Natural hazards and Disasters

1. Unit III – Chapter 4 Natural hazards and Disasters

2. Floods Earthquakes Hurricanes Tornadoes Volcanoes Tsunamis Avalanches What are they?

3. Aspects of physical world that have potential to cause considerable harm to people • a dormant volcano What is a Natural hazard?

4. When a natural hazard is activated and reacts in such a way as humans and/or communities are destroyed What is a natural disaster?

5. Occur most often in heavily populated areas in southern hemisphere Poorer countries with less solid infrastructure More difficult for poorer countries (LCD and LLCD) to react quickly and compensate for loss Why are Natural Disasters taking a heavier toll these days?

6. Frequency • How often a particular event is likely to occur • Duration • How long an event will last • Extent • How large an area or region will it effect • widespread or restricted to a small area Factors used to C0mpare natural disasters

7. Speed of onset • How much warning will you get • Spatial dispersion • Area affected by disaster – prediction of where it will take place • Temporal spacing • How hazards occur in time – hurricanes occur in the same areas at the same time of year; while volcanoes are unpredictable

8. Loss of life Number of injuries Damage to property Intensity/strength of event wind speed, Richter scale for earthquakes Event causes other hazards – atmospheric, biologic and geologic Classifying natural disasters

9. An event that affects people in many areas of the world An event that has long term effects (for many years) An event that causes permanent damage or serious contamination of the natural environment What is a global hazard?

10. Atmospheric Biological Geological Types of Natural Disasters

11. Atmospheric natural disasters

12. Severe storm Cyclonic storm – hurricane, cyclone, typhoon Tornado Flooding Drought Wildfire Types of Atmosphere hazards/disasters

13. Connected with weather and climate changes normal weather patterns develop because of differences in air masses Prevailing winds shift these air masses When two air masses collide a sharp boundary called a front forms Rotating low pressure areas, or cells form along storm front Depending on how different the air masses are influences the types of storm that will develop Cyclonic storms

14. Develop as the result of high temperatures and large amounts of water vapour Develop over oceans and follow curved storm paths Moved by prevailing winds and the Coriolis effect Usually hit land where they cause significant destruction Tropical cyclones

15. The Hurricane

16. formation of a tornado - Bing Video Tornado

17. Hurricane vs tornado • Form over water • Called hurricanes - Atlantic; cyclones – Indian; typhoons – Pacific • Most destructive of all natural disasters • Follow curved storm paths and often end up over land • Cover extensive areas • High winds, rain • Extensive area so more widespread damage • Form over land • Called twisters, funnel clouds • Occur mostly in middle latitudes with thunderstorms that are part of cyclonic storm forming on cold front • Narrow path • High winds, rain • Limited area so less widespread damage

18. High precipitation associated with a storm front Rivers rise, overflow and flood adjoining lowland Storms can cause “storm surge” which cause extensive lowland flooding Storms can also cause mudslides Floods and Flooding

19. Extended periods without rainfall Prolonged drought – crop failure, death i.e. Sahel area of sub-Saharan region of Africa Desertification = productive dry land is degraded to the point where it is no longer productive drought

20. Dry weather conditions, high winds, large forests are ideal conditions for wildfires Wildfire

21. Biologic natural hazards and disasters Millions of deaths attributed to infectious or parasitic diseases

22. Prior to 2000 – 1.2 million children died/year (textbook) In 2008 - 164 000 measles deaths globally – nearly 450 deaths/day or 18 deaths/hour Measles vaccination (up 72% from 2000) resulted in a 78% drop in measles deaths between 2000 and 2008 worldwide LDCs and LLDCs – 95% of deaths Measles

23. By the end of 2008 - 33.4 million people worldwide were living with HIV 2 million people died of AIDS-related illnesses. Globally, less than 1 in 5 at risk of HIV has access to basic HIV prevention services. Only 36% of people who needed HIV treatment had access to it by end of 2009 2010 report – significant progress is being made HIV

24. HIV/AIDS progress report from 144 low- and middle-income countries in 2009: 15 countries, including Botswana, Guyana and South Africa, were able to treat more than 80% of HIV-positive pregnant women 14 countries, including Brazil, Namibia and Ukraine, provided HIV treatment to more than 80% of HIV-positive children 8 countries, including Cambodia, Cuba and Rwanda, have achieved universal access to antiretroviral treatment (ART) for adults.

25. 35 million people world-wide suffer from disease 140 million African people are at risk caused by a parasitical worm, onchocercavolvulus. The worm larvae are spread by the black simulium fly, which breeds in the high-oxygen water of fast-flowing rivers. fly transmits disease when it bites people, making those who live or work near the rivers vulnerable. Treatment - Mectizan®. River Blindness

26. Ways to break the cycle of infection: reducing # of flies by spraying affected areas with insecticide slowing fast-flowing rivers, making them unattractive as breeding grounds reducing exposure to flies by using protective garments killing the adult worms by removing the worm 'nodules' - difficult because infected villages are often very remote and poor, making accessible surgery difficult. providing a yearly dose of the drug Mectizan® in affected areas. Problems with medication Needs to be administered regularly and communally

27. Geologic hazards and distasters

28. Most violent and sudden Cause the highest # of deaths July 27, 1976 – Tangshan China – killed 255,000 + 665,000 injured Occur in areas of world defined by tectonic plates Many run through highly populated areas Earthquakes

29. Collapsing buildings Breaks in communication and transportation Electricity loss Fire Flooding Disease After Effects

30. High population density Substandard housing Lack relief resources More Severe effects in LDCs and LLDCs

31. Cause fewer deaths than any other natural disaster Slow – lots of warning Well known volcanoes – Mt. Vesuvius (Pompeii), Mt. St. Helens (Washington State), Eyjafjallajökull(Iceland) Hawaii has daily volcanic activity Iceland has harnessed geothermal energy for heating and electricity generation Volcanoes

32. Slide is rapid movement down a slope – rocks, soil or combination Combination of geological factors + triggering event like heavy rain or earthquake or human effect – deforestation, clearcutting Avalanches – rapid movement of snow and ice Slides and Avalanches

33. Japanese for “harbour wave” Not connected to tides – therefore not “tidal waves” Caused by mudflows, landslides, earthquakes or volcanoes that take place on ocean floor Most common cause – earthquakes Devastating tsunami – Thailand, Christmas 2004 – 230,000 deaths Tsunamis

34. We are victims of natural disasters We can also cause them to be more disastrous Clear cutting, hillside farming, urban development The role of humans in natural disasters

35. http://visual.merriam-webster.com/images/plants-gardening/plants/plant/photosynthesis.jpg, retrieved March 1, 2010 http://www.allaboutgemstones.com/rock_cycle.html retrieved March 3, 2010 http://en.wikipedia.org/wiki/Earth March 3 http://www.bing.com/images/search?q=Tide&FORM=BIFD#focal=c753352f665971332d781ca13addc07e&furl=http%3A%2F%2Flibrary.thinkquest.org%2FC003124%2Fimages%2Ftides.jpg March 3 http://www.harcourtschool.com/activity/science_up_close/314/deploy/interface.html March 3 file:///H:\My%20Pictures\Hurricane_formation.gif retrieved March 11 file:///H:\My%20Pictures\flappy_tornado_formation.jpg retrieved March 11 National Geographic websites references