Geography - Floods - Flashcards in GCSE Geography

Created by: LunaShomeiRose
Created on: 30-12-18 22:27

Flooding occurs when a river...

bursts its banks and overflows onto surrounding land

1 of 7

prolonged (ongoing) rain can cause flooding through surface run-off. explain how

too much rain can saturate land (so it can't hold more water), so when more rain comes, it runs along the surface as it can't be absorbed

2 of 7

how does heavy rainfall cause floods through infiltration?

heavy rainfall = less chance of being absorbed by soil - less infiltration - runs off into river - faster it reaches river, more likely it will flood

3 of 7

how can the gradient of a valley affect chances of flooding?

steep valley is more likely to flood than a flatter valley because the rainfall will run off into the river quicker

4 of 7

*** does an increase in impermeable rock increase flooding risk? (permeable rock = rock that allows water through it's cracks/joints)

impermeable rock doesn't let water pass through it, increasing surface run off and therefore increasing flood risk

5 of 7

how does Vegetation effect flooding? (interception)

Vegetation absorbs water (known as interception). so less vegetation increases flood risk (e.g deforestation increases flood risk as water won't be intercepted and flow into the river)

6 of 7

when an area surrounding a river is built on, there is an increase in flooding risk. why? (impermeable surface)

amount of tarmac and concrete - water can't be absorbed on these surfaces (impermeable surfaces) so drains send more water to river, increasing flood risk

7 of 7

Other cards in this set

Card 2

Front

prolonged (ongoing) rain can cause flooding through surface run-off. explain how

Back

too much rain can saturate land (so it can't hold more water), so when more rain comes, it runs along the surface as it can't be absorbed

Card 3

Front

how does heavy rainfall cause floods through infiltration?

Back

Card 4

Front

how can the gradient of a valley affect chances of flooding?

Back

Card 5

Front

*** does an increase in impermeable rock increase flooding risk? (permeable rock = rock that allows water through it's cracks/joints)

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Geography - Floods