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Geography End of Year 8 Exam - Coggle Diagram
Geography End of Year 8 Exam
Weathering
Types of Weathering
Freeze - Thaw Weathering (Physical)
Exfoliation or Onion - Skin (physical)
Chemical (Chemical)
Biological (biological)
Definition
Weathering is the process of rock being worn down by the weather
Rivers
The Bradshaw Model
This model shows the changes that occur when the river flows from it's source to the mouth. (left to right)
River Erosion
Hydraulic Action
The force of the river against the banks causes the air to be trapped in cracks. This pressure weakens the banks and eventually wears them away.
Abrasion
Rocks carried along the river wear down the river bed and banks.
Attrition
Rocks being carried together smash and break into smaller parts
Solution
Soluble particles are dissolved into the river.
River Transportation
Solution
minerals are dissolved into the water and carried along in a solution
Suspension
fine light materials are carried along the water
Saltation
Small pebbles and stones are bounced along the river bed
Traction
the river rolls large boulders along the river bed
River Features
Characteristics of the long profile
Upper Course
where the river starts and is usually an upland area. Slopes are steep - this can increase the velocity of the river after heavy rainfall, when discharge is high. The river channel is narrow and shallow here. The river's load is large in the upper course, as it hasn't been broken down by erosion yet. When discharge is high vertical erosion erodes the river bed and larger sediments are transported by traction.
Middle Course
here the gradient becomes less steep. The river channel gets deeper and wider as the bed and banks are eroded. The sediment load of the river gets smaller in size. Small meanders and a small floodplain can be found in this part of the river.
Lower Course
the final course of the river is where the land is a lot flatter. The river's load is fine sediment, as erosion has broken down the rocks. The river channel is at its widest and deepest as it flows towards its mouth. Deposition is the main process in this part of the river, which creates large floodplains and deltas.
Formation of a Waterfall
When rivers flow over different types of rock the soft rock underneath wears away faster than the hard rock below. In time a step develops and the river plunges as a waterfall.
Formation of a Meander
When water flows downstream the fastest current is on the outside of the bend and erodes that side making it deeper. while the slower current deposits deposition on the other side making the land uneven.
Ice
Pleistocene Ice Age
Ended 2.5 million years ago
Glacier
Rivers of ice formed from compact snow
Types of erosion
Freeze - Thaw
The ice melts and water seeps into the rock and freeezes
Plucking
As the glacier flows down pieces of rock become loos and the glacier pulls them along
Abrasion
Rocks and stones already in the glacier break and pull more rocks and stones along with them.
Land forms created in a glacial landscape
U-shaped valleys
Corries
Arete
Pyramidal peak
Africa and Kenya
Population
1.216 billion
Countries
54
Capital City of Kenya
Nairobi
Physical features of Africa
Sahara and other deserts
Ethiopian Highlands
Savanna or highlands
Swahili Coast
Rainforests