Living in hazardous areas and the impact of natural hazards

Why do people live in hazardous places?

Reasons for living in hazardous regions

• Billions of people live in areas which are vulnerable to natural events such as earthquakes, volcanic eruptions and tropical cyclones

• It is the interaction between the natural event, humans and the human environment that makes the event a hazard

• There are several reasons why people continue to live in these areas:

  • A lack of education and information means that people are not aware of the risks

  • People believe that the advantages of living in the area outweigh the disadvantages

  • Advantages include:

    • fertile soil in volcanic areas

    • geothermal energy

    • access to water

    • trade

    • jobs

    • tourism

  • People are too poor to move away, they have little choice about where they live

  • People were born in an area and have friends/family there so do not want to move

  • If disasters do not happen frequently people may believe that they are unlikely to be affected

  • Historically settlements have developed in areas on the coast and near rivers which are vulnerable to hazards

What are the short-term impacts of hazards?

Short-term impacts

• Short-term impacts are the things that affect people in the days and weeks after a hazard event

• They include:

  • damage to properties from high wind, heavy rain and storm surges, power cables and telephone lines

  • impact on businesses, tourism and transport

  • landslides

  • deaths and injuries

  • a decrease in quality of life

  • crops destroyed, impacting farmers' incomes and increasing food prices

  • habitat destruction

What are the long-term impacts of hazards?

Long term impacts

• In the months and years after a hazard event there are long-term impacts including:

  • rebuilding of homes, schools, infrastructure and businesses can take time 

  • the cost of rebuilding affects the economy, increases unemployment

  • stricter building codes introduced

  • mental health, Post Traumatic Stress Disorder (PTSD)

  • risk assessments and hazard mapping are reviewed

What were the impacts of a named tropical cyclone?

Typhoon Haiyan

• Name - Haiyan

• Location - Philippines, Vietnam and Taiwan

• Date - November 2013

• Magnitude - Category 5

• Highest wind speed - 315km/h 

• Storm surge - up to 6m

• Rainfall - 282mm in 12 hours

  

  Path of Typhoon Haiyan (Yolanda)

Philippines Facts

• GDP per capita - $2,935

• People live in poverty (less than $2 per day) - 26%

• Access to clean water - 46%

• People per doctor - 1.15 doctors per 1,000 people

Short-term impacts

• An estimated 6400 deaths

• Over 4.1 million people were made homeless

• Almost 90% of Tacloban was destroyed

• Roads blocked by debris and landslides

• Electricity supply was down in some areas for six weeks

• The airport at Tacloban was badly damaged

• Agriculture was affected by:

  • Over 1.1 million tonnes of crops destroyed

  • At least 33 million coconut trees destroyed 

• More than 1.1 million homes were damaged or destroyed

• The cyclone affected 14 million people

• Landslides

Long-term impacts

• The cost totalled US$12 billion

• 'Build Back Better' was launched in 2014 to upgrade buildings to reduce the damage from future tropical cyclones

  • By 2016, only 1% of the target of 200,000 homes had been achieved

• A no-build zone was created along the Eastern Visayas coastline

• A storm surge warning system  was implemented

• Mangroves replanted

• Tropical storm shelters built inland

• One year on, 4 million people were still in temporary shelters

• Six months later, in Tacloban, access to clean water was still limited

What are the impacts of one named volcanic eruption?

Iceland Eruption 2010

Background

• E15 is a small volcano located in the south of Iceland

• Between March and June 2010, it erupte,d producing huge amounts of ash that rose 10,000 m into the air

Causes

• On a constructive plate boundary

• It was covered by a glacier before the eruption, which caused huge amounts of steam as the lava came in contact with the ice

Consequences

Local

• Wind carried much of the ash South away from the most populous areas of Iceland

• Visibility in the local area was poor, and they had to wear goggles and facemasks

• Over 500 farmers and their families had to be evacuated as roads surrounding the volcano were shut down

• The ash contaminated local water supplies, causing farmers to have to bring their livestock inside

• Large floods of water, due to the glacier, swept down the side of the volcano, destroying bridges and roads

International

• After the eruption, there was an 8-day travel ban across much of Eastern and Northern Europe. Around 107,000 flights were cancelled, accounting for 48% of total air traffic and 10 million passengers. Airlines lost $1.2 bn due to the ash

• Food supplies that were normally flown out to locations couldn’t be transported. 20% of the Kenyan economy is based on the export of vegetables and cut flowers to Europe. 50,000 farmers were temporarily unemployed as their produce couldn’t be sold

Short-term responses

• Evacuation of 500 farmers and their families

• People were told to stay inside due to the amount of ash

• No tourists

Long-term impacts

• Further research into the effect of ash on aircraft

• Reconstruction of damaged roads, bridges and local flood defences

• An improved warning system was developed to help predict future eruptions, including greater monitoring of surrounding volcanoes

What are the impacts of two named earthquakes?

Gorkha earthquake

• Name - Gorkha 

• Location - Nepal

• Date - 25th April 2015

• Epicentre - Barpak village, 60km north-west of Kathmandu (capital)

• Depth - 15km

• Magnitude - 7.8

• Plate boundary - Collision plate where Indian plate collides with the Eurasian plate

Landslides triggered by the Gorkha earthquake

Short term impacts

• Approximately 8600 deaths

• Over 19,000 injuries

• Avalanches on Mount Everest and in the Langtang Valley

• Roads blocked due to landslides

• Landslides - village of Ghodatabela covered, leading to 250 deaths

• Over 600,000 houses were destroyed and over 250,000 damaged

• UNESCO World Heritage sites destroyed - Changu Narayan Temple and Dharahara Tower

• Approximately, 8,300 schools were damaged or destroyed

• Over 1,000 health centres destroyed

Long term impacts

• Cost of repairs were over US$10 billion

• Over 7000 schools rebuilt

• Two years later 70% of displaced people are still in temporary shelters

• Stricter building codes introduced - but not always enforced

• Asian Development Bank (ADB) provided a US$3 million grant 

• Grants of US$3000 for people to rebuild homes - Many have not re-paid this 5 years later

Kaikōura earthquake

• Name - Kaikōura

• Location - New Zeland

• Date - 14th November 2016

• Epicentre - 15km north-east of Culverden and 60km south-west of Kaikōura

• Depth - 15km

• Magnitude - 7.8

• Plate boundary - destructive boundary between the Indian-Australian and Pacific plates

Location of the Kaikoura earthquake

Short term impacts

• Two deaths 

• Over 50 people injured

• Temporary homelessness of 60 people

• Over 2000 buildings were damaged or destroyed, including some in the capital city, Wellington

• Power, water and telecommunication cut off to Kaikōura and surrounding communities

• Approximately 11,000 landslides:

  • Destruction of 390km of road and railway

  • Kaikōura and surrounding communities were completely cut off for 16 days

• Uplift of the coastline by 5.5 metres in some areas:

  • Kaikōura's harbour was affected by the uplift, meaning boats could not leave or enter the harbour

  • Disruption of the coastal breeding areas for dolphins, seals and sea birds

• A tsunami followed the earthquake, reaching up to 6.9 metres in Goose Bay

• Insurance costs reached $2.27 billion

• The cost to the government reached almost $3.5 billion

Long term impacts

• Improvements to the tsunami warning procedure 

• Road routes were repaired between one month and one year after the event

• The main rail route reopened after two months but full repair took over a year

• Improvements to the building regulations made to assess existing buildings for earthquake resistance

• Kaikōura's harbour was rebuilt; taking over a year to complete