What causes Flooding?

You know what a flood is …. ??? Don’t you??

Well, can you identify three ways a flood can be caused??

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)

What causes Flooding?

The river has overtopped its banks and spilled onto the flood plain.

Exceptionally heavy rain

Boscastle, U.K.

summer 2004

= flash flood.

Flash Flood in a dry desert area (S.W. U.S.A.)

Heavy rain onto dry hard ground.

Snow Melt flood in Spring thaw.

e.g. The Yukon River in Alaska, U.S.A.

Monsoon wet season

Essential for rice growing

But bad if there is too much rain.

After a Dam Collapses:

Teton Dan USA. 1976Humans to blame

Los Angeles U.S.A.

Humans to Blame

As cities get bigger there is more impermeable concrete and tarmac. The rain can’t soak into the ground.

Nepal -deforestation

More people

More farmland needed

Trees cut down

Terraces made on hillsides

Landslides and more run-off

More risk of flooding

High Tides can cause the sea to flood the land in a storm surge.

Hurricanes cause storm surges too!

e.g. Florida U.S.A.

Tsunami Flooding

Submarine earthquakes cause giant tidal waves

e.g. S.E. Asia 2004

Cyclone hits Bangladesh

Bangladesh has monsoon river floods and cyclone sea floods. Coastal areas have some concrete shelters.

Tropical Islands threatened by sea level rise caused by Global Warming. e.g. The Maldives

GeoBingo1.

2.

3.

4.

5.

5.

6.

7.

8.

9.

10.

GeoBingo1. 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