Edexcel Unit 1- Going Global (World At Risk)

Hazards

• Geophysical - tectonic/geological events (earthquakes, volcanoesand tsunamis).
• Hydro-meteorological - formed by hydrological (floods) and atmospheric (storms and droughts) processes.
• Context hazard - widespread threats (such as climate change or super volcano)
• Disasters - loss of lives and livelihoods, goods property
• Risk - probability of hazard occuring and becoming a disaster

 Risk (R) = frequency or magnitude of hazard (H) X level of vulnerability (V)

capacity of population to cope and adapt (C)

Why its getting worse?

• Greenhouse effect
• Enhanced greenhouse effect
• Fossil fuels - burning causes carbon dioxide

What could happen?

• Global dimming

Why its the worlds biggest problem?

• Effects everyone
• Chronic (ongoing) hazard
• unpredictable
• Indirect impacts

Trends in number of reported disasters

• Risen sharply since 1960s
• Floods and stroms accounted for 70% of all disasters for last 40 years
• Geophysical have increased slightly
• Biological hazards (bio hazards) - upward trend

Reasons for the increase in disasters

• Global warming
• More disasters may be getting reported than missed

El Nino/La Nina cycle

• Cycle effects winds and ocean currents
• Lasts for 7-10 years
• 1-2 years are El Nino
• 1-2 years are La nino

El Nino

• Very heavy rain in Peru and California
• Dry in Indonesia and Australia  (2006 drought)
• Hurricanes in Atlantic reduced

La Nina

• Very heavy rain in Indonesia and Australia
• Drought in America (Californian drought and wildfires)
• Hurricanes in Atlantic increased

Distribution of Earthquakes

• Clustered on plate boundaries
• Most powerful are destructive of conservative boundaries
• Can trigger tsunamis amd landslides

Destructive- oceanic crust is being subducted beneath a continental plate PHILLIPPINES

(or) Where two collide (shallow intermediate and deep earthquakes)

Constructive- plates are moving apart (large numbers of low-magnitude earthquakes) most under the sea

Conservative - Plates slide past each other (shallow earthquakes high magnitude) SAN ANDREAS FAULT

Distribution of Volcanoes

• Close to plate boundaries

Constructive

• Magma reaches earths surface and wells up (ocean ridges)
• Mid-Atlantic Ridge

Destrictive plate boundaries

• 80% of most active along destructive boundaries (Mt St Helens)
• Ring of Fire Phillippines

Distribution of Slides

Mass movements, such as rock slides, debris flows, snow avalanches and rainfall and earthquake enduced slides.

Landlides

• Seventh biggest killer
• 1400 deaths per year
• Usually in high areas
• Deforestation doesn't help

Snow Avalanches

• Concentrated in high mountain areas such as Alpes of New Zealand
• Tend to occur on slopes above 35 degrees
• Average of 140 deaths a year

Distribution of Drought and flooding

• Effects many people in the world
• Both frequent hazards

Distribution of Storms

Tropical cyclones, mid-lattiude stroms and tornadoes

Hurricanes

• 5-20 degrees north and south of equator
• Tend to move westward
• To form -Sea over 26 degrees  of 70m depth 5 degrees north or south of equator for coriolis effect (rotation of air)

Phillippines

• Lower-middle income country
• 91 million population
• GDP per cpita $5000
• HDI 0.75
• Mountainous country, crowded coastal lowlands
• 7,000 islands very small spread are latitudes between 5 deg. North and 20 deg. South (Typhoon belt)
• Classic hotspot for Typhoons
• Mobile plate boundary
• El Nino/ La Nina cycles increase range of hazards
• Volcanic eruptions explosive with lahars (mudflows)
• Earthquakes are common
• Vulnerability increase by poverty, deforestation, poor land management and rapid urbanisation

California

• Wealthiest state of the USA
• Popluation of 40 million
• GDP per capita $40000
• HDI 0.95
• Major tectonic hotspot (San Andreas fault)
• SUbject to Le Nino/ La Nina
• River floods occur in El Nino years
• Droughts and Wildfires La Nina years
• Fogs occur in San Francisco Bay area
• Landslides frequent
• Coping capacity high
• Economic costs highif disaster strikes in a megacity

Artic Region

• 3-4 degree rise in temperature in the last 50 years
• Melting of Greenland Ice sheet
• Vegetation shifts
• Thawing Permafrost
• Increasing  fires and insects
• Ultraviolet impact
• Carbon Cycle changes

Africa

• Has least contribution to global warming
• Most vulnerable to climate change
• Climate sensitive resources
• Rise in temperature of 3-4 degress prediction
• Water issues
• Food insecurity
• Natural resources Health
• Development of Coastal zones
• Poverty