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STRATEGIES TO REDUCE IMPACTS OF NATURAL HAZARDS, image - Coggle Diagram
STRATEGIES TO REDUCE IMPACTS OF NATURAL HAZARDS
EARTHQUAKES
EDUCATION
People can be told how to make a survival kit containing things like food, water, a torch, a radio and batteries. The kits reduce the chance of people dying if they're stuck in the area.
Schools and companies should practise earthquake drills regularly to become familiar with evacuation in the case of an earthquake
People can be educated on what to do iXn the case of an earthquake. (e.g. stand in a doorway) and how to evacuate. This reduces deaths.
AID
helps to reduce the impacts, e.g. money-aid is used to rebuild homes, reducing homelessness.
receiving aid from governments or organisations in the form of food, water, money or service people (e.g. doctors/rescuers) makes aftermath of an earthquake easier
Eg: UNICEF, American Red Cross and
PREPARATION AND PLANNING
Firebreaks can be made to reduce the spread of fires.
Emergency drills can train and prepare for disasters and ensuring appropriate training most definitely reduces the impact
Future developments, e.g. new shopping malls, can be planned to avoid the areas most at risk from earthquakes. This reduces the number of buildings destroyed by an earthquake.
Having an evacuation plan, involving ensuring evacuation strategies are in place along with emergency shelter and food supplies being planned for.
Risk Assessment – Determining whether an earthquake event is probable or not and the damage it might cause.
Emergency services can train and prepare for disasters, e.g. by practising rescuing people from collapsed buildings
People are taught that if they are unable to be evacuated what they should do to protect themselves, e.g. go indoors to avoid falling ash and rock.
In earthquake-prone countries, people practise for an earthquake. They have drills in public buildings so that people know what to do in the event of an earthquake, helping reduce the impact and reduce potential deaths
Eg. Japan has Disaster Prevention Day on 1st September, where earthquake preparedness takes place nation-wide.)
Having an emergency response in place in the event of an earthquake or volcanic eruption, including stockpiling emergency supplies of tents, food, water and blankets.
Emergency kits, first-aid items, blankets and tin food are needed for the aftermath of an earthquake.
Preparing for an earthquake requires training for people, practising earthquake drills and paying attention to TV and radio
Example: Japan has a disaster preparedness day on 1st September where evacuation drills are held
BUILDING DESIGN AND LOCATION
building special foundations that absorb an earthquake's energy.
Building oil and water pipelines in tectonically active areas on rollers so that they can move with an earthquake rather than fracture.
BUILDING SAFE HOUSES BY APPLYING FEW GENERAL TECHNIQUES LIKE
small regular spaced windows - create fewer weak spots in walls
confined masonry
light roofs - more resistant
reinforced walls - walls crack but do not collapse, allowing occupants to escape
light walls and gables - Lightweight structures are subject to smaller forces and are less likely to fall
when the ground shakes
shock absorbers - absorb the tremors and reduce the magnitude of shockwaves and help buildings slow down
HOW TO MAKE BUILDINGS EARTHQUAKE RESISTANT?
Create a flexible foundation
Base isolation involves constructing a building on top of flexible pads made of steel, rubber, and lead. When the base moves during the earthquake, the isolators vibrate while the structure itself remains steady. This effectively helps to absorb seismic waves and prevent them from traveling through a building.
Shield buildings from vibrations - concrete and plastic rings are placed underneath to channel shockwaves
around the building
Counter Forces with Damping
Tuned dampers attached to beams use pistons and oil to convert the motion into heat and absorb shock.
Use earthquake resistant materials as they are responsible for the stability of the building
wood:
ductile material due to its high strength relative to its lightweight structure
futuristic material like bamboo and memory alloy:
Have the potential for greater flexibility and shape retention (Eg. Bamboo used in Peru.)
structural steel:
a component of steel that comes in a variety of shapes that allow buildings to bend without breaking.
High-rise buildings responds slowly, and shock waves are increased as they move up the building. If the buildings are too close together, vibrations may be amplified between buildings and increase damage.
BUILDING BUILDINGS AND STRUCTURES WITH
sheer wall: They are reinforced concrete walls with steel bars in them to reduce rocking movements and provide strength and resistance..
Base isolators- alternating steel and rubber absorbs shockwaves
sheer core : reinforced concrete used to strengthen the core
Counterweights - rolling weights on the roof that help counteract the energy waves.
Cross bracing involves reinforcing walls using two steel beams crisscrossing from corner to corner to brace the wall.
Constructing earthquake-resistant buildings reduces the number of buildings destroyed by an earthquake, having a smaller impact
BETTER PREDICTION, FORECASTING AND WARNING
Detecting foreshocks as they occur before the full earthquakes
Using sensitive instruments like strain-metres to measure Earth movements
Laser beams can be used to detect plate movement.
Some times water in wells is seen to fall. If local people notice these changes they can alert everyone to reach places of safety, away from buildings, reducing the negative impact.
Monitoring earthquakes areas to allow a prediction to give an early warning system. When and where an earthquake will strike can now be predicted along the active plate margins.
Seismometers to monitor Earth tremors and pick up the vibrations in the Earth's crust. An increase in vibrations may indicate a possible earthquake.
checking historical evidence - there are possibly trends in the timing of earthquakes in some region
Radon gas detection is used to measure radon gas which can escape through cracks in the surface of the Earth. Levels of radon gas can be monitored - a sudden increase may suggest an earthquake.
noticing strange and unusual animal behaviour, for example among fish (e.g. carp) and rats abandoning nests
predicting where future earthquakes may happen using data from past earthquakes e.g. mapping where earthquakes have happened shows which places are likely to be affected again, or where there is a gap where there haven't been major earthquakes along a fault line
recording changes in electrical conductivity
Plotting the number of recent earthquakes also helps in prediction
measuring crustal movement - the small-scale movement of plates
Example: based on an observation that the Parkfield segment of the San Andreas Fault breaks regularly with a moderate earthquake of about M 6 every several decades
VOLCANOES
DIGGING DIVERSION CHANNELS TO DIRECT LAVA FLOWS AWAY FROM SETTLEMENTS
PLANNING AND PREPARATION
Having an evacuation plan. This involves ensuring evacuation strategies are in place along with emergency shelter and food supplies being planned for.
Based on monitoring data, exclusion zones can be set up to ensure people are evacuated from areas likely to be affected before an eruption.
Emergency drills can train and prepare for disasters and ensuring appropriate training most definitely reduces the impact. .
Future developments e.g. new houses can be planned to avoid the areas most at risk from volcanic eruptions. This reduces the number of buildings destroyed by an eruption.
Firebreaks can be made to reduce the spread of fires
Having an emergency response in place in the event of a volcanic eruption, including stockpiling emergency supplies of tents, food, water and blankets.
Having emergency service preparation means better organisation and orderly conduct and knowledge what to do in case of emergency.
USING HAZARD MAPPING
This hazard mapping allows local areas to limit access to the danger zones and prevent buildings near to potential hazards from being built.
Exclusion zones can also be created, where no-one is allowed in them before, during or after an event.
This highlight areas at risk from the dangers associated with volcanic eruptions.
These maps can be used to restrict development and make people aware of the risks of living in certain areas.
Planning evacuation areas and removing the people most at risk from tectonic hazards is vital in reducing vulnerability.
An example is identifying locations at risk of pyroclastic flows, lahars, landslips and liquefaction and ensuring these areas are not used for building.
PREDICTION AND MONITORING
Infrared camera imagery where the images can potentially show the magma chamber and any build-up of hot gases, steam or lava.
By monitoring the movement of tectonic plates and changes in the surface of the volcano, the likelihood of a volcanic eruptions and forecast areas that should be prepared for one are predicted.
Thermal imaging allows a camera to monitor heat sources within the crust or volcano, it may help predict the onset of an eruption
Chemical sensors are used to measure increased sulphur levels
Ultrasound to monitor low-frequency waves in the magma, resulting from the surge of gas and molten rock
Tilt metres can be used to detect changes in the shape of a volcano providing an early warning indicator
Lasers can be used to detect the physical swelling of volcanoes
Increase in gas emissions from the magma rising and swelling of slopes (using monitors) are also signs of earthquakes
Seisometers can be used to record earth tremors as magma rises within a volcano.
Predicting when a volcano is going to erupt gives time for evacuation plans to be initiated, reducing the number of injury and death.
BUILDING TECHNIQUES
Strong building design to try amd prevent collapsing and general shelter
Buildings can't be designed to withstand lava flows or pyroclastic flows, but they can be strengthened so that they're less likely to collapse under the weight of falling ash, reducing the impact.
ADDING 'COLD' BOULDERS TO A LAVA FLOW IN ATTEMPT TO COOL THE LAVA AND STOP IT MOVING
AID
Aid helps to reduce the impacts, e.g. food aid stops people from going hungry.
Receiving aid from governments or organisations like food, water, money or people (e.g. doctors) reduces the impact and problems faced
**SPRAYING LAVA FLOWS WITH WATER TO COOL THEM DOWN AND STOP IT FLOWING
Eg. Eldfell Volcano, Heimaey where 1.5 billion gallons of ice-cold seawater was sprayed and successfully halted the lava.
EDUCATION
People can be told how to make a survival kit containing things like food, water, a torch, a radio, batteries and dust marks. The kit reduces the chance of people dying if they’re stuck in the area
Governments and other organisations can educate people about how to evacuate if a volcano erupts. This helps people to get out of danger quickly and safely, which reduces deaths.
