Hazards Flashcards
(199 cards)
1
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Natural Hazard
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A natural hazard is a perceived event that threatens both life and property. These forms of hazard thus pose a risk to human populations.
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Adaptation
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In the context of hazards, adaptaion is the attempts by people or communities to live with hazard events by adjusting their living conditions. Therefore people can reduce their vulnerability.
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Fatalism
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A view of a hazard event that suggests that people cannot influence or shape the outcome, therfore nothing can be done to mitigate against. People with such a attitude put in place limited or no preventative measures. In some parts of the world, the outcome of a hazard event can be said to be ‘Gods’ will.
Losses are inevitable
4
Q
Perception
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This is the way in which an individual or a group view the threat of a hazard event. This will ultimately determine the course of action taken by individuals or the response they expect from governments.
Influenced by religion, past experinces, socio-economic status , level of education and past experience.
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Risk
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This is the exposure of people to a hazardous event, presenting a potential threat to themselves, their possesions and the built enviroment in which they live.
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Why do people put themselves at risk?
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- Hazard events are unpredictable, difficult the frequency, magnitude or scale of a natural hazard scale.
- Lack of alternatives, due to social, political and economical factos people cannot simply uproot themselves from a place.
- Changing the level of risk, places that were once relatively safe may have become over time more at risk. Deforestaion for example may result in more flooding associated with tropical storms.
- Costs and benefits, if the benefits of a hazardous areas outweigh the risk that they are taking by being there. California cities.
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Vulnerability
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Vulnerebality to physical hazards means the potential for loss, varies over time and space, and losses vary geographically over time and among different social groups.
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Fear
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The perception of a hazard is such that people feel vulnerable to an event that they are no longer able to face living in the area and move away to regions percieved to be unaffected.
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Risk sharing
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This involves prearanged measuers that aim to reduce the loss of lifeand property damage through publiv education and awareness programmes, evacuation procedures, the provision of emergency medical, food and shelter supplies and taking out insurance.
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Prediciton
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The ability to give warnings so that action can be taken to reduce the impact of hazard events. Improved monitoring, information and communications technology have meant that predicitng hzards and issuing warnings have become more important in recent years.
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Magnitude
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The assesment of size and impact of a hazard
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Primary and secondary effects
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Primary effects are effects that are a result directly of that event, whereas secondary effects are those that result from the primary impacts of the hazard event.
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Primary and secondary effects
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Primary effects are effects that are a result directly of that event, whereas secondary effects are those that result from the primary impacts of the hazard event.
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Resilience
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The ability of individuals or communtiies to be able to utilise available resources to respond to, withstand and recover from the effects of natural hazards.
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Protection
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Protect the peopl and their possesions and the built enviroment from the impacts of hazards.
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Park Model
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Pre disaster - Relief, rehabilitation and reconstruction
Recovery can be a better quality of life or below the previous quality of life.
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The Hazard manegement cycle
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Mitigation
Preparedness
Response
Recovery
18
Q
Earths structure
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Mantle - This is made up of molten and semi-molten rocks containing lighter elements such as silicon and oxygen.
Crust - Even lighter because of the elements that are present, the most abundant being silicon, oxygen and aluminum, potassium and sodium.
Lithossphere - Consists of the crust and the rigid upper section of the mantle and is approximately 80-90 km thick. This is the section that consists of 7 large plates and a number of smaller ones.
Asthenosphere - Lies beneath this layer and is semi-molten on which the plates float and move.
Inner core - Solid ball of iron/nickel, very hot due to pressure and redioactive decay. Responsible for earths internal energy.
Outer core - Semi-molten
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Q
Oceanic crust
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6-10km
Less than 200 million years
3.0 density
Mainly basalt, silicon, magnesium and oxygen
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Continental crust
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30-70km
Over 1.5 billion
2.6 density (lighter)
Mainly granite, silicon, aluminum oxygen
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Plate tectonic theories of crustal evolution
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1912 Alfred Wegener published his theory that a single continent existed about 300 million years ago.
In 1912 he noticed that the coastlines of the east coast of South America and the west coast of Africa appeared to fit together like jigsaw pieces.
Further examination of the globe revealed that all of the Earth’s continents fit together somehow and Wegener proposed an idea that all of the continents had at one time been connected in a single supercontinent called Pangaea.
He believed that the continents gradually began to drift apart around 300 million years ago. This was his theory that became known as continental drift.
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Q
Sea floor spreading
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- The mid-atlantic ridge was discovered and studied along with a similiar feature in the Pacific ocean, examination of the crust either side of the mid-atalantic ridge suggested that sea floor spread was occuring.
- Movement of Oceanic crustal plates away from divergent/constructive plate boundaries such as in the middle of the Atlantic Ocean.
- Sea floor spreading implies that the earth must be getting bigger, as this is not the case then the plaes must be being destoryed somewhere to accomodate the increase in size at their midatlantic ridge.
- Plates diverge, magma rises up to fill the gap that is created, then cools to form new crust, over time the new crust is dragged apart and more forms between it, this creates mid ocean ridges
- Large areas of the oceanic floor were being pulled downward in process know as subduction.
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Convection Currents
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These plates move due to the convection currents in the asthenosphere, which push and pull the plates in different directions. Convection currents are caused when the less dense magma rises, cools, then stinks. The edges of where plates meet are called plate boundaries.
- Heat from the innter core convects through mantle into asthenosphere.
- Hot magma rises because it becomes less dense with heat.
- Magma is cooler at the top as it is further away from heat source. Becomes more dense and sinks back down to bottom.
- Cooler magma is reheated and begins to rise again, creating a loop called a convection current.
These circular movements create drag on the base of the tectonic plates causing them to move.
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Ridge Push/Gravatational sliding
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At construtive boundaries the upwelling of hot material at ocean ridges generates a buoyancy effect that produces the ocean ridge which stands some 2-3km above the ocean floor. here oceanic plates experience a force that acts away from the ridge, known as ridge push, which is a result of gravtiy acting down the slope of the ridge.
The occurrence of the shallow earquakes, resulting from the repeated tearing apart of the newly-formed crust, indicates that there is also some frictional resistance to this force.
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Slab pull
- At destructive plate boundaries, denser crust is forced under the less dense crust when they cinverge, the sinking of the plate edge pulls the rest of the plate towards the boundary and down into the mantle. This is called SUBDUCTION.
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Destructive plate margin
- Denser oceanic plate subducts below the continental.
- The plate subducting leaves a deep ocean trench.
- Fold mountains occur when sediment is pushed upwards during subduction.
- The oceanic crust is melted as it subducts into the asthenosphere, friction with the upper mantle creates heat.
- Extra magma created causes pressure to build
- Pressurised magma forces through weak areas in the continental plate.
- Magma is also less dense than the continental crust and therefore will rise.
- Explosive, high pressure volcanoes erupt through the continental plate, known as composite volcanoes.
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Constructive plate margin
- Two plates of the same type move away from each other.
- Magma rises between the gap left by the two seperating, forms new land when it cools.
- Volcanoes form where magma rises, magma is created by pressure release at the margin causing the mantle to melt.
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Conservative plate boundary
- Between any crust the parallel plates move in different direction or at different speeds. No plates are destoryed so no landforms are created. When these plates move, a lot of pressure is built up.
- When pressure releases they jerk and release energy
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Landforms associated with plate movements - Ocean ridges
- The longest continuous uplifted features on the surface of the planet, yet they are formed when plates move apart from each other in oceanic areas.
- The space between the plates is filled with basaltic lava upwelling from below to form a ridge. Volcanic activity occurs along these ridge lines, forming submarine volcanoes which can sometimes rise above sea level.
Construtive plates
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Collision
- Two plates of the same density move towards each other.
- Due to their similiarty little or no subdiction will take place. The plates therefore come together and fold.
- This creates mountain ridges
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Landforms associated with plate movements - Rift valleys
- Plates diverge at constructive boundarie, magma beneath the land causes the continental crust to bulge and fracture, forming fault lines.
- As the plates move apart the crust between the parallel faults drop down to form a rift valley.
- For example the east afrcian rift system is a series of rift valleys that strech from mozambique to the red sea.
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Landforms associated with plate movements - Deep sea trenches
Where oceanic and continental plates meet, the denser ocean plate is forced under the lighter continental one, the downwarping of the oceanic plate forms a very deep part of the ocean known as a trench.
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Landforms associated with plate movements - Island arcs
- During subduction the descending plate encounters hotter surroundings and this coupled with heat generated from fiction begins to melt the plate, as this material is less dense that the surrounding asthenosphere it begins to rise towards the surface as plutons of magma.
- This rise to the surface to form complex, composite an explosive volcanoes.
- A line of volcanic island can form if this happens of shore.
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Landforms associated with plate movements - Young fold mountains
- Collison boundaries, two plates of continental crust, same density means there is no subduction.
- As plates move towards each other the edges and sediments are forced into fold mountains. Very little subdiction can occur so not volcanism.
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Where can volcanoes form
- Oceanic ridges
- Rift valleys
- Subduction zones (destructive boundaries)
- Hot spots
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Volcano formation - Oceanic ridges
- Plates moving apart at constructive boundaries, magma forces its way to the surface and cools creating new crust, as the plates move away this new crust is carried away from the ridge (sea floor spreading).
- Volcanoes here are fairly gentle, low viscosity, basaltic. Frequent but effusive.
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Volcanic formation - Subduction zones
- Oceanic plate subducts and decends under the continental plate, the deeper it goes the hotter surroundings become, this together with heat generated from friction begins to melt the oceanic plate into magma.
- This magma is less dense than its surrounding material and therefore rises as plotuns of magma, they reach the surface and form volcanoes.
- Andesitic lava, high viscosity, composite and more explosive volcanoes.
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Volcanic formation - Rift valleys
- At constructive margins in continental areas such as east africa, the brittle crust fractures as sections of it move apart. Areas of crust drop down between parallel faults to form rift valleys, the crust here is much thinner suggest that the tension is causing the plate to thin as it sarts to split, as the crust gets thinner magma can more easily force its way to the surface.
For example Mount Kenya in the East African Rift system
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Volcanic formation - Hot spots
- A high concentration of magma below the crust is called a hotspot, a plume of magma rises to towards the plate above, heating the crust and causing it to fracture and thin, forcing its way up anf forming volcanoes.
- Forms shield volcanoes, baslatic lava, effusive.
- The hot spot is stantioanry so as the plate moves over it a chain of islands is formed.
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Fissure volcano
- Basaltic lava
- Lava can pour out in a number of places and in multiple directions, flat gentle slope.
- Construtive boundary
- Low silica content, low viscosity, this allows bubbles to escape and therefore pressure cannot build and they arent explosive.
- Effusive, gentle and frequent
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Shield volcano
- Result of constructive plates and hotspots.
- Basaltic lava
- Single vent, gentle slope byt steeper than fissure and taller.
- Basic, low silica content, low viscosity, bubbles cant be trapped, pressure doenst build, effusive and frequent.
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Dome
- Destrutive boundary
- Explosive
- Andesitic/Rhyollitic
- Can be very acidic, high silica content and more visocus if it is rhyolitic, trapping gass and building pressure.
- Steeper sides and more unstable.
- little lava flow
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Ash-Cinder
- Ash/TEPHRA more common
- Deposited erupted material
- Andesitic, between basaltic and rhyolitic.
- Steep sided, smaller, conical.
- Destructive boundary
- Explosive
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Composite
- Steeper sides, much larger .
- Destructive
- Andesitic or Rhyolitic
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Caldera
- Rhyolitic and Andositic
- Much larger, form when the crater collapses, forms a caldera out of the old cone.
- Steep rimmed
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Silica content
- Destrutive plate boundaries have higher silica content as they become contaminated with this and other sediment as they move up through the continental crust.
- Contiental crust is HIGH silica content.
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Magnitude
VEI Volcanic expolsivity index
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Primary impacts
- TEPHRA
- Proclastic flows
- Lava flows
- Volcanic gases
- Land slides
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TEPHRA - Primary impact VOLCANO
- Volcanic material ejected into the atmosphere including ash and volcanic bombs.
- Bombs can fall to the ground within 2 miles of the vent.
- Eruption columns of gas can reach more than 12 miles into the air.
- Volcanic ash in cloud can pose a hazard to aviation, last 15 years 80 commercial jets have been damaged through inadvertantly flying into ash.
- Finer pieces of TEPHRA can kill vegetation and cause long term health impacts to people.
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Pyroclastic flows - Primary impact VOLCANO
These are very hot, over 800 degrees celcius, gas charged, high velocity flows that make up a mixture of gas and TEPHRA. They usually flow down the sides of the volcano at speeds of around 700km per hour.
Mount Unzen 1991 killed 43 people
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Volcanic gases - Primary impact VOLCANO
These include carbon dioxide, carbon monoxide and sulphur dioxide.
Dangerous to people as they are toxic.
Cracks in teh ground allow for gases to reach the surface.
Carbon dioxide is heavier than air and can be trapped in low areas in high concentrations.
E.G
1986 carbon dioxide emission from the lake in the crater of Nyos cameroon killed 1,700 people.
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Secondary impacts - Volcanoes
- Lahars
- Flooding
- Tsunamis
- Acid rain
- Climate change
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Landslides - Primary imapact volcanoes
- Rapid downhill movement of rocky material, snow and ice.
- They can be entire collapses of the volcanoes sumit.
- Heavy rainfall, large earthquakes or volcanic events can cause them. SO COULD BE SECONDARY
Mount rainer, washington
Mount st helens eruption 1980, washington
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Lahars - Secondary impact VOLCANO
- Melted snow and ice as a result of the eruption comined with volcanic ash forms mud flows that can move down the course of rivers and valley at high speeds.
- 20-40 kph
- It can orginate from melting snow/ice, water from a glacier melted by a pryoclastic surge.
- Can happen when the volcano is quite.
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Flooding - - Secondary impact VOLCANO
When a eruption melts glaciers and ice flooding can be a result.
E.G
Iceland in 1996 when the Grimsvotn volcano erupted melting a glacier.
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Tsunamis - Secondary impact VOLCANO
Sea waves generated by violent volcanic eruptions.
E.G
Krakatoa in 1883, tsunami was estimated to kill 36,000 people.
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Acid rain - Secondary impact VOLCANO
- Sulfure emitted from eruiptions can react with water droplets in the atmosphere to create acid rain, this can cause corrosion and harm vegetation.
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Climate change - Secondary impact VOLCANO
The ejection of huge amount of debris into the atmosphere can reduce global temperatures.
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Prediction of volcanoes
- Locating volcanoes is straightforward but prediction is difficult.
- Colomibian volcano, Nevado del ruiz in 1984 came to life with small scale activity, volcanologists were unable to predict the scale of the event.
- When the final violent event took place after several months of small scale activity, Lahars swept down the valley killing over 20,000 people and resulting in over $6 billion n property damage.
- You can study previous eruption history of a volcano.
- Monitor land swelling
- Gas emissions and the chemical compostion of water.
- Measure seismic activity that are found through shock waves of magma moving towards the surface, expanding cracks and breaking through other areas of the rocks.
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Protection
- In this case this usually means preparing for the event, monitoring the volcano will indeitfy the time and area which is under threat.
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Enviromental impacts of volcanos
- Ecosystems can be damaged or destoryed by flows and fallout of material.
- Acid rain can cause acidification of aquatic ecosytems, killing plants and animals.
- Volcanic gases contribute to the greenhouse effect and add to global warming.
- CLouds of ash and volcanic debris can decrease temperatures and reduce sunlight reaching earth
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Social impacts of volcanos
- People are killed, buildings are destoryed by mudflows, pyrcolcalstic flows, ash fallout and rockfalls.
- Fires can be started.
- Mudflows and flooding from ice melt can cause damage and death.
Montserrat 1997 (DESTRUCTIVE) 19 dead, 100s without homes, 8000 people left after the eruption, poppulation decline.
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Economic impacts of volcanos
- Eruptions can destory businesses and ash clouds can prevent aircraft flying and damage crops. ECONOMIC DAMAGE.
- Expensive to repair damage to buildings
HOWEVER volcanoes can attract toursists.
Montserrat 1997 (DESTRUCTIVE) total loss was around 1 billion, 2/3 of buildings destoryed by Pyroclastic flows. The Port along with schools and hospitals destoryed.
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Political impacts of volcanos
- Damage to agricultural land can cause food shortages, leading to conflcit and political unrest.
- Governments may have to spend money on reprairing damage to buildings and roads, instead of devotion to education and health.
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Preparedness VOLCANO
- Monitoiring increases the notice of volcanic eruptions, meaning warnings can be given out.
- Education on volcanoes in areas of risk so people know what to do if there is a eruption.
- Authorities can stop people entering the area around the volcano.
- Trained response teams and evacuation procedures planned.
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Prevention VOLCANO
They cannot be rpevented, Risk to people can be prevented.
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Mitigation volcano
- Direct inertvention to the volcano, concrete blocks steer lava away from areas at risk.
- Strengthening builiding that are at risk from mudflows and ash pile up.
- Evacuation zones
- Emergency aid on the ready.
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Adaptation volcano
- Capatalise on oppurtunities such as encouraging tourism.
- Move away from at risk areas.
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Mt Nyiragongo 2002, congo IMPACTS
- Lava flows destoryed much of a nearby town.
- 147 people were killed, poisonous gasses, collapse of buildings and lava flows.
- Water and power facitlities destoryed along with the medical facilities.
- Several earthquakes accompanied the eruption.
- Eye irritation and repitory issues from smoke and fumes from the eruption.
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White Island Background 2019
Phreatic eruption, release of steam and volcanic gases.
It was caused by water coming in contact with hot magma as it rose upwards, soil and ash trapped the steam in and allowed pressure to build, eventually it erupted in ash, steam and rock.
Located in New Zealand
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Prepardeness to White Island
GeoNet monitors the volcano, there had been reports of increased earthquake activity, gas release and mud eruptions in the months before.
Three weeks previous the alert level rose from level 1 to level 2
However even closly monitoored volcanoes are unpredictable, however tourists were still allowed onto the island.
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White Island primary impacts
- Rock and ash was launched 3km into the air.
- 18 people were killed and 26 were injured
- However White Island is located around 48km out in the Bay of Plenty so the primary impacts were relatively localised.
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Background of the Iceland eruption 2010
Iceland is positioned on the mid atlantic ridge, seperating the Eurasian plate and the North American plate, on a conservative plate boundary.
Magma fills the magma chamber has the plates move apart through ridge push.
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Preparedness of the Iceland Eruption 2010
In early 2010 seismic sctivity was detected in the area of Eyjafjallajokull, this gave volcanologists evidence that magma was puring from under the crust into the volcanoes magma chamber, a few minor eruptions followed.
However it went quite for a short moment before the main eruption.
1,000 people were evacuated in response to flood risk.
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Primary impacts of Iceland 2010
- Huge amounts of ice melted causing floods
- Large quantaties of ash pured from the volcano, it was picke up by the Jet stream and blown towards europe, this meant that all airspaces were shut costing airlines around £130 million a day.
- Rescuers were forced to wea masks to avoid the toxic clouds of ashes.
- Homes and roads were destoryed and cops damaged.
- No human fataities were incured, risk was relatvely low, only a VEI 4.
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Secondary effects of Iceland 2010
Impacts were felt as far as Kenya where farmers laid off 5000 workers as crops were left to rot at airports.
Kenya exports were down 97%.
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Responses to the Iceland eruption 2010
- European Red Cross mobilised volunteers, staff and resources to aid those directly impacted by the earthquake.
- 600 more people were avcuated in 2 hours, 120 were given accomadation.
- Iceland declared a state of emergency
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Response to Montserrat eruption 1997
- UK provided £17 million in aid
- £41 million in long term aid committed to development of the north of the island.
- Montserrat Volcano Observatory set up to predict in the future.
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Seismic hazards relation to plate tectonics
As the crust of the earth is mobile, there tends to be a slow build up of stress ithin the rocks, when pressure is suddenly released, parts of the surface experience an intense shaking motion.
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Focus
This is the point where this pressure release occurs within the crust.
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Epincentre
This is the point immediately above the focus on the surface of the earth
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Three categories of earthquake
- Shallow focus (0-70km)
- Intermediate focus (70-300km)
- Deep focus (300-700km)
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Distribution of earthquakes
- Vast majority of eathquakes occur along a plate boundary, the most powerful being asscociated with the destructive margins.
- At conservative margins the boundary is market by a fault, movment along causes a earthquake.
- Some earthquakes occur away from boundaries and are associated with the reactivation of old fault lines.
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How they form - Conservative boundary
- At a conservative plate margin, plates can become stuck due to friction, the convection currents in the asthenosphere continue to push, which builds pressure, eventually the plates give way and the jlting motion sends out seismic waves or shock waves through the ground.
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What determines a eathquakes magintude?
1. Margin type, the ;argest earthquakes take place at destructive plate margins, where subduction zones cause huge pressure to build up. Constructive tend to be lower magnitude than conservative and constructive.
2. Depth of focus, deep focus earthquaks tend to hae higher magnitude than shallow fucos earthquaks, however they may have less damage as they have to travel further to reach the surface.
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Magnitude of earthquakes
The magnitude of earthquakes is measured in a variety of ways, the Richter scale is a logarithmic scale, an event measured as a 7 on the scale is 10 times larger than a 6. It measures the height of the largest seismic wave
Moment Magnitude scale is based on total amount of energy released by the earthquake, logarithmic and no uppoer limit.
Mercalli scale measuers impacts as observatiojns of the event, between 1 and 12. 1 is only detectable by instruemnts and 12 is total destruction.
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MMS
Moment magintude scale identifies energy release, its scale is same as the richter, 1-10.
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Mercalli scale
Intensity of the event and its imoacts, it is a 12 point scale where level 11 is approximate to 2 on the richter scale, it goes up to level 12 which is around 8.5 on the rhicter scale.
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Construtive boundary earthquakes
Least severe
Gentle expansion of the plate margin
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Primary impacts of Earthquake
Ground shaking, this is the only primary impact of a earthquake and its severity will depend on the magintude of the earthquake, geological conditions, distance from the epicenter and depth.
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Secondary impacts of earthquakes
- Soil liquefaction
- Landslides/avalanches
- Fires
- Effects on built enviroment
- Tsunamis
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Secondary imapcts of earthquakes - Soil liquefaction
When soil is saturated the vibrations of an earthquake cause it to act like liquid, violent shaking means that they lose their mechanical strength and behave like fluid. Soil becomes weaker and is more likely to subside when it has large wieght on it.
Loses its density and therefore cannot support roads, pipes and houses.
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Secondary imapcts of earthquakes - Landslides and avalanches
Ground shaking results in slope failure, this results in unstable ground.
2015 Nepal eaarthquake caused avalanche that resulted in 19 deaths.
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Secondary imapcts of earthquakes - Fires
Collapased electricy transmission systems can result in broken gas pipes.
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Secondary imapcts of earthquakes - effect on people and built enviroment
- Collapsing buildings, destruction of roads and other forms of communication, destruction of services such as water, gas and electricty provision, disease, food shortage, disruption to local economy.
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Secondary imapcts of earthquakes - Tsunamis
- When an oceanic crust is jolted during an earthquake, water above the plate is displaced, this caused water to travel fast with low amplitude (height), as it gets closer to the coast the sea level decreases and there is friction between the sea bed and waves.
This cases the waves to slow down and gain height, creating a wall of water that on average is 10 feet high.
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Social impacts of Earthquakes
- Buildings collapse is the most dangerous effect of earthquakes, killing and injuring people and trapping them.
- Liquefaction causes gas lines and power lines to break causing fires.
- Water pipes can cause flooding.
- Disease such as cholera can spread
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Enviromental impacts of Earthquakes
- Industrial units including power plants can be damaged by earthquakes and tsunamis , causing leaks and release of radioactive material.
- Fires started by damaged gas and electrcity ines can destroy ecosystems.
- Tsunamis can contaminate and flood fresh water ecosystems, killing plants and animals.
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Economic impacts of earthquakes
- These can destroy business premises through ground shaking and liqeufaction.
- Damage to industry may mean that the country has to rely on expensive imports of goods and energy.
- Expensive repairs to damage to infastructure.
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Tsunami examples
2011 Tohoku Japan
- 15,000 people were killed, 45,000 left homeless.
- The tsunami caused the meltdown three nuclear reactors at the Fukuchima Nuclear power plant, this led to radioactive waste being released into the enviroment.
2004 Boking day Tsunami
- 230,000 deaths.
- 1,500 villages destroyed.
-,In indonesia the countries sensor system was hit by lightning so no alert was sent out.
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Prediction of seismic hazards
- Difficult, regions at risk can be identified through plate tectonics, attempts to predict are very difficult.
- Unusual animal beahviour, releases of gas and groundwater levels or magnetic field levels can help.
- Hazard mapping, geolgical information and studying ground stability in order to predict the imapct of a earthquake.
- Close studies on the fault line could predict where the next earthquake will take place.
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Prevention of earthquakes
- Liquefaction of soils can be prevented through soil stabalisation, gravel columns can be placed into the ground.
- Avalanches can be prevented through controlled explostions.
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Preparedness for earthquakes
- Earthquake prone areas such as Japan have extensive awareness strategies and education place.
- Japanese authorities across the country also regularly conduct widespread earthquake drills in places such as public buildings, schools, and office
- Earquake warning stystems and tsunami warning systems
- Plans, education and training.
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Mitigation of earthquakes
- Search and rescue, immediate emergency aid and evacuation.
- Demolishing older and unsafe buildings, making sure infastruture is built in order to withstand earthquakes.
- Tsunami seas wall and wave breaks.
Japan's sea walls were designed to hold back waves of up to 8 metres, but the 2011 earthquake saw them reach 12 to 15 metres in height.
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Adaptaion of earthquakes
- Move away from at risk areas.
- Capatalise on oppurtunties, such as encoruaging toursim.
- Change lifestyle choices, mving valuable items so they dont fall, and earthquake proof buildings. Place on stilits or raise buildings in order to prevent tsunami damage.
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Storm Hazards
- Sea level can raise by several meters and can serge inland, this can be either a result of high winds or low pressure physically raising the sea level.
- Winds gusting to 250kph.
- High rainfall, flooding. large storm systems, high rates of precipitation, intsntiy of rainfall leads to infiltration excess.
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Mitigation/praperdeness strategies for storm hazards
Seeding
Sea walls
Construction
Key line defence
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Mitigation/praperdeness strategies for storm hazards - Seeding
- Weather modifcation technique
- Seeding with silver iodide reduces the energy released by condensation, BUT only in HICs as very expensive.
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Mitigation/praperdeness strategies for storm hazards - Sea walls
- Prevented storm surges and flooding.
- Through sea walls or cultivating mangrove systems and sandunes.
- Raises the height of the coast line and absorbs energy.
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Mitigation/praperdeness strategies for storm hazards - COnstruction
- Builiding infastructure and houses to resist win and water.
- Florida place their power lines underground in many areas.
- Embankment in order to reduce flooding
- Shut public transport
- Underground infastructure and robust housing
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Mitigation/praperdeness strategies for storm hazards - Key line defence
- Monioriing on sataellites
- Issue national warnings BUT not always accurate PLUS problems with false warning, extra costs and undermine confidence
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Mt Nyiragngo, Congo RESPONSES
- Authorities placed Goma and the surrounding area on red alert, which enabled a full evacuation to take place.
- Prompt reponse argubaly kept the death rate low.
- UN ferried in humanatarian aid 2 days after the eruption.
- UN set up camps to house displaced people
- Cosr of providing relief, food shelter etc. 15 million dollars
- Although cost of rebuiling Gomas infustructure was even greater.
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Turkey 2023
7.8 magintude earthquake struck southern and central turkey.
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Impacts of the earthquake TURKEY
- 50,000 deaths
- 100,000 injured
- 4 million buildings damaged and 160,000 destroyed.
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Prediction and preperation in turkey
- Two signifcant fault lines means turkey is VERY vulnerable and at risk.
- Disaster Law 7269, was passed by the turkish parliament establishing a plan to institute disaster preparedness regulations at national, provincial and municipal levels.
- Earthquake tax was levied after the 1999 desaster and strengthening of the building codes.
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Failures of preperation in turkey
- The President said that 'it was impossible to prepare for the scale of the desaster'
- Regulations and building codes have been ignored in turkey as it adds 20% onto the costs of construction.
- National funds that were meant for disasters were spent on highway construction projects.
- Broken roads, lack of resources and heay equipment meant rescue operations were difficult.
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Haiti 2010 Risk and vulnerability
- Signifcant physical risk, it lies at the juction of the North American and caribbean plates between two fault lines.
- 7 major event recorded since records began.
- Long history of extreme poverty, national debt and poor housing condiitons, mush of the population is dense and live in informal settlement.
- Construction standards are low and they hae no building codes.
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Haiti background
7.0 MMS and a depth of only 13km, poorest country in the western hemisphere. 50 aftershocks measuring 4.5 and greater.
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Haiti effects
- Death toll up to 316,000
- The Haiti government was accused on inflatiing the figure in order to gain more aid from interntioanl communtiies.
- 2.3 million made homesless.
- 30,000 properties destoryed
- Main prison destoryed, 4000 inmates escaped.
- damage to communications infastructure and the education syetm collapes over 1,000 schools destoryed.
- Violence and looting, breakdown in law and order.
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Haiti solutions
- Major relief program was directed towards the disaster, rescuers, reliefe aid agencies and national governments faced difficulties dealing with the aftermath.
- The country had little heavy lifting equipment, hard to carry out rescue operations.
- US government deployed 3,500 soldiers
- 3-4 years after the events the effects are still obvious, by 2014 over 170,000 were still in displacement camps and over 20% of children not in school.
- 70% lacked electritcity
- New building codes have now been establshed.
- Part of the governements debt has been written off.
- Final costs of the event 8 billion
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Tropical storm definition
Tropical storms are intense low-pressure weather systems that develop in the tropics.
They usually measure between 200-700km in diameter and begin in areas of low pressure, resulting from surface heating, into warm air.
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What conditions must be present in order for a tropical storm to form?
- An ocean location with sea temperatures above 27 degrees C, continuous source of heat in order to maintain rising air currents.
- An ocean dept of at least 70m, moisture provides latent heat, rising air causes moisture to be released by condensation.
- 5 degrees north or south of the equator in order that the coriolis force can bring about the maximum rotation of the air.
- Low level convergence of air in the lower atmosphere circulation system, winds have to come together near the center of the low pressure system.
- Wind shear, winds must be present for the swirling motion to form but not too strong so that the storm system does not rip apart before it can form.
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Distribution of tropical storms
- Storms occur between 5 degrees and 20 degrees north and south of the equator. Coriolis force is 0 on the equator, meaning the storm cannot spin.
- Hurricanes are located in the Carribean sea and the gulf of mexico.
- Cyclones form in the bay of bengal
- Typhoons form of south east asia.
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Magnitude of tropical storms
Tropical revolving storms are measured on the saffir-simpson scale, this is a five-point scale that measures storms based on their central pressure, windspeed, storm surge and damage potential.
Scale 5 event must have wind speeds at 250km/h or greater and a storm surge that is 5.5m or greater.
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Primary Impacts - Wind speed
Wind speeds can often exceed 150km/h, high winds can cause structural damage to buildings and roads, bridges etc. they can bring down electrcity transmission lines and devestate agriculture areas. Debris can also directly threaten peoples lives.
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Primary impacts - Storm surges
A storm surge is a large rise in sea level caused by high wind speeds pushing water towards the coast and by the low pressure of the storm.
Hurrican Katrina - New Orleans is a city most below sea level, the complex system of flood defences were breached and 80 percent of the city was flooded. Coastal conservation areas and habitats such as turtle breeding areas were destroyed.
Haiyan - Storm surges measure up to 6 meters. Taclobans city airport was damaged by the storm surge, this was the center of the international relief operation.
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Primary impacts - High rainfall
It is not unkown for rainfall to exceed 300mm, bringing about severe risks of flooding, landlslides and mudslides. If there is high releif near a coastal area rainfall could increase to over 500m/day.
The primary impact of rainfall results in seconday impacts.
Haiyan, heavy rainfall up to nearly 300mm falling in under 12 hours. This triggered landslides where major roads were blocked as a result, meaning response efforts were delayed.
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Vulnerability of tropical storms
- The intensity of the storm.
- Speed of movement, the duration of the storm.
- Distance from the ocean/coastline
- Physical geography of the coastal area, any mountain ranges relative to the coast, width of coastal plains or size of delta.
- Preparations made by the community
- Warnings and response effectiveness.
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Formation of tropical storms
1. Warm, moist air rises, leaving an area of low pressure below, this causes warm are from the surrounding areas of higher pressure to moce into this low pressure area and rise too. Wamr air is constantly tising and accumalating in the atmopshere.
2. When the watm air rises it cools, condensing into clouds. Due to the coriolis effect the whole system is spinning. As energy is added to the system through latent heat is begins to spin faster and generate greater windspeeds.
3. The eye of the storm is in the centre, this is a area of the lowest pressure, cool, dry air. The more intense the storm the clearer the eye.
4. Surrounding the eye is the eyewall, this is the most intesne and powerful area of the storm. Warm and mosit air is rapidly rising here, with extremely high winds and rainfall.
5. The suppy of energy is lost when it reaches land.
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Frequency and regularity of tropical storms
Tropical storms form in the Northern-Hemisphere from June-November and the southern hemisphere from November to April. Majority of tropical storms dont reach land.
They are generally regarded as iregular because although they occur at the same areas their paths tend to be different, the route taken is dependant on the storm and the climatic conditions.
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Secondary impacts of tropical storms - Flooding
Coastal/river flooding from storm surges and heavy rain.
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Primary Enviromental impacts of storms
- Beaches eroded and sand is displaced.
- Coastal habitats such as mangrove forests and coral reefs are destroyed.
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Primary Economic impacts of storms
- Buisness destroyed
- Agirculture land damaged
- Oil installations in the gulf area after Hurricane Katrina were damaged, the price for oil shot up affecting people world wide.
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Seconday enviromental impacts of storms
- River flooding/salt water contamination
- Animals displaced from flooding
- Water sources forced to change course due to blockages.
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Secondary economic impacts of storms
- Rebuilding and insurance payout.
- Sources of income and jobs lost.
- Economic decline as sources of income are destroyed.
KATRINA
- The financial cost of the storm broke all records in the USA, with damage estimated to be around $200 billion.
- The famous french quarter of new orleans was severely damaged, thus reducing tourism revenue.
HAIYAN
- Total damage from the strom was estimateda t around $2.9 billion.
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Political secondary impacts of storms
- Issues paying back international aid
- Pressure for government to do more about global warming.
KATRINA
- Pressure on Bush for being too slow to visit the affected areas and the failures of effective planning and slow response. Most of the effected population were african-american urban dwellers, many blamed the slow response on this factor.
HAIYAN
- Local officials were killed by the storm, local government control collapsed and lotted and chaos was reported.
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Prediction of storm events
- Weather bureaux, such as the NAtional Hurricane centre in Florida, are able to access data from geostationary satellites and from both land and sea based recording centers.
- The USA also monitors tropical storms that have the potential to become hurricanes and threaten people.
EVAL
- High economic cost accociated with evacuation and therefore predictions need to be right. People wont trust evacuation measures if they are wrong, and refuse future advice.
- It is not always possible to give more than 12-18 hours warning as they follow a relatively erratic path, areas with poor commincations suffer.
ESSAY E.G
In 1997 a tropical cyclone warning in the Coxs bazaar area of bangladesh allowed for the evacuation of over 300,000 people. AS a result the death toll remained below 100.
KATRINA
- Evacuation plan was only drawn up 19 hours before the storm hit.
- Much of the Levee system to protect new orleans was poorly constructed and replacement work was only 60% done, the scientifc american magasine described the city as a 'disaster waiting to happen'.
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Prevention of storm events
Like any natural hazard this is very difficult to do, you can prevent secondary effects of the nazard but not the hazard itself.
Having said that cloud seeding could force the cyclone to release more water over the sea and therefore weakening the system as it approaches land.
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Mitigation and adaptation of storm events
- Hurricane and cyclone drills can be carried out in the most vulnerable areas. Project safeside, a hurricane awanreness program that is composed of precuationary drills to be used in schools.
- Search and rescue, immediate emergency aid and evacuation.
- Strengthen the home through door barricades, roof strengthening.
- Clearing loose debris before storms.
- Move away from the area that is at risk.
- Design buildings to withstand high winds and flood damage.
- Flood defenses such as houses on stilits, coastal walls, flood barriers and breakwaters.
ESSAY E.G
- Sea Wall that was built to protect Galveston Texas after a storm surge in 1900 killed 6,000 people.
KATRINA
- Flood defences in new orlean failed, 80% of the city was flooded.
- Much of the Levee system to protect new orleans was poorly constructed and replacement work was only 60% done, the scientifc american magasine described the city as a 'disaster waiting to happen'.
- Response services delivered food and water for 150,000 people for three days.
- Government aid was fast to help recovery, the Senate passed a bill ofering 10.5 billion USD dollars in aid.
- Public donated 1.8 billion USD to the american red cross.
HAIYAN
- Prompt action from WHO and other relief agencies meant that the risk of disease such as Cholera was not a issue.
- UN said that 'access remains a key challenge as some areas are still cut off from relief operations' suvivors as a result where not given access to basics such as food and water
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Hurricane Katrina
In 2005 Hurricane Katrina was measured as a category 5 hurricane. It first developed on 23 august over the Bahamas.
Sustained windspeeds of 280km/h and gusts of up to 345lm/h and a central pressure of 902mb. 5th most intense atalantic basin storm on record.
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Primary social impacts of storms
KATRINA
- More than 1 million people became displaced from their homes
- Of the 180,000 houses in the city of New Orleans, 111,000 were flooded and 55,000 were too badly damaged to repair.
- 5 million people were left without power.
- 1,800 people were killed.
HAIYAN
- 6,000 fatalities, with some esitmates saying it could be up to 10,000.
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Secondary social impacts of storms
- Homelessness
- Polluted water
- Food shortages and damaged land
- Crime
KATRINA
- Looters ransacked the abandoned houses and shops in new orleans, the national guard had to be deployed.
HAIYA
- 2 million people made homeless
- 6 million displaced
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Economic Impacts of KATRINA
- 230 jobs were lost due to damaged businesses.
- 30 oil platofrms in the gulf of mexico were damaged.
- 5300km2 of forest was destoryed in Mississippi, 5 billion lost income from logging.
- TOTAL DAMAGE WAS $300BN
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Typhoon Haiyan (Philippines)
- One of the strongest tropical cyclones every recorded and the deadliest on record in the philippines. It originated from a area of low pressure on the 2nd of november 2013.
- It tracked westward as it intensfied to a category 5 storm with wind speeds reaching 300km/h
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Positives of warning and prediction methods STORMS
- Awareness of the storm and its severity allows people to prepare and evacuate.
- prediction allows to determine the vulnerable areas and therefore evacuation of these specific areas.
- Helpful for large scale evacuations, for example 1.5 million people were evacuated from lousianna before katrina.
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EVALUATION of aid STORMS
Corruption, no garunttee that aid will always reach the place it needs to.
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Evaluation of adaptation STORMS
-Local scale spolutions
- High cost
- Requires political buy in
- Acceptance of the impacts.
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Benfits of insurance STORMS
- Damage prevention.
- Higher costs of living in higher risk areas means that people will be forced to move away towards areas of lower risk.
1980-2014 12 Billion USD were covered due to tropical storms.
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EVAL of insurance STORMS
- Forcing people to move, become dispalced due to high cost premiums can be bad if they have no place to go, or cannot afford to move.
- Conditions of insurance can be difficult and leave people vulnerable, hurrican Katrina.
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Wildfires
A large uncontrolled fire that can occur on a very large scale and cause widespread destruction, killing much wildlife and posing a threat to humans. The nature of the fire depends on a number of conditions.
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Requirements for a Wildfire
- Heat, allowing fir to spread byevaoprating moisture in fuels and allowing them to ignite and travel more easily.
- Oxygen, 16% is required as it supports the oxidation process, creating heat and gases.
- Fuel, gives the fire burnable material allowing it to travel and advance
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Factors that influence wildfires and their spread - Fuel
- Thick close together vegetation allows fires to spread quickly and easily, trees and think bushes lead to more intense wildfires, whereas grassland does not burn as intensely.
- High moisture content will mean that the burning process is much slower, heat from the fire must eliminate the moisture.
- Some plants and trees contains oils and resins that promote combustion.
- Density of fuel influences its flammability.
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Factors that influence wildfires and their spread - Oxygen
- Weather conditions such is wind is a very important factor as it brings a fresh supply of oxygen to the fire and push it towards a new fuel source. The fire will advance much faster when wind speeds are greater.
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Factors that influence wildfires and their spread - Temperature and climate
- Fuels attain their heat by absorbing surrounding solar radiation.
- Temperature of fuel influences its susceptibility to ignition, fuels will ignite more readily at higher temperatures.
- Humidity, the amount of water vapour in the air affects the moisture level on the fuel. At low humidity levels, fuels become dry and burn more quickly than when humidity is high.
- There must be enough rainfall to undergo signifcant plant growth whilst also having considerable dry spells and droughts to dry out the fuel. Areas with both dry and wet seasons, with a high degree of seasonality are partciulary suseptible.
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Factors that influence wildfires and their spread - Larger scale climatic events
- Santa Ana and Diablo winds in california mean more wildifre damage. High pressure systems in the great basin creates clockwise desert winds. As they flow over the Sierras and desert ranges they warm, lose humidity and as a result humidity falls and fuel is dryer. Winds in the are fast and unpredicatble cause fires to be unpredicatble and fast growing.
- El Nino (warm phase) and La Nina (colder phase) have a effect on wildfires. It is though that El Nino provides warmer and wetter seasons to grow vegetation and La Nina creates dryer seasons.
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Factors that influence wildfires and their spread - Topography
- Fires spread much faster on hills as heat rises. ALTHOUGH burning logs can role down hill and cause it to spread in the other direction.
- they can jump across riverss and into areas due to lit debris which can spread.
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Surface fires
These are fuelled by low-lying vegetation such as leaf and timber litter, debris, grass and low-lying shrubbery. They travel slower and are easier to estinguish.
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Ground fires
These fires are fed by subterranean roots, leaf litter and other buried organic matter. These can be particulary susceptible to ignition due to sparks flying of spot fires. They typically burn slowly for days to months via smoldering.
E.G peat fires in Kalimantan indonesia which resulted in the riceland creation project being drained and peat dried.
They are difficult to put out as they are underground and can burn throughout the year if weather conditions allow it to.
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Ladder fires
These consumer material between low-level vegetation and tree canopies, such as small trees, downed logs and vines.
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Crown fires
These burn suspended material at the canopy level such as tall trees, mosses and vines. Ignition is dependant on the density of the suspended material and sifficent surface and ladder fires in order to reach the tree crowns.
These fires burn the entire tree from top to bottom.
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Causes of wildfires HUMAN
Majority of the time caused by human activity.
- Arson, discarded cigarettes, discarded glass and plastic magnifying the suns solar radiation, sparks from equipment such as telephone lines and power lines.
- Poorly managed slash and burn clearing.
- Forests cleared through logging encoruages the dominace of flammable greasses, abandoned logging roads overgrown with vegetation could act as corridors.
In the USA 6 times the number of wildfires caused by human means such as campfires and controlled burns than by natural means.
2018 CAMP FIRE investigatros blamed the cause of the fire to sparking from power lines, and a result of urban sprawl in california and increasing infastructure coming in contact with vegetation.
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Causes of Wildfire PHYSICAL
- Volcanic eruption
- Sparks from rockfall
- Spontaneous comnustion
- Lightning
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Distribution of wildfires
These are a rural hazard and can occur in most enviroments that provide, heat, fuel and oxygen. Areas that are most susceptible are those with a combination of dry vegetation and lightning strikes. Areas with a dry season, suseptible to drought AND signifcant vegetation are most effected.
- Parts of Australia
- USA and Canada
- Southern Europe, south of france, italy, greece, turkey and mediterranean islands.
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Factors that influence wildfires and their spread - Human factors
- In the LA basin houses are built in low density with each other, this allows for natural vegetation to grow between houses, helping the spread of wildfires and putting a large number of properties and people at risk.
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Primary impacts of wildfires - Loss of crops, timber and livestock
- Forest fires can have a huge impact in timber producing areas with the loss of trees that will take many years to replace. In the USA it has been estimated that over $10 million per day is spent fighting such fires.
Victoria 2009
- Loss of livestock, around 12,000 cheep, cattle and horses. Grain, hay, pasture, fruit, trees and vines. Lost thousands of km of timber.
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Primary impacts of wildfires - Loss of life
- Fires are events that can be more easily evacuated than other hazards. Some fires develop quickly without signifcant prior warning and people can become trapped.
CAMP FIRE 2018
- 85 people were killed by the fire and 17 were injured.
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Primary impacts of wildfires - Loss of property
- Urban expansion has meand that more communities are at risk from wildfires, fringes of large towns and cities are now at risk. Large numbers of people can be left homeless.
CAMP FIRE 2018
- The community of Concow and the town of paradise were destroyed within the first six hours of the fire, losing an estimated 95% of their buildings and infastructure.
- Around 19,000 buildings were destroyed.
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Primary impacts of wildfires - Release of toxic gases and particulates
- The southeast Asia 'Haze' is a fire related large scale air pollution that occures regulary in many areas of the region.
- Resulting pollution covers a large number of countries in the region includin singapore, malaysia and thialand.
- POLITICAL tension as governments of these countries have demanded the indonesian government takes measures against this and prevents companies responsible for slash and burn techniques and forest fires.
CAMP FIRE 2018
- Smoke from the fire resulted in wide spread air pollution issues on a larger scale, throughout the San Francisco Bay area and the central valley, this caused the closure of many schools and caused a number of health issues.
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Primary impacts of wildfires - Enviromental
- In indonesia the fires of 1997 destroyed the Wein river orangutan sanctuary.
- Air pollution from ash, water pollution and habitats destroyed.
- CO2 emission from fire, GLOBAL SCALE
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Secondary effects of wildfires - Evacuation
- Many people are forced to flee from the area of the fire, such people will not be allowed back into the effected area for long periods of time, if not forever. Emergency shelters and accomodation will have to be created.
CAMP FIRE 2018
- In May 2019 it was reported that more than 1,000 families who were displaced by the fire were still without homes 6 months later.m
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Primary impacts of wildfires - Increased flood risk
In certain enviroments where rain comes in heavy bursts the loss of signficant vegetation and the consequences of decreasing interception may lead to increased flooding.
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Primary imapcts of wildfires - economic
- Businesses destoyed in the fire
- Economic costs of fighting fires, equipment, infastructure, water.
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Prevention and Preparedness WILDFIRES - Education
- Wildifres overaal will never be eradicated entierly, howeveer public awareness can prevent ignition and prepare people for wildfires.
- Smokey Bear is a 70 year old US mascot used to provide information to prevent wildfires, make people aware of the risks.
- Education on the risk, evacuation plans, emergency service drills and training.
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Prevention and Preparedness WILDFIRES - Warning systems
Broadcasted weather warnings, commonly reffered to as red flag warnings warn people when the perfect conditions for wildfires are occuring. This means people may wish to evacuate or place campfire bans.
2018 CAMP FIRE
- Immediate response was slow, there was communication difficulties as the wildfire alert system had been damaged at cell towers, some residents received no warnings.
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Prevention and Preparedness WILDFIRES - Prediction
- Thermal infrared satellite imagery shows where wildfires are occuring so that people can stay away from these areas. Also authorities can quicjly located wilfires and begin evacuation.
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Mitigation of wildfires
To mitigate the effects of wildfires the fire must be diverted or extinguished. Immediate responses are mainly concerned with protecting those directly at risk through estinquishing the fire.
They can also consist on long term mitigation strategies that work to reduce the impacts before they occur
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Mitigation of wildfires - Controlled burnings
This aims to get rid of much of the litter and other flammable materials to less fuel is available, they are strictly moderated.
Creating gaps in trees called fire breaks also limits the spread.
EVAL
- If control lines are too narrow than fire can jump by their crowns.
- Time and labour intensive, requires constant upkeep to clear accumuating fuel.
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Mitigation of wildfires - Managing the built enviroment
This is done by increasing the gap between houses and vegetation by incperating more firresetatn methods of construction such as more stone and brick rather than wood.
Furthermore taking measures such as trimming tree limbs near houses, keeping roofs, gutter and decks clear of leaves etc.
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Adapting to wildfires
Many who live in fire prone areas must adapt to how they liver through insurance. Covering any costs and damage that might be caused by fires.
Modeling can predict who is going to be most vulnerable and therefore who needs to be evacuated.
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Long term responses to wildfires
- Replanting trees, particulary in commercial forestry areas in order to improve the economy that has been devestated by the fire.
- After vegetation has been remobed by fire there is greater danger from flash flooding and mudslides on what are now unprotected slopes. Planting trees can stabalise the slopes and prevent flooding.
- Makes sure people are better prepared for the next fire, mitigation strategies in response, getting emergency supplies ready, education, evacuation routes.
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Mitigation of wildifres - Fire engines
- Firefighting equipment using water, foam and chemicals to suppress outbreaks. The engines are able to carry up to 3000l of water, and are adapted for off-road use.
- They can support firefights away from water infastructre and supress the spread of the fire.
EVAL
Small scale, requires a large and coordinated fleet to supress larger fires, this is expensive.
Difficult to access remote areas without roads or control lines
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Mitigation of wildifres - Smokejumpers
- Firefights who parachute directly into wildfires, carrying fire axes and fire-retardant gel. They bring up to 3 days worth of rations to work away from support.
- Allows for suppresion and construction of fire breaks in remote areas
EVAL
- Small scale
- High risk to personal health including smoke inhalation burns.
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Mitigation of wildifres - Aerial support
- Aeroplanes and helicopters release water and fire-retardant chemicals directly on to the wildfire from above.
- Can supress fires over a large scale and area, can access remote areas.
EVAL
- Expensive to support and run, risk to pilots. 21% of wildlife fighting fatalities were in arial accidnets. Fire supressing chemicals can be toxic causing harm to landscape post fire.
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Mitigation of wilfires - Hazard Mapping
GIS is used to identify areas at risk of wildfire, considering climate, drought risk, fuel loading and topography.
This is used to forecast the likelihood of a fire in real time, and inform land use planning and insurance.
- Large scale, informs evacuation procedure and can help reduce the number of people living at risk when used for insurance.
EVAL
- Requires effective implementation of the data – short-term economic and political pressure may prevent this.
- Burn sites after the 2018 Camp Fire in California contain more buildings five years after fire than they did before.
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Mitigation of wildfires - Ecuation and Volunteering
Informing people of common triggers of wildfires and how to prevent them may reduce wildfire frequency.
Evacuation training and alerts inform the public of how to react in case of wildfire.
- Aims to reduce the leading cause of wildfires, reducing panic in the event of a fire and can prevent the spread of fires if land is managed well.
EVAL
Requires freqeuent updates to ensure individuals no how to react.
Difficult to police campfires
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2018 Camp fire, Northern California
On 8 November 2018, strong north easterly winds interacting with a failing electrical transmission tower ignited a wildfire under power lines to the northeast of Paradise, California.
Over the next 5 days, the fire burned 153,000 acres, destroyed nearly 20,000 structures, killed 85 people.
Resulting in around 17 Billion USD in total damages
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Causes of the 2018 camp fire
- The fire was initially fuelled by grass amid sparse pine and oak woodlands.
- Low humidity and high wind speeds drove the fire, there had not been signficant precipitation for around 200 days prior to the event and a state wide drought in califonia had previously been announced.
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2018 Camp fire - evacuation issues
Evacuation routes became clogged and civilians and responders became trapped in the wildfire and were therefore placed at risk. Hundreds were trapped deep within the town, cut of by flames, communication failures and clogged evacuation routes.
A LA times investigation found that local towns such as paradies ignored repeated warnings of the risk to its residents and crafted no plan of evacuation. Historical records showed that wind driven firestroms were very possible and the area was at high risk.
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Multi Hazard Enviroment
These are areas where the poppulation is at risk from too or more natural hazards.
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MHE CASE STUDY - Haiti
Haiti is vulnerable from experiencing both earthquakes, tsunamis and tropical storms. For this reason it is a multi-hazardous enviroment.
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MHE CASE STUDY - Physical geography, why is Haiti a MHE?
- Enriquillo plantain garden fault runs along the southern side of the island Hispaniola, and close the capital of Haiti. In 2010 pressure release resulted in a 7.0 magnitude earthquake.
- Haiti is also located near the Atlantic basin and in the tropics where Ocean temperatures are high enough and tropical stroms are very common. Low pressure agressive hurricans such as Category 5 storm Mathew in 2016 increase the risk.
- Heavy rainfall from tropical storms combined with the mountanous topography of Haiti and limestone geology create the ideal conditions for landslides. They can also be triggered by earthquakes.
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MHE CASE STUDY - Why is the Haiti Poppulation at so much risk?
- Dense poppulation, 3.5 million people were driectly effected by the 2010 earthquake. This led to particulary bad impacts. In 2010 316,000 people were killed and 1.6 million people were left homeless.
- Economic damage from 1 hazard stunts development and growth, therefore making it very difficult to mitgate, prepare and predict future hazards and their impact. 2010 earthquake caused a 5.1% contraction in the economy and caused damages of 8.5 Billion USD.
- It is estimated that Hazards have set the country back around 125 years in terms of economic development.
- With a population of 10 million, Haiti is overpopulated; of these 1 million live in the capital. Rapid population growth due to rural–urban migration (rural areas are poorly developed and isolated, due to low levels of investment, low GDP and debt) meant that Port-au-Prince grew too quickly for any form of urban planning to be implemented.
- The country’s small GDP is spent on constant processes of reaction to and rebuilding because of natural disasters, and not on improving social development.
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MHE Case study - Impacts of Mathew 2016
- Hurricane mathew was a category 4 storm with winds reaching 140mph and pressure as low as 949mb. The death toll in haiti could have been above 1600.
- The UN estimated the total damage of the hurricane to be upwards of $10 Billion, and over $2 billion for haiti.
- The Hazard resulted in further flooding and landslides.
- Extensive destruction to infastructure and up to 90% of crops and livestock was lost in some areas.
- 450,000 children were forced out of school and there was a sharp increase in the number of CHolera cases.
- It was a major setback for Haiti as they were just beginning the rebuild from the 2010 earthquake. Destruction of infastructure set the country further back in terms of economic and social development.
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MHE Case study - Other tropical storms
- Hurrican sandy in 2012 hit right during recovery of the 2010 earthquake, millions were in informal settlement, in high density areas without homes. Death and homelessness far outstripped the effects in New York and due to a lack of media coverage Haiti recieved little attention and aid.
- Before the 2010 earthquake Haiti suffered a number of hurricanes in 2008 such as Gustav, hannah and Ike. they all brough hevay winds and rain. 800,000 people were left in need of humanitarian aid and 331 were dead.
- In 2010 6 months after the major eathquake haiti was hit by Hurrican Thomas on the west coast, winds reached 140mph and there was severe rainfall. 100,000 people were effected, water was contaminated and there was severe flooding, hindering the rebuilding efforts of the earthquake.
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MHE Case study - Impacts of the 2010 Earthquake
- Due to rapid urbanisation 3 million people were living in a overpoppulated Port-au-prince, this is where the epicenter was and over 3.5 million people were directly effected by the hazard.
- Estimated death toll was around 316,000 and over 300,000 more were injured and 1.6 million people were left homless and forced in rescue camps that were wet up by the UN and other charity organisations.
- 105,000 houses destoryed.
- Landslides caused a 3m high tsunami on the coast that claimed three lines and caused further damage.
- Damage to the Haiti economy was around 8.5 billion USD and the haiti economy contracted by 5.1%.
- In 2018 over 1.5 million people were still lving in regugee camps, and tropical storms have hightened issues of disease and flooding in these camps.
- Rebuilded buildings have been again reduced to ruble after the 2012 and 2016 storms.
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MHE Case study - International response
- The majority of money donated has been by the global public and due to a lack of media coverage of some recent events, it has been deemed too little. HURRICANE SANDY
- The UN donated 21 million USD to the refugee and cholera crisis in 2015.
- Haitis international dept was canceled by donor countries in early 2010, but has since risen to about $400 million.
- Separately, the charity Architects for Humanity has set up the Haiti Rebuilding Centre in Port-auPrince. It intends to rebuild communications, centres of education, hospitals and housing that will be planned and constructed to reduce the impacts of future earthquakes with monetary aid from governments and NGOs.
- International health partnership has been sending doctors and nurses to Haiti since 2010.
- A UN peacekeeping force of 9,000 has been in Haiti ever since the 2010 earthquake. However, there have still been reports of disease, murder, civil unrest and rape in refugee camps.
- Responses have been mainly uncoordinated and in relation to other countries minimal
- Financial aid in Haiiti is criticised as it is believed to be laundered back into the bank accounts of business men in the donor countries, it is estimated that around 80% of aid since 2010 has been used in this way.
- The red cross was accused of not spending much of the $500 million it collected for the earthquake.
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MHE Case study - Cholera epidemic 2010-2017
- The UN declared it the worst epidemic of Cholera in recent history and in January 2015 nearly 9,000 people had died in 5 years.
- The outbreak was attributed to infected UN peacekkeepers from Nepal and fractured sewage piples in 2010 hurricane thomas contaminated water flowed out of a UN camp and infected the poppulation.
- Cholera and poor living conditions make for a weak working population. Production and exports slow, and GDP falls. This makes it all the more difficult for Haiti to respond to natural disasters, let alone develop.
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MHE Case study - How poor is Haiti?
- The poorest country in latin America and the Caribbean refion.
- Gni per capita of only 1,420 USD, the loest in the region.
- On the UN Human development index, Haiti ranked 163 out of 191 countries in 2021.
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Primary impacts of the earthquake
- 50,000 deaths
