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Key words - Transportation. Traction – where large rocks and boulders are rolled along the river bed. Saltation – where smaller stones are bounced along the river bed in a leap frogging motion Suspension – where very small grains of sand or silt are carried along with the water
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Key words - Transportation. • Traction – where large rocks and boulders are rolled along the river bed. • Saltation – where smaller stones are bounced along the river bed in a leap frogging motion • Suspension – where very small grains of sand or silt are carried along with the water • Solution – where some material is dissolved (like sugar in a cup of tea) and is carried downstream.
Gradient/slope decreasing Source. Velocity/flow increasing Upland stream. Cumecs/discharge increasing Energy increases Lowland river. Mouth. • 30 25 20 15 10 5 0 • Distance from sea in Kms. Long Profile Height above sea level in meters. 0 50 100 150 200 250
Traction Heavy rocks and boulders are rolled along the river bed. Happens most in times of flood, when the current is strongest.
Saltation. Small stones and pebbles are ‘bounced’ along the river bed. Saltation can take place when the river flow is less than that needed for ‘Traction’ to take place.
Suspension Very small particles of sand or clay that are ‘suspended’ in the water. These particles will ‘settle’ if kept in a jar of water overnight and the water will look clear.
Solution. Takes place when material is dissolved in the water, it is invisible and does not colour the water. Occurs often in limestone landscapes where the water if very acidic. Some pollutants like weedkiller are also held in solution in the water
Shows the rate of flow needed Methods of transport Copy this picture into your books and add the title above and labels for each type of transport Traction Saltation Suspension Solution
Key Words - Erosion. • Attrition – where material is moved along the bed of a river, collides with other material, and breaks up into smaller and smaller pieces. • Corrasion – fine material rubs against the river bank. The bank is worn away, by a sort of sandpapering action called abrasion. • Corrosion – some rocks forming the banks and bed of a river are dissolved by acids in the water • Hydraulic action – the sheer force of water hitting the banks of the river.
