Hazards 4- Future resilience and adaptation

Question 1

Key points about trends in geophysical hazards

Answer 1

-Hydro-meteorological hazards ( floods, storms, cyclones, droughts) have all become more common – possible link to climate change & deforestation.

-The frequency of tectonic hazards has remained static.

-Landslides have increased over time.

-The number of people affected by tectonic disasters has increased.

Question 2

Trends in earthquakes (since 1980)

Answer 2

-No. of disasters has been 15-40 per year.

-Deaths have been variable, with some large events in some years.

-Mega disasters in 2004 ( Bande Aceh Tsunami) & 2010 ( Haiti earthquake) resulted in huge deaths – over 200,000 each.

-Economic losses have increased – more to lose as affluence increases.

Question 3

Trends in volcanic eruptions (since 1980)

Answer 3

-The number of disasters is lower than earthquakes, and deaths are much lower.

-Only 7 eruptions have killed more than 100 people.

-Wider impacts can be great as large-scale evacuation is needed.

-If you look back in history it appears volcanoes & earthquakes are occurring more frequently, they aren’t. It is just they are now better monitored and recorded.

Question 4

Reasons for the upwards trend in the number of disasters since 1960 (peak around 2000)

Answer 4

-Population increase- more people affected

-Urbanization rates high- more people in a small area

-Widespread poverty- people living in risky areas in insecure housing

-More expensive construction and belongings, increasing the cost of damage

-Inequality- increased risk for those lacking access to information and services

-Climate change- increasing the severity of climate, weather, river, and biological hazards

-Environmental degradation- reducing protection from natural systems

-More reporting- information through media

Question 5

Graph showing disaster trends and influences on trends since 1960

Answer 5

Question 6

Table showing the factors to consider when identifying and interpreting complex trends

Answer 6

Question 7

More reasons for the varying impacts of disasters over time

Answer 7

-HICs have seen a decrease in the number of disaster-related deaths due to improved preparation & prediction. LICs have experienced little change, as lack the capital to make adjustments.

-Economic losses mainly in developed countries.

-It has been suggested that increased human activity has affected both the frequency & intensity of disasters e.g. Earthquakes can be triggered by human processes, such as mining & fracking e.g. UK.

-Earthquakes have caused an increasing number of deaths over time. This is largely due to the increasing number of people living in seismic areas which have increased 93% in 40yrs. Tsunamis affect large coastal areas in many regions.

-Predicted by 2050 – 3bn people will live in slums in dangerous locations.

Question 8

Diagram showing the cycle of disaster and management strategies

Answer 8

Question 9

Technology as a geophysical hazard adaptation

Answer 9

Examples: Smartphone apps related to advanced warning. Using GIS images to see creates maps to show where movement was greatest.
See examples in table below & in diagram on right.

Benefits: Warnings/evacuations can save lives.

Issues: Costly, mainly found in HICs/NEES. Possibility of cry wolf syndrome, property is still damaged.

Question 10

Earthquakes- methods of predicting and forecasting

Answer 10

-Predicting the timing of earthquakes has so far proven impossible.

-There is some evidence that animals and birds sense danger before humans, but only just before the seismic waves reach a location.

-Modern seismic monitoring and communications allow for warnings to be given up to a minute before the shockwaves arrive (e.g. Japan).

-Foreshocks can be an indication of a larger event, but the pattern is not certain until afterward.

-The absence of earthquakes along a known fault is cause for concern as it shows that stress and strain are building up (e.g. San Andreas fault), instead of being released by smaller earthquakes.

-Earthquakes may travel along a fault line over time (e.g. Anatolian fault), so it is possible to say which part of the fault will move next (but not when).

-Some faults are unknown (e.g. Christchurch), and earthquakes are surprises.

Question 11

Volcanoes- methods of predicting and forecasting

Answer 11

-Volcanoes have a fixed location, allowing constant monitoring. However, constant monitoring requires technology and is expensive, which is why so many volcanoes in developing countries are not monitored.

-Geological evidence of past eruptions provides clues about the type and extent of future eruptions.

-Measurements include gas emissions (e.g. SO2), harmonic tremors, building of the volcano flanks, and composition of magma. There are usually changes in these readings before an eruption, which allows relatively accurate predictions and warnings to be given, although the exact magnitude is more difficult to forecast.

Question 12

Tsunamis- methods of predicting and forecasting

Answer 12

-Any sub-marine earthquake may create a tsunami, especially if it is of large magnitude on subduction zones with megathrusts.

-Warning systems exist in the Pacific and now also in the Indian Ocean (after 2004), based on seismograph readings locating epicenters and buoys monitoring the movement of the sea.

-Computer modeling (e.g. SIFT), has been used to predict arrival times and wave height, but it does not always accurately account for ocean depth or the shape of the seafloor.

Question 13

Examples of land use zoning

Answer 13

-Prevention of building on low-lying coasts ( tsunamis).

-Avoid areas too close to volcanoes.

-Avoid areas where liquefaction is likely.

-Avoid the base of rock faces where debris & rocks might slide.

Question 14

Benefits and issues of land use zoning

Answer 14

Benefits:
-Low cost
-Relocates people & infrastructure away from areas of high risk.

Issues:
-Prevents economic development in some coastal areas.
-Requires strict law enforcement.

Question 15

Place examples of land use zoning

Answer 15

-Mt Etna, Italy – Hazard zones maps forecast biggest dangers. The greatest risk is above 1000m, on the flanks volcano, so no settlements are allowed in this area.

-Mocoa, Columbia – They have now carried out hazard mapping of landslide risk. The policy encourages relocation, but how do you relocate a population of 56,000 which is growing rapidly?

-Christchurch, NZ – In 1995 potential for liquefaction had been mapped. Had identified parts of the city built on silt, which had a high water table. Should have placed closer attention to this map when carrying out urban planning.

-Istanbul, Turkey – Hazard mapping can help authorities adapt. 30-70% chance of a mag 7 earthquake. Improved seismic design of airport and rail network in 2012. Buildings need to meet criteria or be demolished ( 6.5mn in the next 20 years). Progress slow.

Question 16

Increasing preparedness: examples, benefits and issues, place examples

Answer 16

Examples:
-Earthquake kits ( essential household supplies – water, food, battery-powered radio, blankets) kept in a safe place at home.
-Preparation days
-Risk education
-Household adjustments – nail furniture, install ‘smart meters’ which cut off gas & prevent fires.

Benefits:
-Low cost – can be organized by NGOs.
-Can save lives at a local scale.

Issues:
-Property still damaged.
-Harder to implement in isolated rural areas.

Example:
-Great Californian Shake Out Campaign (Annually on 3rd Thursday in October) In 2019 – 6.5mn participants.

Question 17

Insurance: benefits and issues, place examples

Answer 17

Benefits:
-Allows for economic recovery.
-Some companies require buildings to meet safety codes.
-May provide temporary accommodation after the event.

Issues:
-Does not save lives.
-Few people in developing countries can afford it.
-Insurance companies charge according to the degree of risk posed by a hazard and in areas of very high risk insurance may not be available.
-People might not perceive there to be a risk e.g. only 10% of Californians are insured, even though 10,000 earthquakes occur every year.

Question 18

Examples of geophysical hazard adaptation

Answer 18

-Increased government planning (land-use zoning)

-Personal resilience (increased preparedness, use of insurance, adoption of new technology)

Question 19

Mitigation definition

Answer 19

Refers to pre-event planning and may include fault and geology mapping, hazard mapping e.g. liquefaction risk, landslide risk, land use zoning, early warning systems, seismic design and infrastructure defenses, lava diversion, and preparation.

Question 20

Pre-event management strategies for landslides (+ costs and benefits)

Answer 20

-Land use zoning
-Banning logging on steep slopes/ planting trees
-Improving drainage/diverting water - remove water from the slope altogether and prevent shear force from building up through pore-water pressure.
-Restraining structures e.g. gabions/walls – provides additional shear strength by building support at the base of the slope.
-Netting/rock traps
-Increase slope stability by terracing, therefore reducing the slope angle and preventing damage to a settlement.
-Piling -involves drilling supporting rods into the slope to provide increased stability.

Small scale:
-Mesh curtains - A flexible wire mesh is placed over the slope. This prevents small rock falls from causing damage or harm
-Bench steps - These act as steps in the slope and provide protection against rockfall. Some argue they are ugly and look very artificial.
-Soil nails - This involves drilling steel bars into the slope to provide stability through the strata.
-Soil grillage - This technique involves integrating metal grids into the slope to provide extra stability. It’s cost-effective and can be integrated with more natural landscaping and trees.

Question 21

Describe two ways in which a slope can be stabilized to reduce the risk of mass movement

Answer 21

1) Drilling soil nails into a slope
-Steel nails are inserted into a slope via pre-drilled holes.
-The nails reinforce a slope, especially when there is limited spacing between the nails.
-Inclined nails experience less displacement than horizontal nails when seismic activity occurs.

2) Installing rockfall netting
-Heavy galvanized steel netting is draped over a rockface.
-Passive rockfall netting is designed to control falling rocks that are guided to a collection point at the bottom of a slope.
-Active rockfall netting will not allow rocks to fall and the tense netting will secure a rockface.

Question 22

Diagrams of landslide management strategies

Answer 22

Question 23

Diagram of strategies to stabilize buildings against earthquakes (HICs)

Answer 23

Question 24

Diagram of methods to stabilize buildings in LICs

Answer 24

Question 25

It is important that buildings are ___ to stay protected against earthquakes

Answer 25

Ductile

Refers to the capacity of a beam or foundation to deform without losing its bearing capacity.

Question 26

Characteristics of aseismic buildings, benefits, and costs

Answer 26

Characterstics:
-Cross-bracing
-Using counterweights at the top of the building such as tanks of water that counter sway due to the lag in the movement of water prove to be less effective on their own compared to isolated bases.
-Adding rubber shocker absorbers – allow building to rock back & forth.
-Deep foundations
-Base isolation

Benefits:
-Protects people & property.
-Financially possible in HICs.
-Basic design can be replicated in LICs.

Issues:
-High costs for tall buildings.
-Older buildings and homes for people on low incomes are difficult to protect.

Question 27

Examples of tsunami defences, benefits, and issues

Answer 27

Examples:
-Hard engineering - Building sea walls & breakwaters. The latter slows down incoming waves.
-Homes may be raised or built with flooding in mind.
-Natural defences – planting & protecting mangrove forests.

Benefits:
-Reduces damage.
-Provides a sense of security.

Issues:
-Can be overtopped & thus lead to a false sense of security.
-Very high cost – Japan spent $11bn on building a 400km sea wall
-Unattractive – some of the Japanese are 15m high and residents can no longer see the sea & can no longer see oncoming tsunami waves.

Question 28

Diagram of strategies to monitor earthquakes

Answer 28

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Question 29

Diagram of strategies to monitor volcanoes

Answer 29

Question 30

Volcanoes- hi-tech monitoring: benefits, issues, example

Answer 30

Hi-tech monitoring:
-Used to monitor volcanoes.
-Tiltmeter, thermal imaging, seismometers, GPS meters.

Benefits:
-Warnings/evacuations can save lives.

Issues:
-Costly, mainly found in HICs/NEEs.
-Possibility of cry wolf syndrome
-Property is still damaged.

Example:
-GPS monitoring means that transmitters/receivers are placed around the volcano allowing scientists to monitor and record data about the volcano’s activity and changes thus allowing for a timely evacuation of the populations affected by potential
volcanic eruptions.

Question 31

Volcanoes- lava diversions: benefits, issues, example

Answer 31

Lava Diversions:
-Diverted barriers or diversion channels
Water cooling ( spraying – slows movement)
-Draining crater lakes reduces the formation of lahars.

Benefits:
-Directs lava away from people and buildings.
-Relatively low cost.

Issues:
-Only works for basaltic lava.
-Not feasible for the majority of explosive volcanoes.

Example:
-Lava diversions can be building walls or incorporating lava tubes as is used for volcanic eruptions on Mount Etna which have helped divert the lava from the more populous areas and so saving lives and property.

Question 32

Explain a way in which technology can be used to monitor volcanoes (Kilauea)

Answer 32

-The crater of a volcano can be monitored using GPS.

-The Hawaiian Volcano Observatory uses GPS to monitor Kilauea volcano on Big Island

-The movement of land is monitored, for example, whether the land is being inflated by magma underground, with an increase in the slope of a volcano

-Earthquakes are also monitored, which helps to check the stability of slopes

-Significant subsidence was detected in April 2018, and, after a period of 24 hour scrutiny, scientists advised Hawai’i County safety officials, and residents were prepared for the lava that destroyed 700 properties.

Question 33

What are the 3 main stages of response to a disaster?

Answer 33

1) Relief ( hours to days) immediate response, attempts to get people to safety.

2) Rehabilitation (days, weeks & sometimes months) attempts to get people back into their homes, so they are less vulnerable to secondary impacts e.g. disease & trauma.

3) Reconstruction ( weeks, months, years) long-term rebuilding of the economy and or society. Has the potential to return the quality of life to its original level or to improve it by decreasing the vulnerability of the community to a recurring event.

Question 34

Explain relief (first stage of response to a disaster)

Answer 34

-Effectiveness of this depends upon the capacity of the government, relationship with neighboring countries & the international community, as well as accessibility & degree of remoteness.

-Speed & effectiveness is critical at this stage.

-HICs tend to have agencies responsible for leading this e.g. Civil Defence in Italy, which also has a regional presence, with permanent professional leaders & 1,000s of trained volunteers, who can mobilize a response in hours. Make-shift hospitals & temporary shelters were set up after the L’Aquila earthquake. In LICS Red Cross & UNICEF..will provide support.

Question 35

Explain and give examples of search and rescue (relief)

Answer 35

-Trained search dogs can be sent into buildings deemed unfit for humans.

-Life detection units ( remotely managed devices) can be pushed into small spaces.

-NASA’s Finder – microwave radar to detect human heartbeats & breathing. Can detect through 9m of rubble ad 6m of solid concrete.

-Drones can fly over and survey & can be used long-term to map land use pressures.

-GPS – rescue teams can be tracked in large collapsed buildings.

-Online mapping e.g. Google Earth can help aid agencies mobilize logistical operations. Can be combined with open sourcing, where people on the ground can contribute & map issues – damage, injuries, and aid are needed. This leads can lead to a more effective response & avoids duplication.

Question 36

Explain how technology is used to locate survivors in a geophysical event

Answer 36

-After the 2015 Nepal earthquake, rescue teams used a FINDER unit to detect subtle movements that reveal the heartbeat of someone trapped in up to 9 meters of debris.

-Drones have been used for various disasters, and China used drones as early as 2008 for the Sichuan earthquake to quickly examine the damage to bridges, tunnels, and buildings.

Question 37

What factors hinder relief?

Answer 37

-Government capacity

-Relationships with neighboring countries and the international community

-Community resilience

-Timing of event

-Magnitude of event

-Spatial extent – remote/access

-Scale of loss

-Preparedness

-Secondary hazards

Question 38

Explain and give examples of rehabilitation

Answer 38

-HICs tend to move into this stage quicker.

-Following the L’Aquila earthquake in 2009 the rapid response enabled them to move into this phase within days and not weeks. Tent villages were established – family shelters, kitchens, dining tents, post offices, creche, clinic & temporary school.

Question 39

Explain and give examples of reconstruction

Answer 39

-L’Aquila – The government rapidly rebuilt apartment blocks on the outskirts of the town, as the town was deemed unsafe & a red zone.

-People were rehoused and given free rent for 12 months and free appliances and even clothing and bedding, but the speed of construction had left community groups out of the decision-making process and people were dissatisfied with the lack of community outdoor space, so integral to Italian culture.

-People complained about the lack of soul and services and that people no longer felt connected with each other. In the speed to rebuild, housing authorities had forgotten to integrate basic community participation.

-Locals stormed building sites, as they were frustrated their own town was not being rebuilt.

-In Japan, the locals were consulted more, with many towns voting against higher sea walls and opting to relocate to higher ground.

Question 40

Modified Park’s model showing different responses to hazard events

Answer 40

Question 41

Using an example, explain how management strategies have been implemented to attempt to promote continuing human development in a place that has experiences earthquakes (needed?)

Question 42

Haiti 2010 earthquake- pre- and post-event management strategies

Answer 42

Pre-disaster (preparedness and prevention:
-No building codes, most buildings were brittle
-Many work in the informal sector and have no insurance

Rescue and relief:
-Haiti had almost no central resources to support search and rescue and to administer an emergency response.
-Red Cross estimated 3mn needed emergency aid, but 7 days later only 200,000 had received food aid. Most of the aid arrived too late, but the international community did send sniffer dogs, tents & blankets.

Rehabilitation:
-6 months after the quake 98% of the rubble still remained.
-Hampered by Cholera outbreak.

Reconstruction:
-Government didn’t have enough money to rebuild.
-7yrs later 2.5mn still in need of aid.
-Today - Drones have been used in a project headed by Open Street Map Haiti to map the growth and risk factors associated with informal settlement growth following the earthquake.

Question 43

Christchurch 2011 earthquake- pre- and post-event management strategies

Answer 43

Pre-disaster (preparedness and prevention):
-Building standards were high, but some buildings hadn’t yet been repaired since the 2010 earthquake.
-Well educated – annual national earthquake drill – Get Ready website and Shake Out campaign.

Rescue and relief:
-Full emergency management plan was in place within 2 hours.
-Aid poured in – Australia gave $5mn

Rehabilitation:
-City was divided into 4 areas after the quake ( Green – undamaged could be built on, Orange – more checks needed, but can be built on, white – checks needed, red – unstable, difficult to build on).
-The government provided temporary housing and ensured damaged buildings are watertight.

Reconstruction:
-Many NGOs like Save the Children helped with long-term recovery and trauma.
-10,000 affordable homes built.

Question 44

Volcan de Fuego 2018 volcanic eruption- pre- and post-event management strategies

Answer 44

Pre-disaster (preparedness and prevention):
-Volcano was being monitored, but with only 1 seismometer.
-The government was told to evacuate – but didn’t act for 8 hours. They then sounded the alarm, but it was too late.

Rescue and relief:
-Only have unpaid volunteers.
-Aid agencies from around the world provided support – food kits, water& medical kits, and shelters.
-More evacuations due to lahars.

Rehabilitation:
-UNDP lead the recovery plan – started to construct more temporary shelters.

Reconstruction:
-Aid agencies now plan to equip six schools in the affected area with emergency preparedness kits so they can be better prepared for future disasters. They also plan to train teachers in emergency and risk management.

Question 45

Kilaeua 2018 volcanic eruption- pre- and post-event management strategies

Answer 45

Pre-disaster (preparedness and prevention):
-NASA satellites were used to see ground deformation and height of plumes
-People were well-educated and prepared.
-Siren & emergency alert ( audio message)

Rescue and relief:
-Hawaii county & civil defence agency are being overseen by FEMA & the Hawaii Emergency Management Agency.
-Public shelter set up.

Rehabilitation:
-Disaster recovery center set up, where people could seek grants, low-interest loans, and temporary housing.

Reconstruction:
-Governor requested assistance ( Federal aid) & this has been granted by Trump.
-Those who have lost houses were entitled to $34,000 in federal aid.

Question 46

Mocoa 2017 landslide- pre- and post-event management strategies

Answer 46

Pre-disaster (preparedness and prevention):
-Experts knew the town lied in a vulnerable position & questions have been raised as to why it wasn’t better prepared.
-Reports predicting this disaster had been written, but unfortunately ignored.
-Poor risk assessment and land use polices.

Rescue and relief:
-Central command in place 12 hours after the disaster - 1,300 people were brought in a day after the disaster by Police, Fire military, Civil Defence Red Cross to distribute food & water aid & search for survivors.

Rehabilitation:

-

Reconstruction:
-They have now carried out hazard mapping of landslide risk. The policy encourages relocation, but how do you relocate a population of 56,000 which is growing rapidly?
-2 yrs later struggling to get the funds & land to relocate 10s of 1,000s of residents.

Question 47

Port Hills 2011 rockfall- pre- and post-event management strategies

Answer 47

Pre-disaster (preparedness and prevention):
-Port Hill Christchurch - Should residents have been allowed to build on steep slopes in an earthquake-prone area? It had been identified for potential landslides & rockfalls in 1977 by the Environmental Agency & then by Engineering Lifelines in 1997.
-However, the last rockfall was 7,000 yrs ago and thus previous earthquakes haven’t triggered them. They weren’t prepared.

Rescue and relief:
-Shipping containers used to create a temporary barrier from further rock fall.
-Needed to persuade residents to leave.

Rehabilitation:
-Warning signs were put up in the area & red zones were identified.
-Residents in red zones could build rock fall protection structures – mesh fences..could apply for council funding.

Reconstruction:
-Residents banned from returning to homes for 5 years (180 homes), due to the risk of more rock falls.