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14 Cards in this Set
- Front
- Back
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what does vertical and lateral erosion do? |
they change the cross profile of a river |
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what does verticla erosion do? |
this deepens the river valley making it v-shaped. its dominant in the upper course of the river |
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what does lateral erosion do? |
this widens the river valley. its dominant in the middle and lower courses |
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4 processes of erosion> |
hydraulic erosion abrasion attrition solution |
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what hydraulic erosion and abrasion? |
hydraulic - the force of the water breaks down rock particles away from the river channel abrasion - eroded rocks picked up by the river scrape and rub against the channel, wearing it away |
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what attrition and solution? |
attrition - eroded rocks picked up by river smash into each other and break into smaller fragments. edges of rocks round off aswell solution - river water dissolves some types of rocks - chalk and limestone |
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how is eroded material transported? |
1. traction - large particles like boulders are pushed along river by the force of water 2. saltation - pebble sized particles are bounced along river bed by the force of water 3. suspension - small particles like silt and clay are carried along by the water 4. solution - soluble materials dissolve in the water and are carried along |
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deposition - what and when and why? |
this is when the river drops the eroded material its transporting when - happens when a river slows down why - river reaches its mouth, water is shallower, amount of material in water increases |
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how do waterfalls form? |
1. soft rock is eroded more than hard rock, creating a step in the river 2. as water goes over the step it erodes more and more of the soft rock 3. steep drop is created, - the waterfall 4. hark rock eventually undercut by erosion. becomes unsupported and collapses 5. collapsed rocks are swirled around at foot of waterfall where they erode softer rock by abrasion 6. overtime more undercutting causes collapses. waterfall will move back up the channel leaving a gorge |
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what do storm hydrographs show? |
shows the changes in river discharge around the time of a storm |
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how can the UK manage its water supply? |
1. transfer water from areas of surplus to areas of deficit 2. build more reservoirs to store more water 3. fixing leaky pipes would mean less water is lost during transfer. |
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what issues does water transfer have? |
1. dams and aqueducts (bridges used to transport water) are expensive 2. affect the wildlife that lives in river 3. political issues-people may not want to give water to other countries |
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how can uk reduce its demands for water? |
1. taking showers 2. running washing machines only when they are full 3. using hosepipes less 4. install water meters - paying for every drop of water they use |
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Features of a waterfall |
Gorge Plunge pool Overhang Hard rock Soft rock |
