What causes Flooding

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What causes Flooding?
You know what a flood is . ??? Dont
you?? Well, can you identify three ways a flood
can be caused??
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W.A.L.T??? Today we are learning about the
different ways flooding is caused

• W.I.L.F???
• listen and make notes during PowerPoint
• carefully craft some written work afterwards
• (think of special terms for our GeoBingo)

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What causes Flooding?
The river has overtopped its banks and spilled
onto the flood plain.
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Exceptionally heavy rain
Boscastle, U.K. summer 2004 flash flood.
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Flash Flood in a dry desert area (S.W. U.S.A.)
Heavy rain onto dry hard ground.
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Snow Melt flood in Spring thaw.
e.g. The Yukon River in Alaska, U.S.A.
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Monsoon wet season
Essential for rice growing But bad if there is
too much rain.
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After a Dam Collapses Teton Dan USA. 1976
Humans to blame
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As cities get bigger there is more impermeable
concrete and tarmac. The rain cant soak into the
ground.
Los Angeles U.S.A. Humans to Blame
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Nepal -deforestation
More people More farmland needed Trees cut
down Terraces made on hillsides Landslides and
more run-off More risk of flooding
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High Tides can cause the sea to flood the land in
a storm surge.
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Hurricanes cause storm surges too! e.g. Florida
U.S.A.
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Tsunami Flooding Submarine earthquakes cause
giant tidal waves e.g. S.E. Asia 2004
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Cyclone hits Bangladesh
Bangladesh has monsoon river floods and cyclone
sea floods. Coastal areas have some concrete
shelters.
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Tropical Islands threatened by sea level rise
caused by Global Warming. e.g. The Maldives
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GeoBingo
1. 2. 3. 4. 5.
5. 6. 7. 8.
9. 10.
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GeoBingo
1. Flood plain 2. Boscastle 3. Flash flood 4.
Snow melt 5. Los Angeles
5. impermeable 6. deforestation 7. Florida 8.
Monsoon
9. wadi 10.storm surge