Key learning points

1. Floods occur when a river receives more water than the channel has capacity for.
2. Heavy and prolonged rainfall are the main physical causes of flooding.
3. Other physical causes of flooding are the shape and geology of the drainage basin.
4. Deforestation and urbanisation are the main human causes of flooding.

Keywords

• Prolonged rainfall - continuous rainfall that lasts for longer than expected

• Relief - the physical shape of the land in an area, including its height and steepness

• Geology - the physical structure of an area and what rocks and minerals exist there

• Deforestation - the complete removal of trees from an area

• Urbanisation - the increase in the proportion of people living in towns and cities rather than the countryside

Common misconception