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GCSE Physical Geography > Floods > Flashcards

Flashcards in Floods Deck (25)
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1
Q

Physical factors of flooding

A
  • Prolonged rainfall
  • Heavy rainfall
  • Snowmelt
  • Relief
2
Q

Human factors of flooding

A
  • Deforestation

- Building construction

3
Q

Flooding - Prolonged rainfall

A

After a long period of rain -> soil is saturated -> further rain cant infiltrate -> INCREASES surface runoff -> Discharge is increased quickly -> Flood

4
Q

Flooding - Heavy rainfall

A

Heavy rain -> Lot of runoff -> INCREASES discharge quickly -> Flood

5
Q

Flooding - Snowmelt

A

Snow or ice melts -> Lots of water into a river in a SHORT space of time -> INCREASES discharge quickly -> Flood

6
Q

Flooding - Relief

A

River is in the steep- sided valley -> Water reaches the channel quicker (water flows quicker) -> Discharge INCREASES quickly -> Flood

7
Q

Flooding - Deforestation

A

Cutting down trees stops interception of water

  • > Increases the volume of water reaching the channel
  • > INCREASES discharge
  • > Flood
8
Q

Flooding - Building construction

A

Buildings -> impermeable materials

  • > INCREASES surface runoff (drains quickly take runoff to rivers)
  • > INCREASES discharge
  • > Flood
9
Q

Examples of Hard engineering

A
  • Dams and reservoirs

- Channel straightening

10
Q

Examples of Soft engineering

A
  • Flood warnings
  • Preparation
  • Flood plain and zoning
  • ‘Don nothing’
11
Q

Hard engineering definition

A

Man- made structures built to control the flow of rivers and reduce flooding

12
Q

Soft engineering definition

A

Schemes set up to using knowledge of a river and it processes to reduce the effects of flooding

13
Q

Dams and reservoirs

A

Walls are built across river upper course lake is formed behind the dam
+ Store water -> reduces flooding
+ Used a drinking water
+ Used for hydroelectric power stations
- Very expensive
- Flood existing settlements
- Eroded material is deposited in the reservoir not the natural course (farmland is less fertile)

14
Q

Channel Straightening

A

Course is straightened (meanders are cut out by building straight channels)
+ Water moves out area quicker ( doesn’t travel as far)
- Flooding may happen down stream
- More erosion down stream - flowing faster

15
Q

Flood warnings

A
Environment agency warms people 
\+ Impact is reduced 
\+ Gives people time to more possessions upstairs 
- Doesn't stop a flood
- Difficult to get insurance 
- Might not have access/hear warnings
16
Q

Preparation

A

Buildings are modified to reduce damage
+ Less damage on buildings
+ People know what to do if a flood happens
+ Less likely to worry
- Doesn’t guarantee safety
- False sense of security
- Expensive to modify homes & businesses

17
Q

Flood plain & Zoning

A

Restrictions preventing building on areas likely to flood
+ Impermeable surfaces aren’t made
+ Houses/ roads aren’t damaged
- Limited in Urban areas
- To late for some areas which have been built on

18
Q

‘Do nothing’

A

+ Eroded material is deposited on the flood plain -> More fertile farmland

  • Risk of flood & impacts aren’t reduced
  • Flood will cause a lot of damage
19
Q

Places with high population densities means…

A

A higher demand for water

20
Q

The South east and midland are areas of…

A

Water deficit

21
Q

The North and West are areas of…

A

Water surplus

22
Q

Issues of Water transfer

A
  • Dams and aqueducts needed are expensive
  • Effects wildlife (fish migration)
  • Political issues -> People don’t want their water given to another country
23
Q

How the UK meets their water demand

A
  • Water transfer (Birmingham deficit - Wales Surplus)
  • Build more reservoirs
  • Fixing leaky pipes - less water is lost during transfer
24
Q

How to reduce demands of water

A
  • People can reduce the amount of water they use at home (taking showers, only putting the dishwasher on when its full)
  • Water companies said they want people to have water metres (charge for the exact volume of water they use)
25
Q

Reasons for an increasing demand of water

A
  • Population (higher demand)
  • Housing
  • Industry
  • Climate (Global warming, drought, water shortage)