management of tectonic disasters Flashcards
what makes a disaster a mega disaster? (4 things)
disasters are considered mega- disasters based on these characteristics:
- usually large- scale on either an aerial/ spatial scale or in terms of economic and/or human impact
- their scale causes problems for effective management to minimise the impact of the disaster
- scale may also mean communities and gov. often need international support (short and long term)
- these disasters can affect more than one country (directly or indirectly)
Eyjafjallajokull 2010
considered a megadisaster because:
- huge international effects (SCALE- social and economic) affected a large number of people- disrupting many lives and trade was also halted. the ash cloud that was a reuslt of the eruption spread to large sections of European flight paths forcing the airspace to be closed down. over 100,000 flights were cancelled over 8 days (long duration!)
- economic impact affected numerous countries: airline companies lost large sums of money
- even in Kenya workers lost jobs due to fresh produce, eg flowers, fruit and veg, perishing unable to be flown over to European supermarkets. estimated that in total African countries may have lost $65 million because of airspace shutdown
- drop in tourist numbers affected Icelands economy and at teh time Iceland was experiencing extreme banking troubles due to collapse of its banking system.
Japan 2011
considered a megadisaster because:
- 16,000 deaths across twenty prefecture and 700,000 building damge (large scale)
- duration of the nuclear disaster and the economic losses that came with this (enviro impacts as well)
- most expensive natural disatser in world history (est. cost was 235 billion dollars) (huge economical)
- nuclear disaster resulted in significant changes to Japans energy sources between 2010- 2013: fossil fuels became much more prominent which was far more expensive as these had to be imported in and also had negative impacts on the environment. now new nuclear reactors are more expensive because of additional safety measures required.
- globally, the public acceptibility rate of nuclear power reduced as a result of the accident (led countries, eg Germany, to immediately shut down some of their nuclear reactors)
- GDP decreased by 5% and there were knock on effects for TNCs such as Toyota and Sony which were forced to halt production ( also because of the JIT business model.)
what is a multiple- hazard zone?
they are places where a number of physial hazards combine to create an increased level of risk for the country and its population which is heightened if the country’s population is vulnerable. they are often called disaster hotspots.
often countries can suffer from hydrometeorological and tectonic events and the effects of this can be devastating. hydrometeorological events can occur a lot more frequently which leaves a small amount of time for a country to deal with the previous disaster before a new one hitting. This restricts the ability to fully recover therefore draining resources. EG the Phillippines was struck by three natural disasters within three months in 2013. an earthquake followed by typhoon followed by floods from a tropical depression left the government and aid agencies in a constant state of emergency.
development in countries like this is therefore limited as all the countries money and time is spent on trying to recover from these disasters. a country that is less developed often has poor infrasture and fast growing populations which makes them vulnreable and therefore more at risk. it is a viscious cycle for countires existing in multiple hazard zones.
factors affecting prediction and forecasting
type of tectonic hazard
- volcanoes are far more accuratley predicted than earthquakes. tsunamis cannot be predicted but they can be forecasted through things like the Indian ocean buoy. scientists are trying to improve the predictabilty of earthquakes through changes in radon emissions and electromagnetic ariation but this is with very limited success.
level of infrastructure
- often the success of prediction can be based on the level of infrastructure. if there are no warning systems in place, the message of prediction cannot be quickly spread and the prediction may as well not be there at all if the people in danger do not know about it (they cannot get to safety). time is also a key aspect in warning systems. eg in Japan 2011 tsunami warning systems went out but they left very little time for people to get to safety before the tsunami hit.
location
- remote locations often go unmonitored and therefore are not able to predict volcanoes or forecast tsumanis.
- location can also refer to level of development. developing countries often do not have the funds to invest in warning systems and technology that would enable more successful methods of prediction and forecasting.
hazard management cycle
governments and organisations use this process as a way of protecting people. the aim being to avoid/ reduce loss of life/ property, provide help to those affected, ensure rapid and effctive recovery.
involves four stages
1. mitigation (prevention)
- identifies pot. hazards and works to reduce their impact. aim is to reduce loss of life and property through reducing levels of vulnerability
eg: land- use zoning, developing & enforcing building codes, building protective structures.
2. preparedness
- minimising loss of life and property. facilitates the response and recovery phases.
eg: preparedness plans, early warning systems, evacuation routes increasing aid equipment, raising
public awareness (educating)
3. response
- coping with the disaster. main aims are saving lives, protecting property, make affected areas safe
and reduce economic losses
eg: search and rescue efforts, evacuating people, restoring critical infrastructure, continuation of critical
law services (medical care and law enforcement)
4. recovery
(short term!) - focuses on peoples immediate needs: overlaps with response phase.
eg: essential health and safety services, restoring power and water, re-establishing transport
routes, providing food and temp. shelter, organising financial support.
(long term!) - invloves same actions but may take months/ years: overlaps with mitigation (then cycle cont)
eg: rebuilding homes and other, repairing and rebuilding infrastructure, reopening businesses
and schools.
It is arguable that no stage is more important than the other, they all overlap and rely upon one another in order to successfully reudce impact of hazards. eg making buildings more earthquake resistant (mitigation) will reduce problems in responding and recoverig from earthquakes.
what is Park’s model?
the model (hazard- response curve) shows how and how fast a country or region repsonds after a hazard event. helps to better understand the time dimensions of resilience (from the hazard striking -> country/ place returning to normal). can be used to compare how different levels of development recover from a hazrd event.
along the x axis there are 4 time frames:
pre- disaster
relief (hours- days)
rehabilitation (days- weeks)
reconstruction (weeks- years)
the words along the y- axis describe the quality of life, stability and infrastructure.
wealthier countires have very diff. curves than developing countries as they are able to recover mcuh faster due to higher levels of the y axis contributing to a quicker return back to normality or even an improvement. in hazard events that affect a no. of countries (eg 2004 Indian Ocean Tsunami) each country has its own curve.
the model is useful as it can be used to help plan and understand risk and resilience as well as to prepare better for future events based on the failures/ successes of previous events. Although the Park Model is good to visually compare it is not good at showing qualitive data making comparisons somewhat problematic as it does not show number of deaths,homes destroyed etc. Also Park Model doesn’t take into account spatial variation meaning that it assumes that all areas of a country recover at the same rate. Little attention is paid to preparation and mitigation.
strategies to modify tectonic event
- land-use zoning
- diverting lava flows
- GIS mapping
- hazard-resistant design
hazard resistant design
- the designing and constructing of buildings that can withstand hazards.
engineers study impacts of tectonic events on structure and then develop ways to make them safer. there are numerous ways that this can be achieved.
for earthquakes:
- can be designed to withstand groundshaking eg interlocking steel frames, rubber shock
absorbers between foundations, rolling weights on roof to counteract shock waves.
for tsunamis:
- can be elavted and have anchored foundations
- protective structures built eg sea walls OR research shows that replanting of coasts may
be an affordable way of better protection and therefore modification of an event.
for volcanoes:
- roofs of houses can be sloped near to volcano to reduce amount of ash build up: stops
roof from collapsing - buildings can also be retrofitted for protection eg strengthening existing foundations. not all hazard- resistant design needs to be expensive. eg in Pakistan, some houses have been built from bales of straw and held together by strong plastic netting then covered in plaster. during an earthquake, these walls crack but don’t collapse.
collapsing buildings are one of main cuases of death and damage from tectonic hazrads so this is extremely effective and saves lives. often requires technology and highly qualified engineers but not always (see above)
diverting lava flows and GIS mapping
- building barriers and digging channels in an attempt to divert flows into safer direction.
has resulted in some successes (barriers and channels diverted 1983 Mt Etna eruption in Italy) but the path taken by lava is unpredictable and factors such as the terrain type angle of slope has to be suitable. also stopping the lava flow doesn’t really stop it, it just pushes it somehwere else which could still be dangerous for other communities. - can be used in all stages of hazard management cycle: can identify where evactuation routes should be placed (prepare stage) , can help with rescue and recovery options.
eg GIS mapping in 2015 Nepal earthquake allowed workers to see areas affected and locations of airports which enabled them to support those affected areas and tell aircrafts carrying emergency supplies where to land.
land-use zoning
- process where local government planners regulate how land in a community may be used. hazard maps are used to determine apporopriate use of land and safe evactuation routes. eg areas at risk in land surrounding Mt Taranki are divided into zones based on the likely type and level of damage from eruption.
if an area is deemed at high risk of tsunamis and volcanoes: (not earthquakes)- settlements tend to be limited (or not allowed at all)
- certain building types banned eg nuclear power plants/ hospitals etc.
- communities may be resettled (eg if living on coast at risk of tsunami, population will be moved inland)
- development of areas that provide natural protection limited: mangroves etc.
however not as effective in developing countries- is costly, many poor countries cannot afford it and lack the government management skills. also can be incorrect! in Japan, sediment cores were used to determine the extent of tsunamis in the past to determine what areas would be safe to build on. however they were only 60% accurate as they thought that were the sand stopped the tsunami went no further but this is not rue and resulted in catastrophe. an airport was built on an area though to be safe but actually is at high risk.
strategies to modify vulnrebility and resilience
in order to modify vulnerabilityand increase resilience: prediction and warning, community preparedness, education to change behaviour and prevent hazards from turning into disasters.
- high tech monitoring
- crisis mapping
- modelling hazard impact
- public education
examples of high tech monitoring
eg - GIS: helps create hazard maps and maanage more effectively
- early warning systems: detects signs of a tectonic hazard
- satellite- communication tech: transmits data from monitoring equipment so that early warnings can be issued. eg Indian Ocean Tsunami warning system: data collected from sea floor transmitted via satellite ground stations every 15s
- mobile phones: communicates these early warnings rapidly and can co-ordinate prep activities. eg Japan 2011 when P waves detected, warning texts were sent out.
high tech is effective but relies heavily upon other management factors (eg level of government)
crisis mapping
uses crowd sourced info, satellite imagery and other maps to accurately map out areas stuck by disaster. aid agencies are beginning to use crisis mapping before a disaster in order to improve preparedness by pre-mapping vulnerable areas.
- 2010 Haiti: due to lack of infrastructure and communication after earthquake, local people took action and began providing info for worker eg where food was needed and this was placed on an online map- aid workers quickly began using these. crisis mapping provides sense of order and planning in countries where governence is poor.
what are hazard impact models
computer models allow prediction of impacts of hazrds. this info is fed on computer systems which model effects of a disaster. successful example: forecasted depth of flooding from a tsunami.
- they allow scientists to compare effects of diff scenarios: eg effects of tsunami on communities with a sea wall vs without. this enables scientists to see how effective certain strategies are compared to others and then can develop plans to reduce impacts and target resources more efficiently.
- however a lot of cases are dependant on other varying factors (eg levels of development, location etc) so hard to compare.
