Flooding Flashcards
1
Q
Human Causes
A
- Afforestation
- Impermeable surfaces
- Urbanisation
- Channelisation
2
Q
Natural Causes
A
- Melting snow/Ice
- Heavy rainfall
- Rocks act as surface run off
- Hard soil
3
Q
Types of flood management
A
- Afforestation (Soft Engineering)
- Levees (Hard Engineering)
- Dams (Hard Engineering)
- Retention Ponds (Hard Engineering)
- Flood Warning System (Hard Engineering)
- Floodplain Zoning (Soft Engineering)
- Channelisation (Hard Engineering)
- Do Nothing (Soft Engineering)
4
Q
Afforestation
A
- Trees slow down the flow of water towards the river channel and also allow more interception
- £30’000 per Hector/Ha
5
Q
Levees
A
- Increases the potential of maximum are of the river channel allowing it to hold more water before it bursts its banks
- £8000 per metre/M
6
Q
Dams
A
- Built to control discharge
- Holds back water allowing it to be released in a controlled way
- £5-25 Billion
7
Q
Retention Ponds
A
- Allows run off to be temporarily stored and in turn lessens the risk of flooding
- £25’000
8
Q
Flood Warning System
A
- Allows evacuation of areas likely to flood and therefore reduction in damage by warning people in advance
- £1.3 Million
9
Q
Floodplain Zoning
A
- Considers the floodplain and try’s to avoid building on the areas which are most likely to be flooded.
- Area closest to channel is often used for farming
- Potentially free/ Low cost
10
Q
Channelisation
A
- Reduces water friction with the bed and banks speeding up water flow
- Gets water away and downstream from an area quickly
- £500 per Metre/M
11
Q
Do nothing
A
- Accept that flooding is a natural process and allow the river to flood as it pleases without control
- Free
12
Q
Hard Engineering
A
- Expensive
- Often has negative impact on river and surrounding environment
- Works against nature
- Man made
13
Q
Soft Engineering
A
- Work with nature
- Often cheap
- Ecologically sensitive
14
Q
CASE STUDY:
-Tewkesbury floods 2007-
CAUSES
A
- Vast flat land which was fertile
- River Severn and Avon confluence
- Impermeable surfaces
- No flood defences
- Low pressure in Calais
- 140mm of rainfall in only a few hours
- In a water Basin
- Large amounts of construction on a flood plan
- Soils were already saturated
- Size of rivers weren’t big enough
- Summer was wettest recorded
15
Q
CASE STUDY:
-Tewkesbury floods 2007-
EFFECTS
A
- 3000 people without clean drinking water
- Damaged services
- Pathways flooded
- Power supplies cut off
- Residents evacuated
- All four roads into Tewkesbury were cut off
- 4000 homes and 500 businesses flooded
- Clean tap water contaminated
- Some residents were stranded
- Tourism and economy effected
- Sewerage pipes burst
- House prices dropped due to lack of insurance
- 8 weeks before water supply is restored
- Damaged infrastructure
- 8 months to refurbish the town
- People possessions ruined
- Tewkesbury became isolated
16
Q
CASE STUDY:
-Tewkesbury floods 2007-
RESPONSES
A
- Access to boats
- Doctors moved to the council offices
- Temporary shelters put in place
- Food donated
- High volume pumps used to save electricity station
- 137 portaloos deployed
- 1400 Water bousers deployed
- Boundary walls put in place
- Flood warning put in place
- £25 Million spent on roads
- Bottled water handed out (10L per person per day)
- Army deployed
- Rescue teams from Cheshire
- Residents given sandbags
17
Q
CASE STUDY:
-Pakistan floods 2010-
CAUSES
A
- Monsoon rains causes flash floods
- Near the Indian ocean so lots of evaporated water
- Groundwater and surface run off
- Indus river has a flood plain of the whole of Pakistan
18
Q
CASE STUDY:
-Pakistan floods 2010-
EFFECTS
A
- 796,095km² of land covered in water
- 14 million homeless
- Death toll 2000
- 20 million directly effected
- Asked for $460 Million relief aid, only 20% of this was received by August 2010. The UN was concerned that aid wasnt arriving fast enough
- World Health Organisation stated ‘10 million people drinking unhealthy water’
- Widespread disease such as cholera
- 84 out of 121 districts effected
- 1.8 million homes destroyed
- $4 Billion worth of damage to infrastructures, and $500 million on crops and agriculture. Overall cost= $43 Billion
19
Q
CASE STUDY:
-Pakistan floods 2010-
RESPONSES
A
- Ensure adequate public health of the flood affected population through an integrated approach or ‘Survival Strategy’ combining safe water, sanitation, hygiene and healthy nutrition levels
- Provided food assistance and other social protection measures to offer a basic safety net, especially to the most vulnerable, until peoples livelihoods are restored
- Support durable solutions through the provision of shelter assistance prioritizing shelter solutions that can span emergency shelter, transitional shelter and core housing needs.
- Restore on and off farm livelihoods, with a focus on agriculture, livestock and protection and restoration of productive assets
- Restore basic community services and supporting the re-establishment of public administration, health and education systems
