is lower than
evapotranspiration.…

Page 2

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Geography Revision Notes ­ Rivers, Floods and Management




Factors affecting Discharge
Discharge is the volume of water (in cubic metres, m³) that flows in a river per
second.

Calculations:

Depth x Width = Cross Sectional Area

Distance x Time = Velocity

Velocity x CSA (Cross Sectional Area) = Discharge






Storm…

Page 3

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Geography Revision Notes ­ Rivers, Floods and Management




Storm Hydrograph (Factors)




3

Page 4

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Geography Revision Notes ­ Rivers, Floods and Management




River Processes ­ Vertical and Lateral Erosion
The energy of a river flowing downhill causes erosion. The bed and banks of a
river can be eroded - making the river longer, deeper and wider.
A river's channel is eroded laterally and vertically.…

Page 5

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Geography Revision Notes ­ Rivers, Floods and Management




The Hjulström Curve









Capacity and Competence
Rivers Capacity - The maximum volume of load that a river can carry at a
specific point in its course.
The load of a river can be divided into different categories according to its
particle size.…

Page 6

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Geography Revision Notes ­ Rivers, Floods and Management




Cross Profiles
Cross Profile - shows the cross section of a river channel or river valley.
The valley cross profile changes during different stages of a river's long profile.
Upper stage - Steep V shape valleys , Vertical erosion
Middle Stage -…

Page 7

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Geography Revision Notes ­ Rivers, Floods and Management




The speed that a river flows at is affected by the efficiency of a river's channel.
The efficiency of a river's channel is dependent on a few factors.
The less friction between the water and the bed & banks the higher the…

Page 8

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Geography Revision Notes ­ Rivers, Floods and Management




Potholes

Potholes are small circular depressions in the river bed.
Potholes form when pebbles become trapped in small hollows and vertical
eddies as they develop, drilling the pebble into the bed in a circular motion ,
forming the pothole by corrasion.
Potholes…

Page 9

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Geography Revision Notes ­ Rivers, Floods and Management




They form where the gradient of the river is steep and the bed is composed
mainly of hard rocks.
The formation of rapids will increase the wetted perimeter due to its irregular
steps and its hard rocks that cause channel roughness.

Meanders…

Page 10

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Geography Revision Notes ­ Rivers, Floods and Management




of sedimentary load, a steep gradient and where there is a lot of variation in
discharge of the river changes regularly.
When the volume of load exceeds the river's capacity or the discharge of the
river drops, aggradation occurs the islands of…

Comments

Roshni

This is a really detailed document... and it looks veryyy helpful! I am using these notes to add to my notes, Thankyou much :))

Marta Kohls

Excellent revision guide! Highly recommended! :) 

yathavan

Awesome work!

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