Flooding

Question 1

What is flooding

Answer 1

Flooding occurs when a river has too much water in its channel and it spills onto the surrounding land

Question 2

What are some physical causes of flooding

Answer 2

Heavy rainfall
Long periods of rain
Snowmelt

Question 3

What are some human causes of flooding?

Answer 3

Deforestation
Urbanisation

Question 4

What is deforestation

Answer 4

Removing trees reduces the amount of water intercepted by the tree and therefore increases run off towards the river
(Cutting down trees)

Question 5

What is urbanisation

Answer 5

Towns and cities have more impermeable surfaces ( doesn’t let any water through) this means the water just sits on the top and builds up to become a flood.
Rain falling on concrete and tarmac is unable to soak into the ground.
Gutters and drains then carry the water quickly and directly to the river.

Question 6

What are the 6 steps of flooding from heavy rainfall

Answer 6

1. Heavy rainfall
2. Rain soaks into ground
3. Water quickly reaches river
4. Water runs over the surface
5. River level rises
6. River floods

Question 7

How are floods most commonly made

Answer 7

If the water is unable to soak into the ground it stays in the surface , then it flows quickly downhill into a river

Question 8

What do roots on a tree help with

Answer 8

They take up water to reduce the amount reaching the river
They slow down the movement of the water

Question 9

What do the leaves of a tree help with

Answer 9

They act as an umbrella to stop the rain from hitting the ground.
The water on the leaves evaporates and doesn’t reach the ground

Question 10

Where is somewhere that had a flood?

Answer 10

Biescas in northern Spain

Question 11

What is a famous river?

Answer 11

The Amazon river

Question 12

What can happen if a house is flooded? (Effects of flooding)

Answer 12

Furniture can be destroyed and expensive to replace.
Insurance may be expensive to get in the future

Question 13

What can happen if a farm is flooded? (Effects of flooding)

Answer 13

Farm animals may drown
Crops can be destroyed. In poor countries this means people starve.

Question 14

What can happen if roads are flooded? (Effects of flooding)

Answer 14

Sewage systems may overflow. Causing drinking water to become contaminated.
Travel and transport can be disrupted as roads are under water or badly damaged.

Question 15

Is this positive or negative?
Flood waters bring mud/minerals (known as silt) from the river onto the floodplain and that makes the soil fertile for farming.

Answer 15

Positive

Question 16

Is this positive or negative?
Flooding can flush out pollution from the land around the rivers and make the land more useable.

Answer 16

Positive

Question 17

Is this positive or negative?
The pools/lakes created by a flood provide breeding areas for fish/prawns which are a food source for people

Answer 17

Positive

Question 18

What is a SOFT way to prevent floods?

Answer 18

Planting trees in the river basin. The trees act as a break on rainfall and reduce the amount of rain reaching the ground. Trees also use up water as they grow.

Question 19

What is another name for planting trees?

Answer 19

Afforestation

Question 20

What are some HARD ways to prevent floods?

Answer 20

Make the river channel larger and deeper to hold more water.
Walls called flood embankments are built to increase the height of the river channel.
Flood relief channels can be built around towns to divert excess water out of rivers and reduce the risk of flooding.

Question 21

What is hard engineering?

Answer 21

A techniques used to prevent erosion and flooding. They are highly visible man made structures used to stop or disrupt natural processes.
They usually have a negative impact on the environment

Question 22

What is soft engineering?

Answer 22

It works with nature to protect rather than trying to stop natural processes. It uses ecological principles ( like planting trees) .
It has a less negative impact on the environment
It’s less expensive

Question 23

What is an example of hard engineering

Answer 23

Dredging
Using a digger to make the river channel deeper and larger

Question 24

What is an example of soft engineering?

Answer 24

Planting trees