GCSE Geography Paper 1 – Physical 37.5% Paper 2 – Human 37.5% Paper 3 – Controlled Assessment 25%

Physical – Paper 1 Water on the Land Ice on the Land Restless Earth

Lesson Objective To understand the 4 types of erosion that occur in rivers To understand the 4 types of transportation that occur in rivers

http://www.juicygeography.co.uk/downloads/flash/erosion.swf

Key words - Erosion. Abrasion – Material carried by the river scrapes away the bed/sides of the channel Attrition – Stones smash into each other in the river, becoming smaller and smoother Hydraulic Action– The force of the water breaks off bits of the river bank. Water goes into cracks and causes pressure Corrosion – Material reacts with the water and dissolves

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.

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

Methods of transport Copy this picture into your books and add the title above and labels for each type of transport Shows the rate of flow needed Traction Saltation Suspension Solution

Lesson 2 To understand why rivers deposit material To understand how a river changes from source to mouth (long profile)

Long Profile

Cross Profile