Water on the land 0.0 / 5 ? GeographyWater and riversGCSEAQA Created by: gingeremilyCreated on: 08-05-14 20:03 Upper course: gradient, valley and channel size? Steep gradient, v-shaped valley, steep sides narrow, shallow channel 1 of 17 Middle course: gradient, valley and channel size? Gently sloping valley sides wider, deeper channel 2 of 17 Lower course: gradient, valley and channel size? Very wide, almost flat valley very wide, deep channel 3 of 17 Vertical erosion This deepens the river valley (and channel0 , making it v-shaped. It's dominant in the upper course. 4 of 17 Lateral erosion This widens the river valley (and channel). It's dominant in the middle and lower courses. 5 of 17 What are the four processes of Erosion? Hydraulic action, Abrasion, Attrition and Solution. 6 of 17 Hydraulic action The force of the water breaks rock particles away from the river channel. 7 of 17 Abrasion Eroded rocks picked up by the river scrape and rub against the channel, wearing it away. Most erosion happens by abrasion. 8 of 17 Attrition Eroded rocks picked up by the river smash into each other and break into smaller fragments. Their edges also get rounded off as they rub together. 9 of 17 Solution River water dissolves some types of rock, e.g. chalk and limestone. 10 of 17 Transportation of eroded material? Traction, Saltation, Suspension and Solution. 11 of 17 Traction Large particles like boulders are pushed along the river bed by the force of the water. 12 of 17 Saltation Pebbles-sized particles are bounced along the river bed by the force of water. 13 of 17 Suspension Small particles like silt and clay are carried along by the water. 14 of 17 Solution Soluble materials dissolve in the water and are carried along. 15 of 17 Deposition When a river drops the eroded material it's transporting. It happens when a river slows down (loses velocity) 16 of 17 Why rivers slow down and deposit material? The volume of water in the fever falls, The amount of eroded material in the water increases. 17 of 17
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