Geophysical hazards Flashcards
What are geophysical hazards and what processes do they encompass?
Geophysical hazards refer to natural events resulting from the Earth’s internal processes. These include earthquakes, volcanic eruptions, and mass movements such as landslides, rockslides, debris flows, and mudflows. These hazards can have devastating impacts on human life, infrastructure, and the environment.
Describe the eruption of Mount Marapi on December 3, 2023. What were its effects?
On December 3, 2023, Mount Marapi erupted on the Indonesian island of Sumatra, producing an ash plume that reached heights of 3,000 meters. The eruption deposited significant amounts of volcanic ash in surrounding districts, leading to the tragic death of twenty-three hikers found near the volcano’s crater. This event highlights the dangers associated with volcanic activity in populated areas.
What are the three types of tectonic plate boundaries and their associated geological activities?
- Converging Boundaries: Tectonic plates move towards each other (→ ←), causing intense geological activity such as earthquakes and volcanic eruptions due to subduction or collision.
- Divergent Boundaries: Plates move apart (← →), leading to the formation of new crust through volcanic activity and frequent earthquakes as magma rises to fill the gap.
- Transform Boundaries: Plates slide past each other horizontally (↔), primarily resulting in earthquakes without significant volcanic activity.
What recent seismic activity has been observed in Iceland and its implications?
Since October 24, 2023, Iceland has experienced a series of earthquakes on the Reykjanes peninsula, indicating a high probability of an impending volcanic eruption. Evacuations have occurred in anticipation of potential hazards. The Fagradalsfjall volcano has erupted three times since 2021, creating new landscapes known as cooling craters.
Explain the structure of the Earth and its geological history.
The Earth’s structure consists of four main layers: the crust, mantle, outer core, and inner core. The crust, the outermost layer, is a solid rocky shell ranging from 5 to 70 kilometers in depth, with oceanic crust being thinner and denser than continental crust. Beneath the crust lies the mantle, a semi-solid layer approximately 2,900 kilometers thick, composed primarily of iron, magnesium, and silicon-rich rocks. The outer core is a liquid layer of iron and nickel, approximately 2,260 kilometers thick, which generates Earth’s magnetic field. At the center is the inner core, a solid sphere of iron and nickel with temperatures reaching 5,000-6,000°C. These layers are differentiated by their physical and chemical properties, with boundaries discovered through seismic observation
What types of volcanoes exist and what are their characteristics?
- Shield Volcanoes: Broad and gently sloping; formed by low-viscosity basaltic lava that flows easily over great distances (e.g., Mauna Loa in Hawaii).
- Composite Volcanoes (Stratovolcanoes): Steep-sided and characterized by alternating layers of lava flows and ash; often associated with explosive eruptions (e.g., Mount St. Helens).
- Cinder Cone Volcanoes: Smallest type; built from ejected lava fragments that solidify before falling to the ground; typically have steep slopes (e.g., Paricutin in Mexico).
What are primary and secondary hazards associated with volcanic eruptions?
Primary hazards include:
- Lava Flows: Molten rock that erupts from a volcano; can destroy everything in its path but moves slowly enough for evacuation in many cases.
- Ash Fall: Volcanic ash can travel hundreds of kilometers from the eruption site, causing respiratory issues for humans and animals, damaging crops, and collapsing roofs.
- Volcanic Gases: Emissions such as carbon dioxide and sulfur dioxide can be hazardous to health and contribute to climate change.
Secondary hazards include:
- Lahars: Mudflows formed when volcanic ash mixes with water from rainfall or melting snow; they can travel rapidly down river valleys.
- Rock Avalanches: Occur when volcanic structures collapse due to instability; can cause significant destruction.
Describe different types of magma and their implications for volcanic eruptions.
- Basaltic Magma: Forms at constructive boundaries; low viscosity allows for fluid lava flows; results in less explosive eruptions.
- Andesitic Magma: Intermediate silica content leads to moderate viscosity; can cause explosive eruptions.
- Rhyolitic Magma: High silica content results in high viscosity; often leads to highly explosive eruptions due to trapped gases.
Magma composition influences eruption style: basaltic eruptions tend to be less violent compared to rhyolitic eruptions.
What is liquefaction during an earthquake? Provide an example.
Liquefaction occurs when saturated soil loses its strength due to shaking during an earthquake, behaving like a liquid rather than solid ground. This phenomenon can lead to buildings sinking or tilting dangerously. A notable example is the Christchurch earthquake on February 22, 2011, where liquefaction caused extensive damage to infrastructure.
How do human activities contribute to geophysical hazards? List specific activities and their impacts.
Human activities such as mining disturb geological structures, while dam construction adds weight to faults that may trigger seismic events. Fracking increases seismicity by injecting high-pressure fluids into rock formations, altering stress levels in faults. Urbanization can also lead to increased runoff and erosion that destabilizes slopes.
What are the characteristics and impacts of lava flows as a primary volcanic hazard? Provide an example.
Lava flows are molten rock that erupts from a volcano and can travel several kilometers from the vent, depending on the viscosity of the magma. Basaltic lava flows are typically less viscous and can move at speeds up to 40 km/h. While they can destroy buildings and infrastructure, they usually move slowly enough to allow for evacuation. A significant example occurred during the 2014-2015 eruption of Kilauea in Hawaii, where lava flows threatened the town of Pahoa, causing evacuations and property damage
Describe pyroclastic flows and their associated risks. Include a historical example.
Pyroclastic flows are fast-moving currents of hot gas, ash, and volcanic rock that can reach speeds of up to 700 km/h and temperatures exceeding 600 °C. They are among the deadliest volcanic hazards due to their speed and density, capable of incinerating everything in their path. A historical example is the eruption of Mount Vesuvius in 79 AD, which buried the cities of Pompeii and Herculaneum under pyroclastic material, resulting in thousands of deaths.
What are the effects of ash fall as a primary volcanic hazard? Provide an example of its impact.
Ash fall consists of fine particles ejected during an eruption that can blanket large areas, leading to respiratory issues, damage to crops, and structural collapse due to weight accumulation on roofs. The 2010 eruption of Eyjafjallajökull in Iceland produced an ash cloud that disrupted air travel across Europe for several weeks, affecting millions and causing significant economic losses.
Explain volcanic gas emissions as a primary hazard and provide a notable incident.
Volcanic gases such as carbon dioxide, sulfur dioxide, and hydrogen sulfide can be released during eruptions, posing health risks to humans and animals. In extreme concentrations, these gases can lead to fatalities. A tragic incident occurred at Lake Nyos in Cameroon in 1986 when a sudden release of carbon dioxide from the lake suffocated approximately 1,700 people and thousands of livestock in nearby villages.
What are lahars, how do they form, and what is a significant example?
Lahars are volcanic mudflows created when volcanic ash mixes with water from rainfall or melting snow/ice. They can flow rapidly down river valleys, causing destruction far from the volcano. An example is the lahars generated by the eruption of Mount Pinatubo in the Philippines in 1991, which caused extensive damage to surrounding communities and infrastructure.
Describe jökulhlaups and their consequences with an example.
Jökulhlaups are glacial outburst floods that occur when volcanic eruptions beneath glaciers melt large volumes of ice rapidly. These floods can sweep away everything in their path. A notable instance was during the 2010 Eyjafjallajökull eruption in Iceland when melting ice caused jökulhlaups that destroyed roads and bridges.
What is acid rain resulting from volcanic eruptions? Provide an example of its effects.
Acid rain forms when sulfur dioxide emitted during an eruption reacts with water vapor in the atmosphere to create sulfuric acid. This can damage crops, forests, aquatic ecosystems, and infrastructure. An example is the acid rain resulting from the eruption of Mount St. Helens in Washington State in 1980, which adversely affected local agriculture and water quality.
How do landslides relate to volcanic activity? Provide a historical case study.
Landslides can occur due to volcanic activity when unstable slopes fail under the weight of accumulated ash or during explosive eruptions. They can also transform into lahars if water is involved. The Mount St. Helens eruption in May 1980 triggered massive landslides that devastated over 600 km² of forested land. These flashcards provide detailed information on various hazards associated with volcanic activity while including historical examples for better understanding and context.
What is the significance of the Earth’s crust and its relationship to human habitation?
The Earth’s crust is the outermost layer where humans live, and its thickness is comparable to that of a piece of paper relative to the entire planet. Beneath the crust lies the molten mantle, which cannot be accessed by humans due to extreme temperatures that would incinerate any material. The crust’s stability is crucial for human settlements, as geological processes beneath can lead to hazards like earthquakes and volcanic eruptions.
How does the movement of tectonic plates drive geological changes?
The movement of tectonic plates, driven by superheated magma from the mantle, causes shifts in land masses over geological time. Approximately 220 million years ago, these movements shaped the current configuration of continents. Evidence of this movement is seen in similar fossil records across different continents, indicating that they were once connected.
What types of seismic waves are generated during an earthquake? Describe their characteristics.x
- Primary Waves (P-waves): Fastest seismic waves, traveling through solids and fluids; characterized by alternating compressions and dilations.
- Secondary Waves (S-waves): Slower than P-waves, only travel through solids; involve transverse motion perpendicular to wave direction.
- Love Waves: Surface waves causing horizontal shaking; largest amplitude at the surface.
- Rayleigh Waves: Cause elliptical rolling motion similar to ocean waves; penetrate deeper but have lower speed than Love waves.
What factors increase a slope’s susceptibility to mass movement?
Several factors contribute to slope instability:
- Water: Increases weight and acts as a lubricant for materials.
- Erosion Processes: Coastal or river erosion can weaken slopes.
- Gradient of Slope: Steeper slopes are more prone to failure.
- Rock Type: Soft rocks like mudstone are more susceptible than hard rocks like limestone.
- Vegetation Removal: Lack of vegetation reduces soil stability as roots help anchor sediments.
How do human activities contribute to geophysical hazards? Provide specific examples.
Human activities such as mining can destabilize geological structures, while urbanization alters natural drainage patterns, increasing flood risks. For instance, dam construction adds significant weight to fault lines, potentially triggering earthquakes. Fracking has been linked to increased seismic activity due to high-pressure fluid injections into rock formations.
How does water influence slope stability and contribute to mass movement?
Water adds weight to the materials on a slope, increasing the overall load and reducing the frictional resistance that holds the slope together. When water saturates the soil, it can lead to a significant decrease in shear strength, making it easier for materials to slide downwards. Additionally, water can create hydrostatic pressure within soil layers, which destabilizes them further. For example, heavy rainfall can trigger landslides by saturating the ground, as seen during intense storms in regions like California.
What role does erosion play in increasing slope susceptibility to landslides?
Erosion processes, such as those caused by rivers or coastal waves, can undercut the base of a slope, making it steeper and less stable. Continuous erosion removes support from the bottom of slopes, leading to an increased likelihood of failure. For instance, coastal erosion along cliffs can lead to significant landslides during storms or high tides.
Explain how the steepness of a slope affects its susceptibility to mass movement.
The angle of a slope is critical; steeper slopes have a higher gravitational force acting on them, which increases the potential for mass movement. Any alteration that increases steepness—such as road construction or natural erosion—can lead to instability. For example, landslides are more common on slopes exceeding 30 degrees because gravity exerts a stronger pull on loose materials.
How does rock type and structure influence slope stability?
Different types of rocks have varying degrees of resistance to weathering and erosion. Soft rocks like mudstone are more susceptible to failure compared to hard rocks like granite. The arrangement of rock layers also matters; impermeable layers can trap water above them, leading to increased pore pressure and potential sliding. For instance, landslides often occur in areas with sedimentary rock formations that are easily eroded.
What impact does vegetation have on slope stability?
Vegetation plays a crucial role in stabilizing slopes by anchoring soil with root systems, reducing erosion, and absorbing excess water. The removal of vegetation—due to deforestation or wildfires—can significantly increase susceptibility to mass movement by destabilizing the soil structure. For example, areas affected by wildfires often experience increased landslide activity during subsequent rain events due to loss of root support.
How do human activities contribute to increased mass movement risks?
Human activities such as construction, mining, and land clearing can destabilize slopes by altering natural drainage patterns and increasing weight on vulnerable areas. For instance, grading roads on steep hillsides can create unstable conditions that lead to landslides during heavy rainfall or seismic activity. Urbanization often leads to increased runoff and reduced vegetation cover, further exacerbating the risk.
What is social vulnerability and what factors contribute to it?
Social vulnerability refers to the inability of individuals, organizations, and societies to withstand adverse impacts from hazards due to inherent characteristics of social interactions, institutions, and cultural values. It is linked to the well-being of individuals and communities and includes aspects such as literacy levels, education, peace and security, access to basic human rights, good governance, social equity, positive traditional values, customs, ideological beliefs, and collective organizational systems. For example, during flooding events, vulnerable groups such as children, the elderly, and people with disabilities may struggle to protect themselves or evacuate.
How does economic vulnerability affect disaster resilience? Provide an example.
Economic vulnerability is determined by the economic status of individuals and communities. Poorer populations are more susceptible to disasters because they often lack resources to build resilient structures or implement protective measures. For instance, families living in squatter settlements may be unable to afford housing in safer areas, making them more vulnerable to hazards.
What constitutes environmental vulnerability? Provide an example.
Environmental vulnerability involves natural resource depletion and degradation. Key aspects include the sensitivity of ecosystems to external pressures such as pollution and climate change. For example, wetlands like the Caroni Swamp are vulnerable to increasing salinity from seawater intrusion and pollution from stormwater runoff containing agricultural chemicals.
What is the Pressure Release Model in understanding vulnerability?
The Pressure Release Model identifies a progression of vulnerability based on root causes at the macro scale—such as economic development, infrastructure, and governance—coupled with dynamic pressures that impose limitations on society. For instance, rural poverty may drive migration to cities, overwhelming urban resources and leading to informal housing in hazardous locations. This can result in social unrest during crises due to a lack of community cohesion and effective governance.
What trends indicate increasing vulnerability to natural hazards in the future?
Despite improvements in disaster forecasting and building resilience, trends suggest that vulnerability may increase due to factors like an aging population and rapid urbanization near coastlines. For example, assessments indicate a 2 in 3 chance of a magnitude 6.7 or larger earthquake occurring in California’s San Francisco Bay area within the next 30 years.
How do geographical factors influence vulnerability to natural hazards?
Geographical factors play a crucial role in determining risk levels associated with natural hazards. Areas prone to multiple hazards—such as the Philippines with its typhoons, volcanoes, and earthquakes—experience heightened vulnerability due to their environmental conditions. Additionally, low-lying regions like Bangladesh are more susceptible to flooding due to high rainfall or snowmelt.
What defines a disaster according to geophysical hazards?
A disaster occurs when a hazard impacts a vulnerable population resulting in at least 10 fatalities and affecting over 100 individuals while prompting requests for international assistance.
List factors that affect geophysical hazard impacts.
Factors influencing geophysical hazard impacts include:
- Time of Day: The timing of an event can affect population exposure; for example, nighttime earthquakes may catch people unprepared.
- Degree of Isolation: Remote locations may face challenges in receiving timely aid.
- Slope: Steep slopes can exacerbate landslide risks.
- Location: Proximity to coastlines increases tsunami risk.
- Soil Type: Certain soil types are prone to liquefaction during earthquakes.
What factors contributed to the risk during the 2004 Indian Ocean tsunami?
Key factors included low altitude where most of the population lived at sea level, making them highly vulnerable when the tsunami struck. The direction of the wave also played a critical role in determining impact severity.
Describe physical factors influencing risk during the Nyiragongo eruption in 2021.
The slope gradient facilitated lava flow downhill through populated areas. The presence of valleys affected lava movement patterns, while locations of volcanic plumes influenced where lava would travel.
What physical factors contributed to risk during the Haiti earthquake in 2010?
The slope gradient influenced building stability; vegetation loss increased susceptibility; liquefaction was exacerbated by proximity to water bodies; and high groundwater levels further destabilized structures during shaking.
Explain how local geographical factors impact vulnerability during natural hazards.
Local geographical factors such as topography significantly influence risk levels from hazards. For instance:
- Steep unconsolidated soils are more prone to landslides.
- Low coastal plains are at risk from tsunamis.
- Sand-based sediments are susceptible to liquefaction.
What is the relationship between urbanization and vulnerability to natural hazards?
Urbanization can exacerbate vulnerability as rapid population growth in cities often leads to informal housing in hazardous areas. This migration can overwhelm city resources, resulting in inadequate infrastructure and services. For example, new arrivals in urban areas may lack social networks, leading to isolation and increased risk during crises.
How does the timing of a disaster impact its effects on a population? Provide an example.
The timing of a disaster can significantly influence its impact. For instance, the L’Aquila earthquake in Italy occurred at 3:32 AM when most residents were asleep, limiting their ability to respond quickly. If the earthquake had struck during the school day, it is believed that the casualties would have been much higher due to vulnerable school infrastructure.
What geographical factors influenced the response to the 2009 L’Aquila earthquake?
L’Aquila benefited from its proximity to Rome, allowing for a rapid mobilization of emergency services and resources. The quick response included establishing temporary shelters and initiating search and rescue operations within hours of the earthquake.
Describe the challenges faced by remote areas during natural disasters using Greenland as an example.
In June 2017, a landslide in Nugaatsiaq, Greenland, caused a tsunami that washed away houses and resulted in fatalities. The remote location posed significant challenges for response efforts due to sparse population, limited local resources, and difficult access for boats or vehicles. The municipality’s vast geographical area made timely aid delivery extremely challenging.
What were the impacts of the 2015 Nepal earthquake on infrastructure and humanitarian response?
The 7.9 magnitude earthquake in Nepal caused extensive destruction of infrastructure, with many areas becoming inaccessible by road. Humanitarian agencies faced logistical challenges in delivering aid due to damaged roads and landslides. Emergency response units were deployed via helicopter to remote locations like Rasuwa, where local hospitals were severely impacted.
How do local geological factors affect vulnerability during geophysical hazards?
Local geological factors such as soil type, slope gradient, and topography play critical roles in determining vulnerability. For example, steep unconsolidated soils are more likely to fail during heavy rainfall or seismic activity, while low-lying coastal areas are at higher risk from tsunamis due to their elevation relative to sea level.
What were the consequences of the Nyiragongo eruption for the city of Goma?
The Nyiragongo eruption resulted in significant destruction within Goma, with approximately 15% of the city’s buildings destroyed by lava flows. The airport was heavily impacted, losing two-thirds of its operational capacity. The chaotic evacuation led to approximately 120,000 people becoming homeless as they fled the advancing lava.
What secondary health hazards arose after the Nyiragongo eruption?
Following the Nyiragongo eruption, secondary health hazards included outbreaks of diseases such as malaria and cholera. However, due to a pre-existing presence of humanitarian agencies in the region due to ongoing conflict, these outbreaks were largely mitigated.
Discuss how the Eyjafjallajökull eruption affected global air travel and economy.
The Eyjafjallajökull eruption led to a massive ash cloud that disrupted air travel across Northern Europe for six days. This closure affected approximately 5 million travelers worldwide and resulted in an estimated loss of $200 million per day for the aviation industry. Additionally, sectors reliant on timely shipping—such as fresh produce and pharmaceuticals—faced significant supply chain disruptions.
What are the characteristics and hazards associated with the stratovolcano eruption in the Democratic Republic of Congo on July 4th?
The eruption occurred in a region characterized by fractures of tectonic plates and constant seismic activity related to the East African Rift between the Nubian and Somalian plates. The steep nature of the volcano led to rapid lava flows, exacerbating hazards. Vulnerabilities included low-income communities (LIC) with weak hazard protection and inadequate infrastructure.
What were the impacts of the stratovolcano eruption in the Democratic Republic of Congo?
The eruption resulted in 197 fatalities and left 24,000 children out of school. In response to the disaster, schools and communities established evacuation processes for emergencies. Employment rates surged from 80% to 95%, while acid rain caused by volcanic gases led to agricultural losses and contaminated drinking water. The World Health Organization (WHO) provided vaccines during a measles outbreak following the eruption.
Describe the Eyjafjallajökull eruption, including its geological context and primary hazards.
Eyjafjallajökull is a shield volcano located at a divergent plate boundary between the Eurasian and North American plates along the Mid-Atlantic Ridge. The primary hazard was an ash cloud generated by explosive interactions between hot magma and glacial water.
What secondary hazards arose from the Eyjafjallajökull eruption?
Secondary hazards included glacial outburst floods, lahars (volcanic mudflows), and rockslides resulting from melting ice interacting with volcanic activity
What vulnerabilities were present during the Eyjafjallajökull eruption?
High preparedness characterized this event, with numerous volcanic researchers monitoring activity. They detected small earthquakes leading up to the eruption. Temporary Internally Displaced Persons (IDP) shelters were established for 800 individuals, and families were well-prepared for evacuation.
What were the economic impacts of the Eyjafjallajökull eruption?
The aviation industry lost approximately $200 million per day due to flight cancellations caused by the ash cloud. The total cost to Iceland for managing the eruption’s impacts was estimated at $7.5 million. The Icelandic Red Cross registered all inhabitants in nearby areas within two hours, providing accommodation and support during a declared state of emergency.
What were the causes of the Guinsaugon landslide in the Philippines?
The Guinsaugon landslide was triggered by heavy rainfall from typhoons, deforestation practices such as slash-and-burn methods, and a small earthquake with a magnitude of 2.6. The mountainous terrain contributed to instability.
Discuss vulnerabilities associated with the Guinsaugon landslide.
Landslides frequently occur in this region; however, residents were unprepared for such an event. The landslide struck a rural area, complicating aid delivery efforts due to difficult access.
What were the impacts of the Guinsaugon landslide?
The landslide resulted in 1,126 deaths over a 4 km area, widespread vegetation destruction, soil erosion, and contamination of water supplies. International aid focused on repairing structures, building new houses for affected families, reforestation efforts, and establishing emergency care through field hospitals.
What factors contributed to the Mocca mudflow disaster?
The Mocca mudflow was caused by heavy rainfall (130 mm), flash flooding, landslides, overflowing rivers (Mocoa, Sangoyaco, Mulatto), steep relief, and ineffective land management policies. Mass deforestation exacerbated vulnerability by removing roots that stabilize land.
What vulnerabilities were present during the Mocca mudflow disaster?
Warnings had been issued for years about flooding risks due to proximity to rivers; however, relocation was difficult due to migrant workers and those fleeing guerrilla activities.
What were the impacts of the Mocca mudflow disaster?
The disaster resulted in an estimated 300-100 deaths, with around 400 injured and 200 missing. Neighborhoods along rivers were devastated, families were separated, and essential infrastructure such as roads and hospitals was damaged. The power supply was severely impacted (85% damaged), leading to declines in tourism and loss of industrial and agricultural activity.
What trends are observed in significant earthquakes from 1932 to 2017?
The trend shows an increase in the number of significant earthquakes over time. In 1932, fewer countries experienced significant earthquakes, while by 2017, countries such as India and Mozambique were affected. For example, Iran’s seismic activity level increased from level 1 in 1932 to level 5 in 2017.
What trends are observed in significant volcanic eruptions from 1818 to 2017?
The trend indicates an increase in significant volcanic eruptions over time. In 1818, significant eruptions were limited to Mexico at level 1. By 2017, eruptions occurred in multiple countries, including Italy, Indonesia, and Malaysia at level 4. Notably, no significant volcanic eruptions were reported in Mexico in 2017.
Why is there an apparent increase in earthquakes and volcanic eruptions?
The increase in reported earthquakes and volcanic eruptions is attributed not to a rise in actual occurrences but rather to improved monitoring and reporting technologies that enhance data collection and awareness of these events.
What does the graph showing natural disasters from 1970 to 2019 reveal?
The graph indicates an overall increase in natural disasters over time. While there is an increase in reported earthquakes and volcanic eruptions due to better reporting, landslide occurrences have risen significantly, likely linked to extreme weather events, population pressure, and land-use changes.
What does the graph depicting global annual deaths from natural disasters by decade illustrate?
The graph shows a rapid decrease in deaths from natural disasters since the early 1900s. Initially, droughts and floods caused the most fatalities from the 1920s to the 1960s; however, earthquakes have since become the leading cause of death despite not showing a consistent pattern of increase.
How has population growth influenced earthquake-related deaths?
The trend of increased deaths from earthquakes correlates with population growth. Between 1975 and 2015, the number of people living in seismic areas rose by 93%, increasing exposure to earthquake hazards as urban populations concentrated in vulnerable regions.
What are the implications of living near dangerous volcanoes?
In 2015, over 400 million people lived near one of the world’s most dangerous volcanoes. This proximity heightens their exposure to potential eruptions and associated hazards.
Describe the relationship between population density and earthquake risk.
Areas with high population density often coincide with tectonic plate boundaries where seismic activity is more frequent. Cities like Los Angeles and Mexico City are at significant risk due to their locations on active plates while also having large populations.
What does the cumulative death graph from earthquakes since 5000 BC indicate?
The graph shows a strong correlation between world population size and earthquake-related fatalities over time. As populations grow, particularly in urban areas, the potential for higher casualties during seismic events increases.
Discuss urbanization trends and their implications for disaster risk management.
Urbanization is projected to rise from 54% of the global population currently living in urban centers to approximately 68% by 2050. This trend raises concerns about megacities’ vulnerability; a high-magnitude earthquake could potentially result in catastrophic casualties if it strikes densely populated areas.
How do megacities relate to earthquake fatalities?
Regions with high populations tend to experience more earthquake-related fatalities. For instance, China has many supercities and has recorded around 290,000 deaths due to earthquakes.
What factors contribute to increased death risks during earthquakes?
Rapid urban growth leads to increased vulnerability as millions reside in inadequate housing made from poor materials situated in dangerous locations. By 2050, nearly half of the projected urban population may live under such conditions.
What anomalies are observed in the trends of natural disasters and droughts from 1970 to 2023?
An anomaly in the data shows that while the overall trend indicates an increase in natural disasters, the number of droughts significantly decreased in 2023 compared to previous years. This contrasts with the general upward trend observed from 1970 to 1980, followed by fluctuations until a notable decline in recent years.
How have deaths from natural disasters changed since the early 1900s?
The graph indicates a rapid decrease in deaths from natural disasters since the 1900s. In earlier decades, droughts and floods were the primary causes of mass fatalities. However, as time progressed, earthquakes emerged as the leading cause of death, despite not showing a consistent pattern of increase.
What significant changes occurred in the causes of death from natural disasters between the 1900s and recent decades?
In the early 1900s, droughts were the leading cause of death from natural disasters. By the mid-20th century, earthquakes became the primary hazard responsible for fatalities, while other hazards caused fewer deaths overall.
What is the projected population living in urban areas by 2050, and what implications does this have for disaster risk?
By 2050, it is projected that approximately 68% of the global population will reside in urban areas, equating to around 6.6 billion people. This urbanization trend raises concerns about increased vulnerability to natural disasters, particularly if high-magnitude earthquakes strike densely populated megacities.
What correlation exists between population density and earthquake fatalities?
The correlation between population density and earthquake fatalities is evident; regions with higher populations tend to experience more deaths during seismic events. This is particularly pronounced in countries with many supercities that are also prone to seismic activity.
What is Istanbul’s earthquake risk based on its geographical location?
Istanbul sits on the North Anatolian Fault, known for its rapid movement and regular sequence of earthquakes. Seismologists estimate a 35%-70% probability of a magnitude greater than 7 occurring near Istanbul within the next 30 years due to its geological setting.
What factors influence whether cities like Istanbul will experience a future megadisaster?
The likelihood of a megadisaster in cities like Istanbul depends on several factors, including the probability of high-magnitude earthquakes hitting the city, governance quality, and dynamic pressures faced by urban populations.
What role does government transparency play in mitigating disaster risks?
Government transparency is crucial for effective disaster risk management. It facilitates the implementation of urban planning laws, building regulations, and seismic design standards that can significantly reduce vulnerability to geophysical hazards.
How does education contribute to building resilience against geophysical hazards?
Education regarding disaster causes and preparedness enhances community resilience. Training drills and educational campaigns help individuals understand risks and appropriate responses during emergencies.
What are some strategies for building resilience against geophysical hazards?
Strategies include education on disaster causes, improved building design, tsunami sea walls, land-use zoning, preparedness measures like emergency plans, insurance options, and technology integration for tracking during emergencies.
What challenges do governments face when relocating populations at risk from geophysical hazards?
Relocating large populations poses significant challenges due to logistical issues, financial constraints, and social dynamics. For example, relocating over 56,000 residents in Mocoa presents difficulties compared to smaller communities like Guinsaugon with only 1,500 residents.
How did hazard mapping inform government policies in response to landslide risks?
Hazard mapping has been used to inform government policies by identifying high-risk areas for landslides. For instance, after mapping efforts revealed potential rock slide zones in Southern Leyte, communities were relocated away from dangerous areas to prevent future disasters
What trends are observed in the occurrence of significant earthquakes from 1932 to 2017?
The trend indicates an increase in significant earthquakes over time, with more countries experiencing seismic activity in 2017 compared to 1932. For example, Iran’s seismic activity level increased from level 1 in 1932 to level 5 in 2017, highlighting a broader geographical spread of significant earthquakes.
What trends are observed in significant volcanic eruptions from 1818 to 2017?
The trend shows an increase in significant volcanic eruptions over time. In 1818, significant eruptions were limited to Mexico, while by 2017, eruptions occurred in multiple countries, including Italy and Indonesia at level 4. Notably, the data shows no significant volcanic eruptions in Mexico by 2017.
What factors contribute to the perception of increasing earthquakes and volcanic activity?
The perceived increase in earthquakes and volcanic activity is largely due to advancements in monitoring technology and improved reporting practices rather than an actual rise in occurrences.
What does the graph showing natural disasters from 1970 to 2019 reveal about landslides?
The graph indicates a clear increase in landslide occurrences, which may be attributed to a rise in extreme weather events, population pressure, and changes in land use practices.
What anomalies are present in the trends of natural disasters and droughts from 1970 to 2023?
Anomalies include a significant decrease in the number of droughts reported in 2023 compared to previous years, despite an overall trend of increasing natural disasters.
How have deaths from natural disasters changed since the early 1900s?
Since the early 1900s, deaths from natural disasters have decreased significantly. Initially, droughts and floods were the leading causes of fatalities; however, since then, earthquakes have become the primary cause of death from natural hazards.
What is the correlation between population growth and earthquake-related fatalities?
There is a strong correlation between population growth and earthquake-related fatalities. The number of people living in seismic areas increased by 93% from 1975 (1.4 billion) to 2015 (2.7 billion), leading to greater exposure during seismic events.
What is the risk associated with living near dangerous volcanoes?
In 2015, over 400 million people lived near one of the most dangerous volcanoes globally, increasing their exposure to potential eruptions and associated hazards.
What trends are observed regarding urbanization and its impact on disaster risk?
Urbanization trends indicate that by 2050, approximately 68% of the global population will live in urban areas. This shift raises concerns about increased vulnerability to natural disasters, particularly if high-magnitude earthquakes strike densely populated megacities.
What relationship exists between earthquake fatalities and population density?
Regions with higher population densities tend to experience more deaths during earthquakes. This trend is particularly evident in countries with many supercities prone to seismic activity.
How does Istanbul’s geographical location influence its earthquake risk?
Istanbul is situated on the North Anatolian Fault, which is known for its rapid movement and regular sequence of earthquakes. Seismologists estimate a probability of between 35%-70% for a magnitude greater than 7 occurring near Istanbul within the next three decades.
What factors influence whether cities like Istanbul will experience a future megadisaster?
The likelihood of a megadisaster depends on several factors including the probability of high-magnitude earthquakes hitting urban areas, governance quality, dynamic pressures faced by populations, and effective implementation of urban planning laws.
What role does government transparency play in disaster risk management?
Government transparency is essential for effective disaster risk management as it enables the implementation of urban planning laws, building regulations, and seismic design standards that can mitigate vulnerabilities to geophysical hazards.
How does education contribute to resilience against geophysical hazards?
Education about disaster causes and preparedness enhances community resilience by informing individuals about risks and appropriate responses during emergencies through training drills and educational campaigns.
What strategies can be employed for building resilience against geophysical hazards?
Strategies include educating communities about disaster causes, improving building designs for resilience, constructing tsunami sea walls, implementing land-use zoning practices, preparing emergency plans, obtaining insurance coverage for properties at risk, and utilizing technology for tracking during emergencies.
What challenges do governments face when relocating populations at risk from geophysical hazards?
Relocating large populations poses logistical challenges due to financial constraints and social dynamics. For example, relocating over 56,000 residents in Mocoa presents difficulties compared to smaller communities like Guinsaugon with only around 1,500 residents.
List the names of all the plates in the world.
- North American Plate
- Juan de Fuca Plate
- Pacific Plate
- Cocos Plate
- Nazca Plate
- South American Plate
- African Plate
- Antarctic Plate
- Eurasian Plate
- Indo-Australian Plate
- Philippine Plate
- Pacific Plate
- Caroline Plate
- Fuji Plate
Where is a convergent boundary located?
Where is a divergent boundary located?
Where is a transform fault located?
Where are the worlds earthquakes and volcanic activity primarily located?
Along oceanic trenches and submarine mountain ranges.
What is the concept of isostacy?
Denser material will need deeper roots to be elevated. Less dense material will be more elevated. The concept of isostacy is like buoyancy, and explain the vertical distribution of the earth’s crust based on thickness and density like a piece of wood. Isostacy is one reason we have earthquakes on continental plates, sometimes caused by humans.
List hotspot for volcanoes.
- Galapagos
- Yellowstone
- Iceland
- Azores
- Afar
What was the elevation of Mount St. Helens before and after the eruption?
Before in 1980 it was 2,950m and after in 1980 it was 2,550m.
Describe each part of the earthquake.
- Epicenter
- Wave fronts
- Focus
- Fault
- Fault scarp
List different types of mass movement.
- Rock avalanche
- Rockslide
- Earthflow
- Rock creep
- Mudflow
- Topple
What are the factors increasing shear stress?
- Removal of lateral support through undercutting or slope steepening. For example by rivers, wave action and previous rock falls/slides.
- Removal of underlying support, by undercutting rivers and waves, road construction.
- Loading of slope, through increased weight of water, debris or construction, water injection through mining.
- Lateral pressure, water and ice in cracks, swelling and pressure release.
- Transient stresses, earthquakes, wind moving trees, mining.
What are the factors reducing shear strength?
- Weathering effects, disintegration of granular rock, chemical weathering processes.
- Changes in pore water, saturation, softening of material pressure.
- Changes in structure, creation of fissures in clays, remoulding of sands and clays.
- Organic effects, biological weathering, decay of roots and burrowing animals.
What are the slow mass movements?
- Soil creep
- Soilfulction
What are the fast mass movements?
- Rockslide
- Landslide
- Earthflow
- Mudflow
- River
What are the dry mass movements?
- Soil creep
- Rockslide
- Soilfluction
- Landslide
What are the wet mass movements?
- River
- Mudflow
- Earthflow
Where do landslides occur and where are the greatest risk?
Landslides can occur anywhere in the world but there is a higher risk in steep mountainous regions with coarse soil. Landslide risk is greatest in populated regions with high rainfall events, such as tropical storms and lead to slope saturation and river flooding. In addition regions experiencing population pressure, deforestation, road construction, mining and plantation all lead to greater risk of landslides.
What is the trend with high magnitude earthquakes?
High magnitude earthquakes tend to be associated more with deeper earthquakes, related to subduction zones. The Pacific Ring of Fire is not only associated with its explosive volcanic activity but also with high magnitude earthquakes. These earthquakes tend to be lower in frequency. However, some geologists argue that the highest magnitude earthquakes tend to come in twos. Although there is limited statistical evidence to support this, what is clear is that large earthquakes often cluster with many aftershocks, some of which can be almost as severe as the first.
What are the different levels of VEI?
0 - trickle of lava - Hawaiian volcanoes of Kilauea - not tallest part of island but erupts more actively - shield volcanoes
1 - Gentle eruption - Italy Stromboli - Strombolian volcanoes
2 - several mild explosions - catastrophic - lassen peak Northern California
4 - happens every other year - 2020 Iceland of Eyjafiajallajokull - go high into the air
5 - things more dramatic - Mt Vesuvius + Mt St. Helens - blue top + lost altitude + erupt out of side - Volcanic
6 - colossal eruptions - Krakatoa - triggered tsnunami - 1883
7 - every 1000 years - Indonesia Mt Tambora
8 every 50,000 - Yellowstone caldera would reach this level if it were to erupt again - us - national park - so massive that people don’t understand it is a volcano - supervolcano - if it erupted it would make big difference - mant deaths, people, animals - climate would change, for example Plinian.
What are the four biggest volcanic eruptions in history?
- Wah Wah Springs
- 30 million years ago
- >550 cu km (VEI 8) - Toba
- 74,000 years ago
- 2800 cu km (VEI 8) - Yellowstone
- 640,000 years ago
- 1000 cu km (VEI 8) - Long Valley California
- 760,000 years ago
- 580 cu km (VEI 7)
How are volcanic eruptions and their strength measured?
Volcanic Explosivity Index (VEI).
List the factors that made people high risk in the 2010 earthquake in Port-au-Prine in Haiti.
- Unsafe conditions: High unemployment and dependency on informal economy leads to high poverty rates and low resilience to shocks.
- Root cause: Poor quality housing, materials and corrupt building regulation led to catastrophic damage.
- Root cause: Poor governance and legal systems to regulate and enforce building codes and land use zoning.
- Unsafe conditions: Social and economic desperation can lead to rapid social decline, protest, riots, crime and looting.
- Root cause: High density housing with limited acess to electricity, sanitation and rood connection hindering emergency services.
- Dynamic change: Steep slopes are stripped of forest vegetation due to urban sprawl.
- Dynamic change: Rapid rural to urban migration and growth of informal settlements places local authorities under pressure.
What is the disaster risk equation?
Risk = (hazards x vulnerability)/capacity
What is the progression of vulnerability?
- Root causes:
- Limited access to: power, structures, and resources
- Ideologies: political systems and economic systems - Dynamic pressures:
- Lack of: training, local investment, and press freedom
- Macro-forces: rapid population, rapid urbanisation and deforestation - Unsafe conditions: Physical environment, local economy, social relations and public actions
- Disaster
Or natural hazards can occur leading straight to a disaster.
What factors make a vulnerable system?
Exposure, sensitivity, and resilience of:
- population
- economy
- land use and development
- infrastructure and facilities
- cultural assets
- ecosystem goods and services
Ability, resources and willingness to:
- prepare
- mitigate
- response recover
What factors have the potential for catastrophic and chronic physical events?
- past recurrence intervals
- future probability
- speed of onset
- magnitude
- duration
- spatial extent
What two factors make up the risk of disaster?
The natural hazard itself, and factors such as the duration of it as well as the vulnerability of the system.
What is the trend of the number of people reported killed by natural disasters from 1990-2011?
The number has gone down, in 1900 it was about 1.25 million, and in 2010 it decreased to about 0.25 million.
Describe a map showing the world risk index of vulnerability to natural disasters.
- Very high includes Chile and Madagascar
- High includes Angola and Algeria
- Medium includes China and Mexico
- Low includes Australia and the USA
- Very low includes Spain and Canada
What warning system does the Solomon Islands and Cook Islands use?
Solomon Islands use truck horns as a siren, solar-powered three colour emergency light system to monitor floods. Cook Islands have their children in Tautu, Aitutakie practice tsunami evacuation plan.
What are the social, economic and environmental long-term and short-term social effects earthquakes and volcanoes have?
Social (short-term):
- death/injuries
- seperation
- homeless
Social (long-term):
- death/injuries
- homeless
- disease outbreak
Economic (short-term):
- loss of jobs
Economic (long-term):
- loss of jobs
- costs of repair (eg. housing)
Environmental (short-term):
- soil degradation
- change in river/coastline
- damage to wildlife
Environmental (long-term):
- soil degradation
- rivers/coastlines change
- damage to wildlife
- weather/climate
Explain the earthquake in Haiti in 2010.
The Haiti quake was a magnitude 7.0 and is thought to have occurred on a set of blind thrusts associated with a major strike-slip fault. Haiti was poorly prepared for the earthquake. Their last comparable earthquake occurred more than 200 years ago and strategic thinking and public perception of risk was not apparent. In addition, the country is one of the poorest in the world. Before the earthquake struck 54% of the population lived in abject poverty. 20% of the country’s GDP comes from remittances. It is reasonable for the government to place earthquake preparedness low in its overall priorities, given the multitude of daily challenges that the nation faces.
More than 250,000 people were killed. Another 300,000 were injured. Due to widespread building collapse. More than 600,000 people left Port-au-Prince to stay with families outside the capital. The quake displaced 1.5 million people.
By 2017, 55,000 people still lived in temporary camps. The UN reported that 2.5 million Haitians needed humanitarian aid at a cost of $270 million. The country was also hit by an outbreak of cholera introduced by UN aid workers. The country would go on to battle cholera up to 2019.
The damage costs are uncertain, ranging from $8.5 billion to over $14 billion, double that of Haiti’s GDP. To give that some context the massive earthquake and tsunami that hoi Japan in 2011 had an economic impact of 4% of Japan’s GDP. The Haiti quake damaged the main airport, most of the ports and almost all the paved roads. It damaged nearly 300,000 homes, destroying over 100,000 of them. 30,000 commercial buildings were destroyed. 6 months after the quake, 98% of the rubble remained uncleared, some still blocking vital access roads. The clothing industry, which accounted at the time for two-thirds of Haiti’s exports, reported structural damage at manufacturing facilities. It is estimated that 1 in 5 jobs were lost as a result. The quake hit Port-au-Prince, Haiti’s capital. This crippled government efforts to restore order. It killed 25% of the civil servants living in the capital. The quake damaged or destroyed 60% of the city’s government buildings and 80% of the city’s schools.
Haiti essentially had no buffer capacity to cope with the shock of the earthquake and in the following two years, according to the UN, only 43% of the $4.59 billion promised in aid had been received and disbursed.
What were the vulnerability factors for the 2010 Haiti earthquake?
Physical Risks:
- Sits on an active fault line - infrequent earthquakes
- Susceptible to secondary health hazards
- Also vulnerable to hurricanes
Root Causes:
- Very underdeveloped country - with very vulnerable communities
- Poor governance
- High levels of corruption
- High dependency on international donors
- International donor distrust in government
Dynamic Pressures:
- Rapid Urbanisation
- Growth of slums on steep slopes
- Deforestation on slopes
- Poor urban planning - lack of safe sanitation
- Poor building regulations/ enforcement
Unsafe Conditions:
- Low community cohesion
- Lack of disaster response training, capacity
Explain the earthquake and tsunami in Sulawesi in 2018.
The 7.5 magnitude earthquake occurred at 6 pm during rush hour but had been proceeded by a number of pre-shocks. It is thought that 150km of the Palu-Koro fault ruptured. Intensive shaking was experienced at Palu and Donggala. The earthquake created a tsunami wave that ranged in height along the coast from 4 meters to 7 meters in Donggala. The tsunami size had surprised geologists and is thought to have been increased by submarine landslides and liquefaction. In addition to the tsunami, widespread liquefaction was reported in two locations. The most affected areas are the Petobo sub-district in southern Palu and the village of Balaroa, just outside the city, both locations some distance from the coast. In total 4,340 people were killed with a further 667 people missing.
Even though officials did send warnings via telephone and television, tsunami alarms were not activated. They had apparently been damaged in the earthquake There was a festival taking place on Talise Beach in Palu and this continued with most of the attendees not realising that there was a possibility of a tsunami. Eyewitnesses even stated that some people were still strolling on the beach when the tsunami struck. It was estimated that hundreds were caught off guard and swept away by the waves.
70,000 homes were destroyed in the earthquake as well as a major section of the Atapura Hospital, a large 8 storey hotel collapsed, the mosque and the Tatura mall trapping many people inside. More than 3,000 schools, affecting more than 20,000 students were damaged. The government announced it would take over a year to repair the schools.
Liquefaction was just as dramatic as the tsunami. The Indonesian National Board for Disaster Management announced that 2,050 houses were destroyed by the mudflow in Petobo and an area of 180 hectares was shifted by the liquefaction. Balaroa almost disappeared as the ground collapsed, with most of the village’s 1,747 houses sinking into the mud. Of the 2,000 inhabitants, 600 are known to have died, with many hundreds of others missing. The liquefaction reportedly shifted an area of 47,8 hectares. The total cost of the earthquake as reported by the Disaster Response was $911 million.
Many people lost everything and the city of Palu has experienced business closure and outmigration. The government has declared five areas including three neighbourhoods hit by liquefaction in Palu red zones, vulnerable to extreme risk of hazards and uninhabitable. People have been offered no compensation but rather land swaps encouraging them to move away.
Two years after the disaster thousands of people were still living in tents. The recovery costs to the region are estimated to be $2.5 billion. There have been massive long-term economic impacts. The major roads connecting Palu to neighbouring cities remain damaged. Only one container crane is operating at the Pantoloan seaport, which slows the loading and unloading process. The airport suffered massive cracks and in 2019 was only partly in service, hampering food and aid distribution. In addition, the Gumbasa irrigation damaged in the earthquake remains out of use and this is responsible for 8,000ha of farmland.
What were the vulnerability risks for the Sulawesi earthquake and tsunami in 2018?
Physical Risks:
- Highly exposed to high magnitude earthquakes, tsunamis
- The coastal orientation of Palu and Donggala increased wave height
- Soil sediments are known to be at risk of liquefaction
Root Causes:
- Archipelago nation means central governance is challenging and accessibility low
- Emerging economy - high levels of income inequality
- A relatively poor rural fishing community
Dynamic Preassure:
- Population growth
Unsafe Conditions:
- The government had ignored scientific warnings of liquefaction risk
- Lack of accurate warnings, the size of the tsunami poorly predicted
Summarise the facts of the Sulawesi earthquake and tsunami.
- Magnitude: 7.5
- Speed of onset: No warning
- Duration: 30 seconds
- Depth: 10km
- Area affected: 150km^2
- Frequency: Very frequent, 15 earthquakes greater than 6.5 near Palu in the last 100 years
- Predicability: 1 minute
- Secondary hazards: Aftershocks (5.5), Tsunamis up to 6 metres in places, landslides and liquefaction and volcanic eruption
- Epicenter: 27km northeast from Donggala
- Deaths: 4,340
Summarise the facts of the Haiti earthquake in 2010.
- Timing: 16.54
- Magnitude: 7.0
- Speed of onset: No warning, eyewitnesses say ‘suddenly’
- Duration: 35-60 seconds
- Depth: 13 km
- Area affected: 120km^2
- Frequency: Last earthquake 150 years ago
- Predictability: None
- Secondary hazards: Over 45 aftershocks > 4.5 and two aftershocks of 5.9 and 5.5 within a few days and 5.9 on the 20th of January. One town experienced a localised tsunami
- Epicenter: 25km southwest of Port au Prince
- Deaths: estimates suggest 250,000
Compare the impacts of the Haiti and Sulawesi earthquakes
Haiti:
- Timing: January 12th, 2010, 16:53
- Deaths: around 220,000
- Cost: around $14 billion
- Homes lost: 106,000
- Homes damaged: 294,283
- Temporary displacement: 1.5 million
- Health: Cholera outbreak causing 9470 deaths as of March 2017
Sulawesi:
- Timing: September 28th, 2018, 18:02
- Deaths: 4,340
- Missing: 667
- Cost: emergency response $50 million
- Recovery costs: around $911 million
- Homes lost or damaged: 70,000
- Temporary displacement: 480,000
- Health: Fear of diarrhoea and dysentery and cholera outbreak
Explain the Nyiragongo eruption
The volcano was well-researched and although the scientific equipment being used at the time was outdated it was providing regular data to suggest an imminent eruption. The problems with the early responses were based on poor communication.
There was no real means to communicate the situation to the public and so in the absence of any clear warning, a chaotic public evacuation occurred at the same time as fast-moving lava was entering the town.
A 13km fissure opened in the south flank of the volcano, spreading in a few hours from 2,800m to 1,550m elevation and reaching the outskirts of the city of Goma, the provincial capital on the northern shore of Lake Kivu. Lava streamed from three spatter cones at the end of the fissure and flowed in a stream 200 to 1,000m wide and up to 2m deep through Goma. At least 15% of Goma, comprising 4,500 buildings was destroyed, leaving about 120,000 people homeless.
The lava flow hit the commercial centre and covered the northern end of the airport and runway at Goma International Airport, leaving two-thirds of it destroyed and out of use. Given Goma’s geographical isolation in DRC, this vital transport hub was a massive loss.
Belated evacuation warnings were given and 400,000 people were evacuated from the city. 100,000 people moved west and a further 300,000 crossed over into Rwanda. Immediately after the eruption stopped, a large number of earthquakes were felt around Goma and Gisenyi. This swarm activity continued for about three months and caused the collapse of more buildings.
Most estimates suggest that about 147 people died in the eruption from asphyxiation by carbon dioxide and buildings collapsing due to the lava and earthquakes. 50 people died in one single explosion at a petrol station. This is clear evidence of poor public awareness and low perception of risk. People were queueing to fill their cars with petrol at the time. Due to long-term political unrest and conflict impacting 6 countries in the region, displaced people were quick to return. This may have been because of the widespread looting that had been reported in the first few days. Within days most people had returned and were either living in camps close to Goma or with host families in the city. Several thousand people remained at the Esco camp, a transit camp sponsored by the Goma-based Congolese Assembly for
Democracy (RCD-G) located 8 km west of Goma. Some people were severely injured because they were walking on the crust of the lava. Communities showed incredible resilience setting up market stalls and rebuilding within days.
In total 12,500 families lost their homes leaving 120,000 people homeless. International non-governmental organisations (NGOs) estimated an increase in unemployment levels from 80 to 95%. 45 of 150 schools in Goma were destroyed leaving 24,000 children out of school. 5 of 20 health clinics and one important hospital were lost.
In total UN aid amounted to just over $33 million. With a large presence of humanitarian agencies already in the region due to conflict many secondary factors such as malaria and cholera outbreaks were avoided. Financial agricultural support was given to both the worst hit families as well as the host families
What were the vulnerability factors for the Nyiragongo Eruption in 2002?
Physical Factors:
- Highly exposed to risk from fast-flowing lava from multiple fissure eruptions in close proximity to the city
Dynamic Pressures:
- Population growth in the city
- Very low educational base - poor perception of risk
Root Causes:
- Very underdeveloped country and an even poorer region
- Distance from the capital city and central government leads to underinvestment
- Remoteness and poor accessibility
- High dependence on international aid and NGOs
Unsafe Conditions:
- Poor communication and disaster response measures
- High levels of political instability and militia groups
Summarise the Nyriagongo eruption in 2002.
- Timing: 09:30
- Magnitude: VEI 1
- Speed of onset: Increased seismic activity and fumaroles prior to eruption. 13km fissure opened up in a matter of hours, and fast flowing lava up to 40km/h. Lava lake drains out from crater along fissures.
- Duration: 48 hours
- Area affected: 3 separated fissures with 13% of the city covered in lava
- Frequency: Last eruption 1977
- Predictability: High-value forecast, but exact timing impossible. The volcano was well monitored.
- Secondary hazards: open fissures, petrol station explosion, unsafe lava flow when walking over it.
- Proximity to hazard: City of Goma, 18km south of the volcano
- Deaths: around 147
Explain the Eyjafjallajökull Eruption in 2010.
Eyjafjallajokull is a shield volcano that lies under a glacier. The eruption was well monitored and forecast, with increased seismic activity and displacement taking place prior to the eruption phase. Iceland has a huge amount of experience in managing tectonic hazards and so the operation of evacuation was relatively smooth and the families involved were cooperative and well-prepared. The nature of the eruption was also well understood and so the South Road was closed and temporary bridges were removed.
The initial eruption was effusive with lava visibly shooting out from the crater, the second phase was phreatic (caused by magma mixing with ice) and caused a 9,000-meter high tephra cloud to form. Over 4 weeks it is believed that 250 cubic tonnes of ash was ejected from the volcano.
In the immediate phase of the eruption, 800 local people were evacuated from nearby homes and farms, with only short temporary visits permitted to tend to livestock. The coastal plain and ring road was subjected to localised flooding from the Jökulhlaup, (glacial flood). In total, the economic cost to Iceland in managing these impacts amounted to $7.5 million.
Due to the eruption coinciding with an infrequent prevailing wind and positioning of the Polar Jet Stream, the ash cloud was dispersed across Northern Europe causing widespread disruption to the aviation industry. Flights in Northern Europe were grounded for the first 6 days of the eruption. It’s estimated that the closure of European airspace left 5 million travellers stranded abroad with several thousand people affected as far as Asia and the US.
The International Air Transport Association (IATA) estimated that the aviation industry lost $200 million a day. Other impacts included supply-side problems with small electronic hardware products and fresh fruit and flowers. On each of the 6 days, Kenya was forced to destroy 400 million tonnes of flowers costing its sector $millions. Other sectors included the supply of pharmaceuticals and the export of electronic hardware out of Europe. Schools were particularly impacted with many students and teachers stranded abroad due to its timing in the Easter holiday. In addition, some major sporting events and several high-profile global conferences were cancelled. In total, the estimated global cost of the eruption is thought to have been $5 billion.
How does education about causes and improved transparency build resilience?
Education about the causes of natural hazards and improved transparency in government practices are essential for building resilience. This knowledge helps communities understand risks and prepare adequately for potential disasters, fostering a culture of safety and proactive measures.
What role does building design play in disaster resilience?
Incorporating hazard-resistant designs in building construction is crucial for minimizing damage during natural disasters. This includes using materials and architectural techniques that enhance structural integrity against earthquakes, floods, and other hazards.
How do tsunami sea walls protect coastal communities?
Constructing tsunami sea walls provides a physical barrier to protect coastal communities from tsunami waves. These structures are designed to absorb and deflect wave energy, reducing the impact on populated areas during tsunami events.
What is the importance of projection/prediction in disaster preparedness?
Utilizing advanced projection and prediction technologies enhances preparedness for natural disasters. Accurate forecasting allows communities to implement timely evacuations and safety measures, potentially saving lives during imminent threats.
How does slope stabilization prevent landslides?
Slope stabilization techniques aim to prevent landslides and erosion in vulnerable areas. Methods include installing retaining walls, drainage systems, and vegetation to enhance soil stability and reduce the risk of mass movements.
Why is land use zoning important for disaster risk management?
Implementing land use zoning regulations helps manage development in high-risk areas. By controlling where buildings can be constructed, authorities can minimize exposure to hazards such as floods, landslides, and earthquakes.
What should be included in preparedness plans for natural disasters?
Preparedness involves creating comprehensive emergency plans that outline actions individuals and communities should take before, during, and after a disaster. This includes practicing evacuation procedures and ensuring access to emergency supplies.
How do emergency plans improve disaster readiness?
Emergency plans should include regular drills to familiarize communities with response protocols during disasters. For example, earthquake drills help residents practice safe behaviors during seismic events, improving overall readiness.
How does insurance enhance financial resilience against natural hazards?
Obtaining insurance coverage for properties at risk from natural hazards increases financial resilience. Insurance can help individuals and communities recover more quickly after a disaster by providing funds for repairs and rebuilding efforts.
What technological advancements aid in emergency response during disasters?
Advancements in technology allow emergency services to track individuals during disasters. For example, applications like “Find My Phone” can assist rescuers in locating people who may need help during emergencies.
What are lahar diversions and how do they mitigate volcanic risks?
Lahar diversions are engineered channels designed to redirect volcanic mudflows away from populated areas. These structures help mitigate the impact of lahars by controlling their flow path during eruptions.
How does hazard mapping inform government relocation policies?
Hazard risk maps identify areas vulnerable to landslides or other hazards. For instance, a hazard risk map for Southern Leyte in the Philippines helped inform government planning for the relocation of Guinsaugon and six other villages deemed too dangerous for habitation.
How does hazard mapping inform urban zoning decisions?
Hazard maps based on the Modified Mercalli Scale assist in urban planning by revealing spatial differences in impact across regions. These maps guide authorities in making informed decisions about where to locate infrastructure and residential areas based on seismic risk.
What does liquefaction potential mapping reveal about Christchurch’s vulnerability?
The liquefaction potential map for Christchurch produced in 1995 highlighted areas at risk from liquefaction during earthquakes. This information could have prevented significant economic costs had it been utilized effectively in urban planning prior to the 2010 earthquake.
What is the role of stricter building codes in disaster resilience?
Stricter building codes are essential for ensuring that new constructions meet safety standards against natural hazards. Istanbul’s Urban Transformation Law mandates that buildings not meeting earthquake hazard standards be demolished, impacting millions of structures over the next two decades.
Explain the landslide in Guinsaugon in 2006.
On February 17, 2006, the village of Guinsaugon in Southern Leyte, Philippines, was devastated by a catastrophic landslide triggered by two weeks of heavy rainfall. The landslide occurred around 10:30 AM local time and buried the village, which had an estimated population of 1,400 people.
The official death toll reached 1,126, with many more initially reported missing. Estimates suggested that up to 2,000 people could have been buried under the debris, including 250 children from a local school.
About 30 individuals were reported injured during the disaster.The landslide destroyed approximately 281 houses and an elementary school, which was filled with students at the time. The event displaced around 19,000 residents, leading to significant humanitarian challenges.
The landslide had several secondary effects:
- Infrastructure Damage: Roads were blocked, complicating rescue efforts and access to the area. A “no-fly zone” was declared to prevent additional landslides triggered by helicopter downwash10.
- Flooding Risk: The landslide blocked tributaries of nearby rivers, raising concerns about potential flooding in surrounding areas due to obstructed water flow.
- Psychosocial Impact: The loss of life and destruction of a community led to profound psychological effects on survivors and families of victims.
The landslide was primarily caused by:
- Heavy Rainfall: Over 1,200 millimeters of rain fell in just ten days leading up to the disaster, saturating the soil and destabilizing the slopes.
- Geological Factors: The village was located near the Philippine Fault, where tectonic activity had weakened the rock formations. The presence of rice paddies also contributed to the landslide’s severity by acting as a lubricant for the moving debris.
Explain the landslide in Mocoa in 2017.
In April 1, 2017, a devastating landslide struck Mocoa, a municipality in southern Colombia. Triggered by heavy rainfall and subsequent flooding, this disaster occurred during the early morning hours when many residents were asleep.
The landslide resulted in at least 300 fatalities, with many bodies never recovered due to the extent of the destruction.
Over 400 people were injured, with numerous individuals requiring medical attention for serious injuries sustained during the event. Approximately 1,200 homes were destroyed or severely damaged, displacing thousands of residents from their homes. An estimated 2,000 people were displaced, leading to significant humanitarian needs for shelter and assistance.
Secondary Effects:
- Infrastructure Damage: Key roads and bridges were destroyed or blocked, complicating rescue operations and access to affected areas. The local government faced challenges in restoring basic services like electricity and water supply.
- Environmental Impact: The landslide altered local waterways and ecosystems, leading to concerns about future flooding and erosion in the region1.
- Psychosocial Impact: Survivors experienced trauma from losing loved ones and their homes, contributing to long-term mental health challenges within the community.
Causes:
- The primary causes of the Mocoa landslide included:
Heavy Rainfall: A record-breaking rainfall event occurred just before the landslide, with some areas receiving over 300 millimeters (11.8 inches) of rain within a few hours.
- Geological Conditions: Mocoa is situated in a mountainous region with steep slopes that are prone to landslides during heavy rains. Deforestation in the area may have exacerbated vulnerability to such disasters
Summarise the landslide in Guinsaugon in 2006.
- Date: February 17, 2006
- Location: Guinsaugon, Southern Leyte, Philippines
- Deaths: 1,126+
- Injuries: ~30
- Displaced Individuals: ~19,000
- Causes: Heavy rainfall (~1,200 mm), geological instability near Philippine Fault.
Summarise the landslide in Mocoa in 2017.
- Date: April 1, 2017
- Location: Mocoa, Colombia
- Deaths: ~300
- Injuries: 400+
- Displaced Individuals: ~2,000
- Causes: Intense rainfall (>300 mm), steep terrain prone to landslides.
What is the name of the organisation in California that educates citizens about earthquakes?
Shake Out.
How can people retrofit their homes in HICs?
- Extra metal support
- Metal cladding
- Support to foundations
- Brace and bolt raised foundation homes
- Strengthen soft-story walls
- Reinforce post and pier foundation
- Secure chimney
- Secure heavy furniture and appliances
- Install a seismic gas shut-off valve
- Secure water heater
- Make a safe space for during an earthquake
What can be done to prevent landslides and earthquakes?
- Netting on the slopes to catch any debris or rocks
- Technical paper to stabilise
- Adding metal structures to add resistance
- Concrete walls
What can be done for pre-event management of natural hazards?
Geophysical hazards can be prepared for and mitigated through engineering and seismic design. However, this is not always the preferred or most affordable way of mitigating the hazards. In the case of the Guinsaugon landslide, the lowest-cost solution was to relocate the town. This was achieved in the Philippines because Guinsaungnon was just a village of 1,500 people. In the case of Mocoa, the Columbian authorities recognised that relocation was the preferred option but with a population size of 55,000 this is very challenging to achieve. Alternatives to relocation may result in efforts to stabilise the slopes that cause the threat. Slope stabilisation is often a plausible option in localised areas and is certainly adopted in coastal areas but for Macoa the scale of the problem may also be a significant challenge.
Slope Stabilization
The type of mass movement a slope is vulnerable to will depend on the geology and geographical context of the slope. Slope failure may be caused by tectonic fracturing or sediments may be more vulnerable to pore-water pressure. In some cases like in Guinsaugon, cliff failure can be the catalyst for a much greater debris flow that was almost certainly influenced by both the sediment layers of the slope and the amount of rainfall the area had received at the time. Engineering solutions, therefore, have to address the specifics of the slope failure. It may mean that efforts may be put into mitigating the scale of mass movement rather than preventing it all together. The following two diagrams show engineering efforts for landslide reduction and landslide prevention.
Engineering solutions can be designed to reduce and control the impact of a landslide. A slope can be stabilised to some extent through the use of piling. Piling involves drilling supporting rods into the slope to provide increased stability. The wall, revetments and retaining walls are also used to provide additional shear strength to the slope. Note how this shear strength is gained by building support infrastructure at the base of the slope.
A comprehensive network of drainage channels and tunnels and water storage that have been integrated into the slope. This strategy attempts to remove water from the slope altogether and prevent shear force from building up through pore-water pressure. Images of slope drainage schemes are seen in the photos to the right.
There are many other strategies that can be used to prevent or reduce the impacts of mass movements and these can be done at a range of scales as well as in combination with each other, such as completed drainage well (above ground), water being drained from horizontal drains, and horizontal boring underway.
What are all the ways for small scale slope stabilisation?
- Mesh curtains
- A flexible wire mesh is placed over the slope. This prevents small rock-falls from causing damage or harm. - Bench steps
- These acts as steps in the slope and provide protection against rockfall. Some argue they are ugly and look very artificial. - Gabion boxes
- These structures are wire mesh boxes filled with loose rocks. They can be used to provide stability to a slope by providing shear strength to the base. - Soil nails
- This involves drilling steel bars into the slope to provide stability through the strata. - Slope 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.
How can shear stress be removed?
- Anchors
- Piling
- Gabions
- Soil nails
- Retaining walls
- Slope grillage
- Mesh curtains
How to anchors reduce shear stress?
Anchors reduce shear stress in several ways:
- Load Transfer: Anchors transfer loads from structures into the ground, effectively redistributing forces. This helps to manage and reduce the shear stresses acting on the surrounding soil or rock, preventing potential failure.
- Increased Shear Resistance: By providing additional resistance against lateral forces, anchors enhance the overall shear strength of the soil or rock mass. This is particularly important in applications such as slope stabilization and retaining walls.
- Pretensioning: Increasing the pretension force of anchor cables can significantly reduce peak shear loads. The pretension creates initial tension that counteracts shear forces, thereby enhancing stability and reducing displacement under load.
- Shear Stress Distribution: Anchors help distribute shear stress more evenly across the anchorage zone. This reduces peak stress concentrations that could lead to shear failure, particularly in compression-type anchors where stress tends to converge around the bearing body.
- Dowel Action: The interaction between the anchor and the surrounding material can create a dowel effect, where the anchor resists movement through friction and mechanical interlock, further enhancing shear resistance.
- Grouting Effects: Proper grouting around anchors improves the bond between the anchor and surrounding material, increasing shear strength and reducing the likelihood of shear failure at joints 3.
- Dynamic Response: In dynamic loading situations (e.g., earthquakes), anchors provide a stabilizing effect by resisting lateral movements that could increase shear stresses on structures.
By employing these mechanisms, anchors effectively manage and reduce shear stress, contributing to the stability and safety of various engineering applications.
How does piling remove shear stress?
Piling helps manage and reduce shear stress in soil through several mechanisms:
- Load Transfer: Piles transfer loads from structures deep into the ground, effectively distributing the weight over a larger area of soil. This reduces the shear stress on the soil near the surface, minimizing the risk of shear failure.
- Increased Shear Resistance: As piles are driven or drilled into the ground, they create a frictional resistance along their shaft. This friction helps to counteract lateral forces acting on the soil, increasing the overall shear resistance of the surrounding soil mass.
- Soil Confinement: Piles help confine and stabilize the surrounding soil. By providing lateral support, they prevent soil movement and reduce the potential for shear failure along slip planes.
- Reduction of Pore Pressure: During pile installation, negative pore pressures can be generated in saturated soils, which can enhance effective stress and thereby increase shear strength. This mechanism is particularly relevant in saturated sandy soils where pore pressure changes can significantly affect stability.
- Dilation Effects: The installation of piles can induce dilation in surrounding soils, which increases their volume and reduces shear stress on adjacent soil layers. This effect is particularly pronounced in granular soils where particle rearrangement occurs during installation.
- Stabilization of Weak Layers: In cases where weak or liquefiable soils are present, piles can provide stabilization by preventing lateral movement and reducing shear stresses that could lead to failure during seismic events or heavy loading conditions.
- Dynamic Response: Piles can also improve a foundation’s dynamic response to loads such as earthquakes by providing additional stiffness and damping, which helps mitigate shear stresses induced by dynamic loading.
In summary, piling effectively reduces shear stress by transferring loads deeper into the ground, increasing resistance through friction, confining surrounding soil, managing pore pressures, and stabilizing weak layers. These mechanisms enhance overall stability and reduce the likelihood of shear failure in geotechnical applications.
How do gabions remove shear stress?
Gabions help manage and reduce shear stress in several ways:
- Confinement of Materials: Gabions consist of wire mesh baskets filled with rocks or other materials. This confinement prevents the movement of the fill material, which increases the critical shear stress that the structure can withstand compared to loose materials. The mesh holds the stones in place, preventing them from rolling or sliding, which would otherwise contribute to shear failure.
- Increased Shear Resistance: The structure of gabions enhances the overall shear resistance of the soil or slope they are supporting. By providing a solid barrier, they help to resist lateral earth pressures and stabilize the soil behind them, reducing the likelihood of sliding or erosion.
- Load Distribution: Gabions distribute loads over a wider area, which reduces localized stresses that can lead to shear failure. This distribution helps to manage the forces acting on slopes and retaining structures, effectively lowering shear stresses on critical failure planes.
- Hydraulic Resistance: The design of gabions allows for water flow through the rock fill while still providing significant resistance to erosion and shear forces. This hydraulic function helps maintain stability by preventing water from building up behind the structure, which could increase pore water pressure and reduce effective stress.Vegetation Growth: Over time, vegetation can grow within the voids of gabions, further increasing stability and reducing erosion. The roots of plants help bind the soil together, enhancing its shear strength and overall stability.
- Dynamic Response: Gabions can adapt to changes in load and water flow conditions due to their flexible design. This adaptability helps them respond to dynamic forces without failing, maintaining their effectiveness in reducing shear stress over time.
By utilizing these mechanisms, gabions effectively reduce shear stress in slopes and riverbanks, contributing to enhanced stability and erosion control in various civil engineering applications.
How do soil nails remove shear stress?
Soil nails are an effective method for stabilizing slopes and reducing shear stress in soil through several mechanisms:
- Tensile Resistance: Soil nails are typically steel bars that are inserted into pre-drilled holes in the soil or rock. When installed, they act as structural members that resist tensile forces. This tension helps counteract the forces that contribute to slope failure, effectively increasing the overall shear resistance of the soil mass.
- Load Distribution: The interaction between the soil and the nails helps to spread the load throughout the reinforced mass. This redistribution of forces reduces localized stress concentrations that can lead to shear failure.
- Soil Arching: The presence of soil nails induces a phenomenon known as soil arching, where the weight of the soil above is redistributed to adjacent stable areas. This reduces pressure on unstable zones and transfers some of that load to the nails, enhancing their effectiveness in resisting shear stress.
- Increased Shear Strength: By reinforcing the soil, soil nails improve its inherent shear strength. The nails create a composite material effect, where the combination of soil and nail provides greater stability than either would alone.
- Prevention of Slip Surfaces: Soil nails help to stabilize potential slip surfaces within a slope by providing additional resistance against sliding forces. This is particularly important in preventing deep-seated failures, where failure surfaces can extend well below the ground surface.
- Reduction of Shear Forces: As soil nails mobilize their tensile strength, they effectively counterbalance the shear forces acting on a slope. This interaction reduces the overall shear stress experienced by the soil mass, thereby increasing stability.
- Long-Term Stability: Over time, as soil nails become integrated with the surrounding soil, they contribute to long-term slope stability by maintaining their tension and reinforcing the soil structure against future loading conditions.
In summary, soil nails enhance slope stability by providing tensile resistance, redistributing loads, improving shear strength, preventing slip surfaces, and reducing shear forces acting on the slope. These mechanisms work together to create a more stable earth mass capable of withstanding various stresses.
How do retaining walls remove shear stress?
Retaining walls do not directly remove shear stress, but they help manage and redistribute stresses to improve overall stability. Here’s how retaining walls affect shear stress:
- Load distribution: Retaining walls spread the load from the soil mass over a larger area, reducing localized shear stresses.
- Resistance to lateral earth pressure: The wall structure is designed to withstand the lateral earth pressure exerted by the retained soil, effectively transferring these forces and reducing shear stress on the slope.
- Soil confinement: By containing the soil mass, retaining walls help increase the soil’s shear resistance.
- Drainage management: Proper drainage measures in retaining walls prevent the build-up of water pressure, which can reduce effective stress and soil shearing resistance.
- Use of appropriate backfill: Well-graded, compacted backfill materials like selected decomposed granite or rockfill can improve the overall stability and shear strength of the retained soil.
- Structural design: The wall’s stem and footing are designed to resist shear forces, with calculations considering factors such as concrete strength and reinforcement.
While retaining walls don’t eliminate shear stress entirely, they play a crucial role in managing and redistributing stresses to prevent slope failure and improve overall stability.
How does slope grillage remove shear stress?
Slope grillage does not directly remove shear stress, but it helps to manage and redistribute stresses within a slope to improve overall stability. Here’s how slope grillage affects shear stress:
- Load distribution: The grillage structure spreads the load from the soil mass over a larger area, reducing localized shear stresses.
- Reinforcement: Grillage beams provide structural support to the slope surface, helping to resist shear forces that could lead to slope failure.
- Soil confinement: By embedding the grillage into the slope surface (typically 300mm), it helps confine the soil and increases its shear resistance.
- Pressure resistance: The grillage is designed to sustain earth pressures exerted by the slope, effectively transferring these forces to soil nails or other reinforcement elements.
- Prevention of material loss: Grillage coverage (typically 50% or more of the slope surface) helps prevent the loss of loose fill material, which could otherwise reduce shear strength.
- Integration with soil nails: When used in conjunction with soil nails, the grillage transfers forces from the slope surface to the nails, enhancing the overall shear resistance of the system15.
- Minimizing slope movement: In some designs, an embedded concrete footing is used with the grillage to further minimize overall slope movement, which can help maintain shear strength.
While grillage doesn’t directly remove shear stress, it plays a crucial role in managing and redistributing stresses to improve slope stability and prevent failure.
How do mesh curtains remove shear stress?
Mesh curtains do not directly remove shear stress. However, they can help reduce air flow and turbulence near windows, which may indirectly affect shear stress in the following ways:
- Air flow control: Mesh curtains allow some air to pass through while filtering and slowing down the airflow. This can reduce the velocity of air moving past surfaces near the window, potentially decreasing shear stress on those surfaces.
- Diffusion of incoming air: The mesh fabric helps diffuse and spread out incoming air, which can reduce localized areas of high-velocity flow that might create shear stress on nearby objects or surfaces.
- Boundary layer effects: The mesh creates a porous boundary layer that can alter the air flow patterns near the window, potentially reducing shear forces on nearby surfaces.
- Turbulence reduction: By breaking up and slowing down air currents, mesh curtains may help reduce turbulence near the window, which could lower shear stress on surrounding surfaces.
While mesh curtains can influence air flow patterns, they are not specifically designed to remove shear stress. Their primary functions are typically related to light control, privacy, and general air circulation management.
How can water be reduced from land?
- Drainage
- Water storage
- Drainage well
How does drainage reduce water from land?
Drainage systems reduce water from land through several mechanisms:
- Collection and channeling: Drainage systems collect excess surface water and direct it away from waterlogged areas.
- Controlled release: The collected water is channeled to artificial drainage systems or natural watercourses in a controlled manner.
- Infiltration: Some drainage systems, like sustainable urban drainage systems (SuDS), allow water to slowly soak into the ground, mimicking natural drainage processes.
- Storage: Drainage systems often include features like ponds, basins, or water butts that temporarily store excess water.
- Slowing runoff: SuDS and other drainage techniques slow down water runoff, reducing the volume of water that can cause flooding.
- Filtration: Some drainage systems filter the water as it moves through, improving water quality.
- Evapotranspiration: Green drainage solutions, such as rain gardens and green roofs, increase water loss through plant transpiration.
By implementing these various drainage methods, excess water can be effectively managed, reducing waterlogging and flood risks on land.
How does water storage reduce water from land?
Water storage reduces water from land through several mechanisms:
- Collection and containment: Storage facilities like reservoirs, ponds, and tanks collect excess water from rainfall, runoff, and other sources, preventing it from flowing freely across the land.
- Controlled release: These storage systems allow for regulated discharge of water, helping manage flow rates and reduce flooding downstream.
- Infiltration: Some water storage techniques, such as drainage wells and infiltration basins, encourage water to seep into the ground, replenishing aquifers and reducing surface water.
- Evaporation: Open water storage facilities like reservoirs can increase water loss through evaporation, effectively reducing the amount of water on land.
- Temporary flood storage: During extreme events, designated areas can be used to temporarily store flood waters, reducing the risk of flooding elsewhere.
- Soil moisture retention: Certain water harvesting techniques increase soil moisture storage, allowing plants to utilize more water and reducing surface runoff.
Groundwater recharge: Some storage methods actively promote the replenishment of groundwater aquifers, effectively moving water from the surface to subsurface storage
How does a drainage well reduce water from land?
A drainage well reduces water from land through several mechanisms:
- Collection: The well captures excess water from the surface, including runoff from roofs, driveways, and other areas.
- Infiltration: Water enters the well through pipes or perforations in the structure.
- Storage: The well temporarily stores the collected water, often in a large hole filled with gravel or a pre-cast concrete sleeve.
- Percolation: Water slowly seeps through the gravel and surrounding soil, dispersing into the subsoil away from the surface.
- Groundwater recharge: As water percolates, it can replenish aquifers and underground water sources, which is particularly beneficial in water-scarce regions.
This process helps manage stormwater runoff, reduce erosion, prevent flooding, and protect foundations and other structures from water damage8. The effectiveness of a drainage well depends on factors such as soil type, with sandy soils allowing for quicker drainage compared to clay soils.
What are the different stages of hazard management in Park’s Hazard Response Model?
- Search, rescue, and care:
- This stage corresponds to the immediate response after a hazard event. It involves search and rescue operations and providing emergency medical assistance and aid. Quality of life drops significantly during this phase. - Temporary housing and services:
- This stage aligns with the rehabilitation phase in Park’s model. It includes setting up temporary shelters, schools, and restoring basic services. Quality of life begins to improve during this period. - Permanent rebuilding:
- This stage is part of the reconstruction phase in Park’s model. It involves the long-term restoration and rebuilding of infrastructure, aiming to provide the same or improved quality of life compared to pre-disaster conditions.
Additionally, Park’s model includes:
- Pre-disaster equilibrium:
- The normal quality of life before the hazard event
occurs.
- Disaster event:
The point at which the hazard strikes, initiating the
response curve.
What technologies can be used to search for people in a natural hazard?
These include search dogs that are trained to sniff out life beneath the rubble. Dogs can be sent into buildings deemed too unsafe for humans. In addition, life detection units are deployed that involve remotely managed devices that can be pushed into small spaces underneath the rubble. They have sound sensors and cameras with a 90-degree rotation that help recognise signs of life in the tightest of spaces. In the USA, NASA has developed a technology called Finder which uses microwave radar to detect human heartbeats as well as breathing in collapsed buildings. It can detect human life through over 9 metres of rubble and 6 metres of solid concrete, even when the person is unconscious. These devices can be integrated with drones that can fly over collapsed buildings. Global Positioning Systems (GPS) technologies are being developed to enable rescue teams to be tracked whilst searching in large collapsed buildings even when there is no network available.
Explain in detail the aftermath of an earthquake?
In the immediate aftermath of an earthquake, the situation is always chaotic and thwarted with hazards. For many people, an instinct of fight or flight kicks in. Some will run to find shelter and safety and others will immediately take great personal risk to search for trapped people. The extent to which centralised search and rescue will commence early will depend on several factors, including the capacity of the government, its relationship with neighbouring countries and the international community as well as the challenges of accessibility and the degree of remoteness of the area hit.
The speed and effectiveness of search and rescue are critical at this stage. Some more developed governments such as Italy have designated professional agencies that are responsible for leading the response. The Civil Defense in Italy is a national agency with a regional presence made up of permanent professional leaders and thousands of trained volunteers who can mobilise a national response to an earthquake within hours. Less developed countries struggle with capacity and are highly dependent on international responses that inevitably experience a delay. For example in 2010, Haiti had almost no central resources to support search and rescue and to administer an emergency response. Chronic failure in governance was partly to blame in Haiti but also a lack of experience due to infrequent earthquakes and arguably more pressing poverty concerns.
If an organised and centralised response is mobilised lives can be saved. Makeshift outdoor hospitals may be required and temporary shelters can be erected to house the homeless. Search and rescue are critical but can be hampered by frequent aftershocks that can lead to the collapse of partially damaged buildings. Due to these dangers, a number of resources and technologies can be used. These include search dogs that are trained to sniff out life beneath the rubble. Dogs can be sent into buildings deemed too unsafe for humans. In addition, life detection units are deployed that involve remotely managed devices that can be pushed into small spaces underneath the rubble. They have sound sensors and cameras with a 90-degree rotation that help recognise signs of life in the tightest of spaces. In the USA, NASA has developed a technology called Finder which uses microwave radar to detect human heartbeats as well as breathing in collapsed buildings. It can detect human life through over 9 metres of rubble and 6 metres of solid concrete, even when the person is unconscious. These devices can be integrated with drones that can fly over collapsed buildings. Global Positioning Systems (GPS) technologies are being developed to enable rescue teams to be tracked whilst searching in large collapsed buildings even when there is no network available.
Once people are rescued they need a place to go. In some HICs people can often be temporarily housed in hotels and hostels. Large public buildings or travel to stay with family members but there is also a need for temporary shelters. In the absence of a civil defence authority like that in Italy, aid agencies such as the Red Cross and UNICEF will quickly mobilise resources and provide temporary shelter. In the poorest and remotest places, the community also needs to show great resilience and erect shelters of their own. These are built in open spaces away from the dangers of collapsing buildings.
What factors hinder search and rescue?
- Government capacity: wealth, leadership, coordination, availability of trained people (eg. military)
- Relationships: with neighbouring countries and the international community
- Community resilience and cohesion: within the local community, can be highly supportive or rapidly become unsafe
- Timing of the event: night time events are far more challenging
- The magnitude: of the event
- Spatial extent: remoteness and access
- The scale of loss: mega-disasters understandably overwhelm communities
- Secondary hazards: aftershocks, landslides, flooding, tsunamis, and unsafe buildings
- Degree of hazard preparedness: and community perception of risk
Explain how factors influence search and rescue with an example.
Following the L’Aquila earthquake in Italy in 2009, a rapid response was put in place that enabled them to move into the rehabilitation phase in a matter of days not weeks. Thousands of Civil Defence professionals and volunteers descended on the town and planned tent villages were established. These included individual family shelters, kitchen and dining tents, a post office, creche facilities, a clinic and even a temporary school. Italy’s Civil Defence is one of the most experienced and best-resourced hazard response teams in the world. In contrast, In Haiti with 20% of government workers killed and many government and public buildings damaged, people were forced to make shelters themselves, before international teams arrived.
The speed in which a country can move from rehabilitation to recovery depends on many factors. In Haiti, three years after the disaster and despite more than $6 billion in international aid flooding into the country the main public square of the capital Port au Prince was still a tent city. At the time of writing in 2021, many people still live under tarp covers or behind pieces of rusty tin, with no running water, no latrines, no electricity and no security. Some see this as a failure on the part of the international community to respond effectively to major hazards.
Below is a photo that shows tent villages in L’Aquila:
For developed countries, recovery, despite the economic costs being considerably higher, tends to be much faster. In Japan, the economy had completely bounced back within a year of the earthquake and tsunami of 2011. However, HICs tend to face different challenges.
The external agencies that descended on L’Aquila in Italy left local people disempowered. An increased sense of helplessness emerged among the population as outsiders made the decisions. The city was declared a red zone due to the dangerous conditions of many of the buildings and when reconstruction stalled, frustration and public anger grew. People began to see bureaucratic regulations on health safety as a barrier to recovery. On Sundays, the public started illegally entering the city to help with the clear-up. The Italian government rapidly rebuilt apartment blocks on the outskirts of the town. 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. This wasn’t evident in Japan where some of the coastal communities that experienced the tsunami were able to block tsunami wall construction and opted for housing relocation instead.
Essentially the way in which recovery will be established will depend on the priorities of the government. In the case of L’Aquila, in order to restore a sense of normality as quickly as possible in terms of housing, authorities forgot about the importance of community. In fact, the role of local people appeared to have been missed in every aspect of the response to the earthquake. The Japanese recovery showed more insight into the way local people were integrated and empowered in decision-making, although this was not evident in every coastal community. However, it is best illustrated in the settlements that chose not to have a tsunami wall constructed but chose to relocate to the higher ground instead. This way they maintained the identity of their town with its close connection with the sea and it also increased their self-reliance in terms of being able to see the sea and make judgments of their own. Perhaps this is evidence of a broader interpretation of human development. Those settlements that now have 15-metre walls have lost that independence and rely more on the wall doing its job.
What trend are we seeing with technology in post-event management of geophysical hazards?
There is an increasing role for technology in the post-event management of geophysical hazards. Online mapping systems for example are widely used by NGOs and other agencies to help mobilise and organise the logistical operations. These technologies can be integrated with open-sourcing that allows people on the ground to map issues. Open-source mapping technologies empower the public and can help provide them with a legitimate role. By placing data on damage, injuries, suspected trapped people, aid requirements and aid supply into a mapping system, more efficient emergency responses can be achieved as well as avoiding duplication. There are many examples of really well-developed mapping systems that help improve emergency response. Although during the Haiti earthquake when more than twenty countries and over 200 separate agencies sent teams to assist, open source maps were still in their infancy and too many different maps were developed. Rather than reduce duplication of aid they actually provided another example of duplication which increased fragmentation of aid and created a rather confused picture of the emergency responses. These mapping systems are improving all the time and the most effective systems are operated by the major global aid agencies. The following photos show some examples:
Drone use in disaster zones has presented itself as a really useful tool. Not only can they be used to survey damage for rapid assessments that can support search and rescue and rehabilitation but they can also be used long-term to map land use pressures. In Haiti, drones have been used in a project headed by OpenStreetMap Haiti to map the growth and risk factors associated with informal settlement growth following the earthquake. This not only maps the settlements but also helps legitimise them. This could put pressure on the government and international donors to increase investment on improving homes.
How important are relationships with foreign countries and organisations in post-event management strategies?
For example, in the U.S. they have the FEMA (Federal Emergency Management Agency), so if there’s a big hurricane or earthquake they are the ones in charge of organising and coordinating emergency response, so the U.S. are well prepared.
In Haiti, all the organizations that were helping all were doing their search and rescue in the same area. This is why coordination is important to ensure that all affected areas are undergoing search and rescue.
For example, in Myanmar when a geophysical hazard happened, no help was offered by foreign countries because they’re a closed off country.
Having good relations within the community, can allow locating missing people easier and faster. For example, if someone doesn’t see their neighbour, they can tell the authorities.
Spatial extent, remoteness, access is important. Here, in Switzerland, we have helicopters so we can access remote areas. However, countries who don’t, won’t be able to access these areas, and this is where international aid can come in, and helicopters and other resources can be provided.
What challenges can be faced when conducting a search and rescue after a geophysical hazard?
Debris and rubble:
- Large concrete slabs and building materials obstruct access to potential survivors.
- Rescuers must carefully remove debris using heavy machinery, small tools, and sometimes their hands to avoid further harm to trapped individuals3.
- The unstable nature of debris piles poses risks to rescue workers.
Risk of aftershocks:
- Aftershocks can cause already damaged buildings to collapse further, endangering both survivors and rescue teams.
- They may trigger additional hazards like landslides, gas leaks, fires, and rockfalls.
- The constant threat of aftershocks causes significant stress and fear among rescue workers.
Time sensitivity:
- The chances of finding survivors decrease rapidly with time, creating pressure on rescue teams to work quickly.
- International teams often arrive too late to make a significant impact on lives saved.
Locating survivors:
- Identifying voids and spaces where survivors might be trapped requires careful assessment.
- Specialized equipment like life detection units, thermal imaging cameras, and carbon dioxide detectors are needed to locate unconscious or hidden survivors.
Safety of rescuers:
- Unstable structures, hazardous materials, and potential secondary collapses threaten rescuer safety.
- Proper protective equipment and continuous monitoring of building stability are essential
Why are dogs effective for a search and rescue after a geophysical hazard?
- Dogs are highly trained
- Help find survivors
- Because they can smell and reach tight spaces that humans can’t reach
- Aren’t affected by the danger posed by the terrain
- Dogs are determined
- These dogs sense of smells is far greater than their sense of pain
- Searching for these dogs is very difficult and tiring, so must often rotate the dogs and let them rest
What technology was used in Taiwan?
Life Detection Units:
- These units can extend up to 3 meters in length.
- They feature audio-visual capabilities and can rotate, allowing rescuers to see areas that would otherwise be inaccessible.
- The technology requires absolute silence during operation to detect survivors calling for help.
- This technology has contributed to saving many lives during rescue operations.
Earthquake Early Warning (EEW) Systems:
Taiwan operates multiple EEW systems, including:
- The Central Weather Bureau (CWB) regional
warning system
- The National Taiwan University (NTU) P-Alert
system
- The National Center for Research on Earthquake
Engineering (NCREE) on-site system
P-Alert Network:
- Uses low-cost Micro-Electro-Mechanical System (MEMS) sensors.
- Provides on-site warnings and produces shakemaps.
- Can offer 2-8 seconds of warning time in areas close to earthquake epicenters.
Rapid Earthquake Information Release System (RTD):
- Measures and assesses seismic waves quickly.
- Expected to reduce reporting time to 30 seconds by the end of the following year.
What technology was used in the U.S.?
FINDER in the U.S.:
- FINDER (Finding Individuals For Disaster And Emergency Response)
- Technology detects the wavelengths of human heart beats
- This is useful because many victims are unconscious and unable to call for help
- Very lightweight and waterproof
- It can go on a drone, which can scan over the affected areas, which is an efficient way of finding people
Explain the temporary shelter that was provided to citizens in Port au Prince.
Scale of displacement:
- Approximately 450,000 people were living in camps in Port-au-Prince.
- Many families built their own temporary shelters using reclaimed materials from the rubble.
Living conditions:
- People initially slept on sheets and used them to protect themselves from the sun.
- Over time, residents improved their shelters using salvaged materials from the debris.
- Many people lived in dark conditions with limited access to essential services.
Camp environment:
- Camps were filled with children, as schools were shut down.
- People were constantly working to improve their living situations.
- Small businesses emerged within the camps, with people selling items like jewelry and food.
Health concerns:
- Access to medical care was limited or non-existent for many camp residents.
Lack of official support:
- The Haitian government was not actively involved in providing assistance.
- International organizations like the UN and OXFAM were not directly helping with shelter construction.
Explain the camps that were provided for citizens in L’Aquilla.
Scale of displacement:
- Approximately 40,000 people were made homeless by the earthquake.
- Tent camps were established on the outskirts of L’Aquila to house these displaced residents.
Camp facilities:
- The camps included various essential services:
Medical tents for healthcare needs
- Temporary schools to continue education
- Canteens for hot meals
Additional accommodation:
- Besides tent camps, 10,000 people were housed in hotels, particularly along the coast.
- Some train carriages were also used as temporary shelters.
Aid and support:
- The Italian Red Cross provided immediate assistance, including water, hot meals, tents, and blankets.
- A temporary hospital was set up within an hour of the earthquake.
Community spirit:
- Despite the challenging circumstances, there was still a strong sense of community among the survivors.
How are the collaborative maps made and used in search and response?
Maps are made by:
- Map is created by using uploaded texts, tweets, and emails to identify trapped people
- Than circles are placed in areas where the help is needed or where help is taking place
- The circles are proportional to the help needed or that’s taking place
- Maps can also be used to show the series of aftershocks
- Crowdsourcing is how these maps are generated. This is when people volunteer their information.
- Standby task force is the micro mapping platform maps. Often the military uses them to help plan out their response.
Maps are used by:
- The bigger the circle, the more reports have been made in that area
- To identify where the help is
- To identify where help is needed
- Maps that show the series of aftershocks
How is drone mapping useful?
Damage assessment:
- Drones can quickly capture high-resolution aerial imagery to assess building damage.
- This helps identify areas with severe structural damage, allowing rescue teams to prioritize their efforts.
Efficient resource allocation:
- Rapid assessment of affected areas enables emergency responders to make better decisions on resource allocation.
- This information helps aid organizations plan where to focus their rescue efforts first.
Safety and accessibility:
- Drones can access hard-to-reach or dangerous areas without risking human lives.
- They provide a safe way to survey the territory and plan search and rescue operations.
Situational awareness:
- Drone mapping offers real-time imagery, improving overall situational awareness for disaster response teams.
- This comprehensive understanding of the affected area is crucial for effective recovery planning.
What is the old city center of L’Aquilla like one year after the earthquake?
- Ghost town
- Many areas are still off limits
- 308 people killed
- 1,500 were injured
- Lots of buildings are still damaged
What work is going on in L’Aquilla one year after the earthquake?
Ongoing reconstruction:
- Reconstruction was progressing, but at a slow pace. - By 2012, machines and trucks were still removing rubble in some areas.
- The reconstruction process focused on “light damage” repairs first, allowing about 43% of occupants of damaged buildings to return to their homes by December 2010.
Building repairs and assessments:
- Some buildings showed progress in reconstruction, while others remained in the same state as in 2010 or had further deteriorated.
- There was high heterogeneity in building conditions, with some areas having a mix of inhabited houses, houses under reconstruction, and apparently abandoned buildings.
Temporary housing solutions:
- The C.A.S.E. (Complessi Antisismici Sostenibili ed Ecocompatibili) and M.A.P. (Moduli Abitaviti Provvisori) programs had built about 284 housing units in 19 new settlements, accommodating 23,000 survivors.
Gradual return of residents:
- One year after the earthquake, 5,000 people were still in hotels, 15,000 in provisional housing, and 27,000 in rented houses with government grants
What was the impact on the local economy in L’Aquilla one year after the earthquake?
Business closures:
- Many shops and businesses in the city center remained closed.
- Of the 900 local businesses within the walled center at the time of the earthquake, only two dozen had reopened by early 2013.
Job losses:
- Approximately 6,000 jobs were lost as a result of the earthquake.
Reduced economic activity:
- The central business district was largely cordoned off due to unsafe buildings, reducing business activity and tourism.
- Some areas remained designated as “red zones,” further limiting economic recovery.
Housing market disruption:
- Many houses were beyond repair, with damage to between 3,000 and 11,000 buildings.
- The lack of housing led to increased house prices and rents.
Population displacement:
- Around 40,000 people were initially made homeless, with many still living in temporary accommodation a year later.
University impact:
- The number of students at L’Aquila University decreased since the earthquake, affecting the local economy.
What were the frustrations of the local community in L’Aquilla one year after the earthquake?
Slow reconstruction process:
- The reconstruction was perceived as taking too long and progressing too slowly.
- Many residents were still displaced, with 5,000 people in hotels, 15,000 in provisional housing, and 27,000 in rented houses with government grants.
Limited access to homes:
- People wanted access to their homes to retrieve personal belongings and prevent looting.
- Local authorities were attempting to provide controlled access for safety reasons, which caused tension with residents.
Loss of personal memories:
- The inability to access their homes meant that many personal memories associated with these houses were lost or inaccessible.
Inadequate living conditions:
- New settlements lacked essential urban facilities such as churches, schools, pharmacies, and public transport.
- This led to social fragmentation and functional living issues for displaced residents.
Expensive temporary housing solutions:
- The government was spending significant amounts on temporary housing, with monthly grants between €600 and €800 for rented accommodations3.
Slow debris removal:
- Even in 2012, machines and trucks were still removing rubble in some places, indicating poor management of construction and demolition waste.
How many people were still displaced one year after the earthquake in L’Aquilla?
10,000 after a year.
What problems with governance were there one year after the earthquake in L’Aquilla?
Lack of clear communication:
- The communication between local authorities and those affected wasn’t clear, leading to confusion and frustration among residents.
Absence of a clear reconstruction plan:
- Local authorities didn’t have a well-defined plan for reconstruction, hindering the recovery process.
Lack of basic services:
- New settlements lacked essential urban facilities such as churches, schools, pharmacies, and public transport
Misuse of emergency powers:
- Local authorities used emergency powers to manage the disaster context, which led to violations of human rights and hindered community resilience-building.
Slow progress in reconstruction:
- One year after the earthquake, 5,000 people were still in hotels, 15,000 in provisional housing, and 27,000 in rented houses with government grants.
What percentage of the city centre businesses have gone seven years after the earthquake in L’Aquilla?
70% of businesses.
What scandals have occurred seven years after the earthquake occurred in L’Aquilla?
Several scandals emerged in L’Aquila in the years following the 2009 earthquake, particularly related to the reconstruction efforts:
Misuse of EU funds:
- A European Parliament draft report criticized the misuse of EU funds intended for L’Aquila’s reconstruction.
- The EU had released €494 million from its Solidarity Fund for rebuilding efforts.
- Allegations surfaced that some of this money went to contractors with links to organized crime.
Mafia involvement:
- There were serious allegations that part of the reconstruction money was paid to companies with direct or indirect ties to organized crime.
- The Mafia aimed to earn a significant share of the profits from reconstruction efforts.
- Organized crime families, including the Neapolitan Camorra and the Sacra Corona Unita from Apulia, had made inroads into the region.
Corruption and bribery:
- In 2014, L’Aquila’s mayor, Massimo Cialente, resigned amid bribery scandals related to post-quake reconstruction.
- Several officials were accused of accepting bribes to award reconstruction contracts.
Slow and ineffective reconstruction:
- Eight months after the earthquake, rubble was still piled high in the historic center of the city.
- The historic center of L’Aquila remained a ghost town years after the earthquake, with damaged buildings propped up on steel supports
How did the local community feel seven years after the earthquake in L’Aquilla?
Seven years after the earthquake in L’Aquila, the local community experienced significant frustration and disappointment with the recovery process:
Inadequate government response:
- The community felt that more should be done by the government to help, as reconstruction efforts had come to a virtual standstill.
- Many local people believed they were victims not only of the original disaster but also of a failing recovery process.
Lack of concern for well-being:
- There was a perception that the government didn’t care about the community’s well-being1.
- Over 10,000 people were still living in temporary accommodation, highlighting the slow pace of recovery.
Misplaced priorities:
- The community felt that authorities kept focusing on things that often weren’t a priority.
- There was criticism of how funds were used, with temporary accommodation built at 158% of the normal market cost, becoming a permanent liability for the local population.
Desire to leave:
- Approximately 90% of young people expressed a desire to leave L’Aquila, indicating profound dissatisfaction with post-earthquake conditions.
How did the young people feel seven years after the earthquake in L’Aquilla?
Desire to leave:
- A strikingly high percentage of young people, approximately 90%, expressed a desire to leave L’Aquila. This indicates a profound dissatisfaction with the post-earthquake conditions and lack of opportunities in the area.
Lack of activities:
- Young residents felt that there was very little to do in L’Aquila. The limited options for engagement and recreation contributed to a sense of stagnation and boredom among the youth population.
Limited social outlets:
- The primary social activities available to young people were concentrated in cafes and bars. This narrow range of options for socializing and spending time reflects the lack of diverse recreational and cultural opportunities in the recovering city.
Unemployment concerns:
- While not specific to L’Aquila, youth unemployment was a significant issue in Italy during this period. In 2016, the youth unemployment rate in the EU was 18.6%, with Italy having one of the highest rates at 37.8%. This broader economic context likely exacerbated the challenges faced by young people in L’Aquila.
Discuss the role and priorities of community groups versus government agencies in the case of L’Aquila.
Sense of Urgency:
- Community members felt a pressing need for rapid action and recovery, which they perceived was lacking from government agencies. This desire for urgency stemmed from:
- The immediate need for housing and basic services
- Concerns about the long-term economic and social
impacts of delayed reconstruction
Awareness of Corruption:
- Local communities were acutely aware of potential corruption in the recovery process. This perception was fueled by:
- The appointment of Gaetano Fontana, President of
the National Association of Building Firms, as
coordinator of the technical support agency (STM)1
- Allegations of fraud, corruption, and bribery that
led to legal actions following the earthquake
Concerns About Well-being:
- Community members felt that government agencies were not prioritizing their overall well-being. This sentiment was evident in:
- The lack of community engagement in
reconstruction planning
- The implementation of top-down approaches that
ignored local needs and preferences
What was the scale of the aid response in Haiti seven years after the earthquake?
- 316,000 people were killed
- 300,000 buildings were destroyed or damaged
- 1.5 million people were displaced
- 300,000 people were injured
- Morgues were so full, that bodies were left on the street
- 100 countries offered some sort of help (finical aid or help in search and resume)
What criticisms have been charged at aid agencies in Haiti seven years after the earthquake?
- $50 million was raised and given to the Red Cross
- Red Cross was accused of misusing the money given to them
- Accused that they spent money on own internal problems instead of helping in Haiti
- Red Cross reconstructed 7 homes in 7 years
How many people continue to live in temporary homes seven years after the earthquake?
500,000 people.
What caused cholera to return seven years after the earthquake in Haiti?
Hurricane Matthew: In October 2016, Hurricane Matthew struck Haiti, causing severe flooding and infrastructure damage, particularly in the southwestern part of the country48. This natural disaster created favorable conditions for the rapid transmission of cholera by:
- Damaging water and sanitation infrastructure, worsening already poor sanitary conditions.
- Reducing access to safe water, forcing people to rely on contaminated water sources.
- Causing widespread flooding, which facilitated the spread of the cholera bacteria
Inadequate water and sanitation infrastructure: The clean water system was never fully repaired or improved after the 2010 earthquake, leaving Haiti vulnerable to cholera outbreaks6. This ongoing issue is evidenced by:
- The fragile and inferior water and sanitation (WASH) infrastructure that existed before Hurricane Matthew.
- The need for improved WASH infrastructure, which was considered a priority to prevent future outbreaks
What was the impacts of liquefaction on infrastructure in Christchurch?
- 30% of waste water networks sustained damaged
- 50% of roads were damaged
- 15% of water supply was also damaged
- $2 billion is needed and it will take 5 years for a full recovery
- More than 7,0000 houses were put into a residential red zone, which means houses can no longer be built here
What was the role of SCIRT in the recovery plan for Christchurch?
SCIRT (Stronger Christchurch Infrastructure Rebuild Team)
SCIRT was tasked with repairing and reconstructing the horizontal infrastructure damaged during the earthquakes, including water supply networks, wastewater systems, stormwater drainage, and the roading network. SCIRT was a partnership between public and private organizations, formed to efficiently rebuild Christchurch’s infrastructure. It included three government agencies (NZTA, CERA, and Christchurch City Council) and five private contractors (City Care, Downer, Fletchers, Fulton Hogan, and McConnell Dowell). SCIRT adopted a zone-by-zone approach to rebuilding, focusing on specific areas rather than attempting to fix the entire city simultaneously. SCIRT’s work was closely connected with the Land Building and Infrastructure Recovery Plan and informed by the CERA Recovery Strategy and Christchurch Central Recovery Plan. The SCIRT program encompassed hundreds of projects spanning five years, with an initial estimated cost of $2.015 billion, later revised to $2.496 billion.
Discuss the factors you think impact the rate and success of recovery, following geophysical hazard events for the liquefaction of Christchurch?
Factors impacting the rate and success of recovery following geophysical hazard events (Christchurch liquefaction):
Government
- Transparency: The Canterbury Earthquake Recovery Authority (CERA) was established to lead and coordinate recovery efforts, providing clear communication channels.
- Planning: Development of a comprehensive Recovery Strategy to guide reconstruction and rebuilding efforts.
- Amount of funds/aids: The government recognized the enormity of the task and provided significant resources for recovery.
Community:
- Patience: The community faced long-term challenges, with some recovery efforts taking months or even years.
- Cooperation: Volunteer groups like the ‘Farmy-Army’ and ‘Student-Army’ assisted in clean-up efforts.
Technology:
- Modern reconstruction technology: Use of Liquefaction Resistance Index (LRI) mapping to guide rebuilding of pipe networks.
- Quantity and quality of technology: Implementation of ductile materials and flexible pipe systems (PVC and PE pipes) that proved more resilient to damage6.
Infrastructure:
- Prioritization of critical systems: Quick restoration of potable water service compared to wastewater systems.
- Targeted repairs: Focus on repairing and rebuilding horizontal infrastructure (underground pipes, roads, and bridges).
Economic factors:
- Business continuity: Efforts to enable 95% of industry/commercial activity to resume normal business within 3 months.
- Long-term investment: Creation of entities like Regenerate Christchurch and Ōtākaro Limited to oversee long-term development.
Environmental considerations:
- Soil conditions: Recognition of the link between liquefaction severity and infrastructure damage6.
- Adaptation strategies: Development of new design criteria for rebuilding in liquefaction-prone areas6.
Legal framework:
- Special legislation: Passing of the Canterbury Earthquake Recovery Act to facilitate recovery efforts.
- Streamlined processes: Exploration of ways to effectively utilize CERA’s powers for timely, community-supported recovery.
Compare the impacts of the Guinsaugon landslide and the Mocoa landslide
Guinsaugon Landslide:
- Date: February 17, 2006
- Location: Southern Leyte, Philippines
- Primary Trigger: Heavy rainfall (1,200 mm over 10 days)
- Deaths: 1,126+ (potentially up to 2,000)
- Injuries: ~30 reported
- Displaced People: ~19,000
- Buildings Destroyed: 281 houses + school
- Geological Factors: Near Philippine Fault, weak rock formations
- Time of Occurrence: 10:30 AM
- Secondary Effects: Blocked rivers, flooding risks
- Rescue Challenges: No-fly zone, blocked roads
- Long-term Impacts: Psychosocial trauma, community displacement
Mocoa Landslide:
- Date: April 1, 2017
- Location: Mocoa, Colombia
- Primary Trigger: Intense rainfall (300+ mm in hours)
- Deaths: ~300
- Injuries: 400+
- Displaced People: ~2,000
- Buildings Destroyed: ~1,200 homes
- Geological Factors: Steep mountainous terrain
- Time of Occurrence: Early morning hours
- Secondary Effects: Altered waterways, ecosystem damage
- Rescue Challenges: Destroyed infrastructure
- Long-term Impacts: Environmental changes, mental health issues
