🌋Case Study - Caracas Local Hazards Flashcards
Where is Caracas?
Venezuela
How does infrastructure make Caracas vulnerable?
Infrastructure is poor and run across seismic faults
How many main water pipes run across a seismic fault?
3
How many people live per km2 in barrios?
25,000/km2
How is the population of the city growing?
Rapidly, 3.1% per year
Why may the main bridge have to be rebuilt?
Due to a slip in the plates
What is a major inequality in Caracas?
Economic, unequal wealth
Is there any planning around hazards in the city?
No, and none in the country as a whole
What is the issue with the government in Caracas?
There is a lack of stability
What hazards is Caracas exposed to?
Tropical storms
Earthquakes
Drought
Sea level rise
Landslide/rockfalls
What are social class divisions reflected by?
The occupancy of residential areas
How did members of the upper class gain wealth?
Through sale of land and real estate
Where do the upper class live?
On the Eastern margins of the valley and the Caribbean coast
What do the upper class homes avoid?
Landslide and earthquake risk
Where do lower class people live?
In hillside shanty towns overlooking the West and South
How do building regulations differ between the city centre and shanty towns?
On the hillside there are no building regulations and no means of escape, everything would be destroyed. In city centre, international building regulations and flat land provides safety
What is high in Caracas?
Unemployment
What percentage of Venezuela’s GDP is based on oil sales?
50%
What has the city focused its service in?
Banks, NGOs and shops
How do planned responses vary around the city?
Each company has its own individual planned responses, rather than city wide, common plans
What are the areas most at risk in Caracas?
Transportation and utilities as well as squatter settlements
Which university recently developed a framework plan for building disaster resilience?
Columbia Univeristy
What are the immediate disaster avoidance goals?
Strengthening critical infrastructure, housing stock and emergency services
What are the more intermediate goals?
Upgrading fragile housing units, creating detailed hazard maps and incorporating disaster education into cultural activities
What are the long term goals?
A fully redundant transport and water delivery framework, establishing legitimate land title for squatters and re-locating critical facilities
Which plate boundary is Caracas located on?
The South American and Caribbean boundary
At what rate are the plates moving?
2cm/year
How is flooding risk increased by the environment?
The steep slopes of the valley decrease movement time of run off
How could Caracas be cut off from the rest of the world in a major event?
If the single highway that links it to the airport and seaport is damaged. It is located in steep, landslide prone valleys.
What is the preferred hazard response by the government?
Risk zoning, due to lack of funds
Why is the city prone to landslides?
It is at the base of a valley, and tropical storms or tectonic activity can cause them
Why is the city prone to liquefaction?
Alluvial fans make up the valley floor, which are prone to liquefaction
What type of view do residents of the barrios have?
Fatalistic
Why do different groups respond to hazards in different ways?
Due to a lack of equality in the city
How are residents instructed to build their homes?
To orientate them parallel to any debris flows so to minimise the amount of material hitting the building
How are the streets laid out?
In a parallel pattern
GDP?
$17,000
Venezuela is the _______ wealthiest country
How it the wealth distributed?
70th
Uneven
Social: Where do the wealthy build their homes?
Away from earthquake prone areas
Built to international building standards
Social: Where do the middle class build their homes?
City centre
Mainly flat- deepest part of the basin = most shaking
Mainly apartments- high population density
Social: Where do the poor build homes?
Hillsides
Landslides + flooding
Shanty towns (barrios)
Social: How much of the city’s water is from 3 pipes?
How much is stored in the city?
95%
1 days supply in the city
Economic: Why does the building quality vary?
Wealth varies
50% of economy is oil
Most of the rest is services- low paid
Economic: How close is the bridge that connects Caracas to its sea and airports from collapsing?
Problems this would create?
23cm
Transport and commerce gone
Political: What has allowed squatters to build shanti towns?
Lack of building codes
Lack of regulation
Political: How long does the transport minister stay on average?
Problems with this?
6 months
Doesn’t stay long enough to do anything
Community responses to the risk?
Build in different areas
Government doesn’t have money to implement building codes
Local government response to risk?
Told to organise and plan disaster management plan- more coordinated and effective response
Include military, NGOs, public
Why is the local government disaster management plan unlikely to work?
Faces strong opposition from parties involved
So they won’t agree
Recommended that slums residents are educated in ….
Safer building techniques
What is the boundary like?
Situated on boundary of Caribbean and South American plates with faults running through the city and under the main airport.
When was the last major earthquake and how many did it kill?
In 1967 (mag 6.5) and killed over 300 people
What makes up much of the basin’s floor and what does this mean/
Alluvial fans. These are prone to liquefaction during earthquakes
Slope angles
Regularly exceed 80% making landslides and runoff major hazards in the Caracas basin
Where is the safest and therefore most valuable land ?
On the valley floor
What are the buildings of the wealthy like?
Many have earthquake resistant technologies such as using triangular steel reinforcement of shock absorbing foundations
How are the valley floor buildings spaced?
Widely spaced to enable easy evacuation
Issue with the water supply
All 3 supply lines cross major faults which could be lost in a disaster
Issue with the main road access to the airport and sea port
Crosses a fault as well as using a large bridge which is at risk of landslides
What is the Venezuelan economy based on?
Oil
Issues with being a service focussed economy regarding hazard response
Each organisation/service often plans its own response rather than following an organised city wide plan
What is the government like?
Democratic and relatively stable for South American standards
What has the high crime rate done?
Moved government focus away from hazard prevention
Why don’t slum dwellers care about what the government say?
Don’t have an address so don’t vote
What is the preferred method of management?
Risk zoning - Designating certain high risk areas of the steep valley sides as ‘no build zones
Issue with risk zoning
Limited by weak governance and the fact that most of the barrios (shanty towns) are constructed illegally
Who do the wealthy residents employ to build their offices?
Western builders to adhere to western building codes which are stricter
Who do the government fund?
Research bodies such as the Venezuelan foundation for seismological research
