Differential Impacts & Tectonic Hazard Patterns (Edexcel A Level Geography)

Global disaster trends

• The number of recorded disasters has increased significantly since 1960
• There are a number of reasons for this including:
  • Increased population - the world population has grown from 3 billion to over 8 billion since 1960
    • This means more people are likely to be impacted by any hazard event
    • Increased population density in urban and coastal areas increases the vulnerable population
  • Increased monitoring and reporting means more hazard events are recorded
• Most of the increase has been the result of floods and extreme weather

Recorded global disasters 1900-2022

Tectonic disaster trends 

• The number of tectonic disasters has fluctuated since 1960 but has generally remained steady
• The slight increase in a number of earthquake disasters does not mean there have been more earthquakes or higher magnitude earthquakes. It results from:
  • Greater urbanisation leads to higher population densities and increased building density
  • Population growth means more people are living in earthquake-prone regions

Global tectonic disasters 1900-2022

Number of deaths

• The number of deaths resulting from all hazards has decreased since 1960
• This is the result of:
  • Improved building construction, design and materials 
  • Increased monitoring 
  • Greater preparation and planning - hazard mapping, land use zoning, evacuation planning
  • Education - earthquake drills
  • Improved warning systems 
  • Increased development

Number of deaths from disasters

• The number of deaths from tectonic hazards fluctuates depending on a range of factors including:
  • Magnitude
  • Level of development
  • Location

                                                  1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010  2020

Deaths resulting from tectonic activity

• The impact of a mega-disaster such as the Indian Ocean earthquake and tsunami may skew the overall trend because it leads to so many deaths
• Volcanic eruptions are less frequent than earthquakes and deaths from eruptions are now rare due to improved monitoring, exclusion zones and evacuation plans

Economic cost trends 

• The economic cost of disasters has increased since 1960
  • As countries develop the cost of repairing infrastructure and rebuilding increases 
    • Increased wealth means people have more possessions and property to be damaged and destroyed
    • Infrastructure is more sophisticated and expensive to replace, for example, electric grids 
  • As more people are affected the cost increases

Changes in the global economic cost of disasters 

• The economic impact of disasters is affected by whether the country is developing (LIC) or developed (HIC)
  • The economic cost in US$ tends to be higher in developed countries
  • The impact on the GDP tends to be much greater in developing and emerging countries

Comparison of Costs LIC Vs HIC

Event	Estimated cost (US$)	% GDP
Gorkha earthquake, Nepal (2015)	10 billion	33%
Tohoku earthquake and tsunami, Japan (2011)	360 billion	4%

Accuracy and reliability of data

• The trends associated with all disasters are complex
• They are affected by a wide range of factors
• When disasters occur the data collected may not be accurate due to:
  • The focus when a disaster strikes and in the weeks that follow is on search, rescue and recovery
  • In remote rural areas it may be difficult to collect data

• Tectonic mega-disasters are high impact, high magnitude hazard events which affect several countries either directly or indirectly
• Examples of mega-disasters include:
  • Asian tsunami (2004)
  • Eyjafjallajokull eruption, Iceland (2010)
  • Tohoku earthquake and tsunami, Japan (2011)

Table of Impacts

Event	Impact
Asian tsunami	Affected 18 countries in south-east Asia and Africa Lead to over 225,000 deaths in 12 countries  Indonesia 170,000 deaths Sri Lanka over 35,000 deaths Economic damage of US$10 billion Most of Sri Lanka's fishing boats were destroyed  Tourism was impacted as people were reluctant to visit the areas 17 million people were displaced 90,000 buildings were destroyed in Sri Lanka Severe damage to mangroves and coral reefs
Eyjafjallajokull	20 countries closed their airspace to commercial flights Kenya lost US$1.3 million a day due to cancelled flights for vegetables and flowers 20% of the Kenyan economy relies on exports of vegetables and flowers Airlines lost up to £130 million a day due to cancelled flights Over 100,000 flights were cancelled 10 million travellers were affected 500 farmers evacuated from the area immediately around the volcano Contamination of water sources with fluoride
Tohuku earthquake and tsunami	US$360 billion in economic losses Decrease in industrial production which impacted not only Japan but the many countries which it trades with Shutdown of nuclear reactors meant increasing oil imports and loss of electricity for 4.4 million homes and businesses Radioactive emissions into atmosphere, land and sea Four ports were destroyed and 11 others affected Lead to a stock market crash and negative impact on companies like Sony