Impacts of Natural Hazards (Edexcel IGCSE Geography)

• In the exam, you may be asked to analyse the short and long-term impacts of an earthquake event. In your answer, you need to consider: Why short and long-term impacts vary - the size and magnitude of the event

• What are the main short and long-term impacts

• How the impacts are affected by the level of development, location and accessibility of the area

• What are the knock-on effects of some impacts e.g. water supplies being contaminated can lead to disease

Tropical cyclone Haiyan

• Name - Haiyan (Yolanda)

• 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

  

Short term impacts

• An estimated 6400 deaths

• Over 4.1 million people 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 with:

  • 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$5.8 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 after in Tacloban access to clean water was still limited

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

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

Mount Merapi eruption

• Name - Mount Merapi

• Location - Java, Indonesia

• Date - 25th October -30th November 2010

• Magnitude - VEI 4

• Plate boundary - Destructive plate boundary where the Indo-Australian plate is subducting below the Eurasian plate

• Type of volcano - Stratovolcano or composite

Short term impacts

• There were 353 deaths and 577 injuries

• Pyroclastic flow travelled 3km 

• Volcanic ash fell up to 480km away

• Over 30cm of ash covered nearby villages including Bronggang 15km from the volcano and Yogyakarta

• The exclusion zone extended to 20km 

• Roads blocked 

• Food prices increase

• Approximately, 350,000 people evacuated

• Schools and airports closed

• Lahars

• Decrease in tourism income

Long term impacts

• The hazard map was updated and the exclusion zone expanded permanently to 2.5km

• 0ver 2,500 residents moved to permanent new homes 

• Money given to farmers by the government to replace livestock and crops

• Improved monitoring 

• Increased education to inform people of what to do and where to go in the event of another eruption

• Dams built to hold back lahars

• Soils will be more fertile due to the minerals contained in the falling ash

Remember, whether you use the case studies here or ones you have completed in class, in the exam you will be expected to know some facts and figures from case studies. These are place-specific details and are what the examiner will be looking for in higher-level answers.