Title: What causes Flooding
1What causes Flooding?
You know what a flood is . ??? Dont
you?? Well, can you identify three ways a flood
can be caused??
2W.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)
3What causes Flooding?
The river has overtopped its banks and spilled
onto the flood plain.
4Exceptionally heavy rain
Boscastle, U.K. summer 2004 flash flood.
5Flash Flood in a dry desert area (S.W. U.S.A.)
Heavy rain onto dry hard ground.
6Snow Melt flood in Spring thaw.
e.g. The Yukon River in Alaska, U.S.A.
7Monsoon wet season
Essential for rice growing But bad if there is
too much rain.
8After a Dam Collapses Teton Dan USA. 1976
Humans to blame
9As 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
10Nepal -deforestation
More people More farmland needed Trees cut
down Terraces made on hillsides Landslides and
more run-off More risk of flooding
11High Tides can cause the sea to flood the land in
a storm surge.
12Hurricanes cause storm surges too! e.g. Florida
U.S.A.
13Tsunami Flooding Submarine earthquakes cause
giant tidal waves e.g. S.E. Asia 2004
14Cyclone hits Bangladesh
Bangladesh has monsoon river floods and cyclone
sea floods. Coastal areas have some concrete
shelters.
15Tropical Islands threatened by sea level rise
caused by Global Warming. e.g. The Maldives
16GeoBingo
1. 2. 3. 4. 5.
5. 6. 7. 8.
9. 10.
17GeoBingo
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