World at risk

World at risk

1. Normal Year

   • trade winds move warm surface water towards the western Pacific
     • Cold water wells up along the west coast of S.America (near Peru)
   • Australia (west)
     • S.America (east)
       • high air pressure
         • descending
     • low air pressure
       • ascending

2. el nino year

   • Air pressure over west coast of S.America becomes low and high over northern Australia
     • Normal east to west trade winds over pacific are disrupted (weaken) and warm water 'sloshes' eastwards
       • upwelling of cold water on S.American coast supressed
   • Australia (west)
     • S.America (east)
       • low
         • ascending air (rain clouds above warm water)
           • floods
     • High
       • descending air
         • droughts, fires
   • - rainfall reduced in SE Asia, NZ, Australia - drought, crop failure wildfires
     • - heavy rain Mexico, peru coast - floods and mudslides
       • - suppression of cold current (east pacific) devastates fish catches off west coast S.America
         • -unusually strong winds in Atlantic prevent convection cells forming so fewer severe hurricanes and tornadoes in USA
           • - more cyclones in Hawaii but fewer in N.America
             • - E.Africa floods
               • - S.Africa drought

3. la nina year

   • Air pressure unusually high over west coast of S.America and low over N.Australia
     • easterly trade winds are more intense than normal
       • more warm water pushed to the west of Pacific ocean
   • Australia (west)
     • S.America (east)
       • high
         • descending
           • drought
     • low
       • ascending
         • rain
           • floods
   • - rainfall higher in Indonesia and Philippines
     • - rainfall lower on west coast of S.America
       • - E.Africa, S.America drought
         • - more hurricanes USA

4. Hurricane Jeanne, Haiti, 2004

   • september 2004
     • 3,000 died
       • 250,000 left homeless and starving
         • efforts to get aid to them hampered by remaining floodwaters blocking countries north-south road
   • only category 3 storm
     • only 20 dies in Dominican republic
       • has forest
         • haiti had to deforest for charcoal (affordable fuel)
           • 1950s 25% Now-2%
             • no trees/ topsoil to stop rainwater flooding low lying areas

5. Caribbean storms, 2004

   • Cuba
     • world class meterological institute
       • within 12 hours people can be evacuated to shelters by public transport
         • within 48 hours vulnerable contacted and escape routes planned
           • population educated on hurricane dangers - well organised systems
             • only 4 died during Ivan + Charley
   • Haiti
     • political instability - lack of government organisation
       • extreme poverty - lack of resources (e.g. at national meteorological centre)
         • poor level of education - ineffective communication
           • 3,000 died in Jeanne

6. Disaster Hotspots

   • Philippines
     • Natural Hazards
       • SE Asia - 7,000 islands at latitudes 5-20degrees N of the equator
         • lies in a belt of tropical cyclones (typhoons)
           • dense oceanic Philippines plate being subducted under Eurasian plate - destructive
             • tropical monsoon climate - subject to heavy rainfall - flooding/ mudslides due to deforestation of many hillsides
     • Vulnerability
       • lower middle income country - developing fast
         • lower capacity to cope
           • rapidly increasing young population
             • high average population densities 240 people per km2 - 2000 people per km2 in Manila Megacity
               • many very poor and live on coasts - vulnerable to locally generated tsunamis + typhoon generated storm surges
                 • 10 typhoons each season esp. in Luzon
     • coping
       • Government has established several organisations for:
         • forecasting, warning, hazard risk assessment, disaster training, education
           • e.g. National disaster co-ordinating council
       • land use planning + building regulation
     • Events
       • 1991 volcanic eruption of Mt.Pinatubo - 700 killed
         • Feb 2006 1,126 killed by landslide
           • April 1998 2.5 million affected severely by drought
     • GDP $3,300 pc
   • California
     • Population - 40 million - high income
       • home to megacities e.g. San Francisco, LA
     • Geophysical hazards
       • San Andreas Fault - conservative fault boundary - 2 coastal plates slide past each other at different speeds
         • Soft basin sediments in LA lead to rapid shaking - 5 major earthquakes in last 100yrs - shallow earthquakes more descructive
     • events
       • Loma Prieta earthquake
         • 17 October 1989
           • Magnitude 6.9
             • 63 died
               • 3,757 injured
                 • 10,000 homeless
                   • $10billion propery damage
     • Atmospheric hazards
       • fog, drought, and associated wildfires
         • major impacts from ENSO
           • el nino - floods + landslides
             • la nina - drought + forest fires
       • summer drought
         • problem in Mediterranean climate esp. Southern CA exacerbated by lack of water supplies in LA for rising population
         • Fog and smog
           • Advection fog occurs when cool air (cold offshore current) drifts inland and meets warm air esp. in summer. Climate conditions combine with car pollution to generate photochemical smog which collects in basin
           • Landslides
             • Take place in heavy winter storms where hillsides have been burnt by wildfires and eroded. Coast near Malibu and Santa Monica. Growing risk as climate becomes unpredictable at coasts
     • GDP $47,000 pc

7. History of local hazard events - Shropshire

   • Flooding
     • from major rivers e.g. Severn. Between 1970-2000 flooding was eliminated because of catchment management (dam) in the upper severn. Summer 2007 flash floods (tenbury wells) resulted from torrential rain 20mm in 3 hours. Land slipping along severn gorge
     • Earthquakes
       • 4-5 on richter scale - movement along historic fault lines e.g. Church Stretton Fault. Damage to buildings, minor injuries, no deaths
       • Snowstorms + droughts
         • Continental position within uk leads to harsh winters and severe snowfalls. 1976 heatwave and drought due to anticyclone. March 2007 heavy snowfall for 2 days
         • Storms + droughts
           • violent storms and flash flooding in Tenbury wells (2007). Telford tornado