The Impact of Hazards on People and the Environment
The scale of a natural disaster refers to the size of impact on both people and the environment with the latter being of less importance when people are not directly impacted. The map below shows some of the most dangerous places to live. High population densities combined with high seismic disaster suggests the possibility for a future natural disaster.
ACTIVITY
Using the map describe the places most at risk from large natural disaters.
The proximity of people to the epicenter of an earthquake or to a coastal margin in a very high, seismicly active region directly influences the scale of impact. In otherwords if the epicentre of an earthquake hits a megacity the death toll will be huge! The following video from Southern Californian preparedness campaign Shakeout demonstrates the likely impacts of a future earthquake hitting LA.
Using the map describe the places most at risk from large natural disaters.
The proximity of people to the epicenter of an earthquake or to a coastal margin in a very high, seismicly active region directly influences the scale of impact. In otherwords if the epicentre of an earthquake hits a megacity the death toll will be huge! The following video from Southern Californian preparedness campaign Shakeout demonstrates the likely impacts of a future earthquake hitting LA.
However, population density is not the only factor to influence the scale of impact, many other factors play their part. An important factor is the magnitude of the event. How strong was the earthquake or how destructive was the volcano? Again the more powerful the natural disaster the more likely the scale of impact will be larger. I would argue that the proximity to high population density and the magnitude and nature of the event are the most important factors in determining the scale of impact. The 2011 earthquake in Japan is evidence of this. Despite being able to withstand the impacts of seismic waves they were unable to cope with the scale of the tsunami that followed. In total more than 16000 people died.
Another really important factor is the state of development of a country. A developing country is far less resourced to cope with the impacts of a natural disaster in comparison with a developed country. In 2011 Haiti was hit by a 7 richter scale earthquake that claimed the lives of between 230000 and 300000 people. Haiti is one of the least developed countries in the world.
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The following factors all influenced the scale of impact in the Haiti earthquake of 2011. Place them in order of importance using the diamond ranking
Another really important factor is the state of development of a country. A developing country is far less resourced to cope with the impacts of a natural disaster in comparison with a developed country. In 2011 Haiti was hit by a 7 richter scale earthquake that claimed the lives of between 230000 and 300000 people. Haiti is one of the least developed countries in the world.
ACTIVITY
The following factors all influenced the scale of impact in the Haiti earthquake of 2011. Place them in order of importance using the diamond ranking
In comparison New Zealand was hit by a 7.1 earthquake in September 2010. This earthquake's epicenter was not directly within a populated area but it was 40km from the capital city Christchurch, which is home to 4 million people. The staggering difference with this quake was despite it being more powerful not one person died as a direct result of the earthquake. Damage to buildings was also limited.
The main reason for this was the quality of building codes and regulations. Buildings are engineered and built to the highest standards and are built to withstand earthquakes. .
GLOSSARY OF FACTORS INFLUENCING IMPACTS
Natural factors - things like rock type in an earthquake, the shape of a coastline in a tsunami, the height of the land hit by a tsunami can impact the effects. For example, a gently sloping coastline will often suffer more damage than a steep coastline in a hurricane storm surge.
Population density - the greater the number of people in an area the greater the potential for disaster.
Magnitude - the size of the event massively affects the impact it has. Every step up the Earthquake Richter scale represents a 31 fold increase in energy released.
Frequency - how often the hazard occurs. The more often a hazard occurs generally the higher the perception of risk and more prepared people are
Level of development - this determines how much money is available to prepare for the event in advance in terms of predicting the hazard and preparing people to cope with it. Development also determines how weel a country will respond after the event.
Time - the amount of time since the last hazardous event can influence the impact, if a long time goes by people can be unprepared. Also, if the hazard occurs when lots of people are asleep they can also be unprepared.
Preparations - if a place is well prepared regardless of its level of development this can limit the impact of a hazardous event. In India, despite its low level of economic development, rounded wooden houses have been designed to be earthquake proof, thus limiting the impact of these hazards.
Accessibility - if an area is remote or weather conditions and aftershocks prevent safe search and rescue efforts then the impacts can be greatly increased.
ACTIVITY
Produce a mind map of factors influencing the scale of a natural disaster. Use the following headings to structure your map:
Scale and Nature of event, Population, Wealth, Government and Preparedness, Physical environment
The main reason for this was the quality of building codes and regulations. Buildings are engineered and built to the highest standards and are built to withstand earthquakes. .
GLOSSARY OF FACTORS INFLUENCING IMPACTS
Natural factors - things like rock type in an earthquake, the shape of a coastline in a tsunami, the height of the land hit by a tsunami can impact the effects. For example, a gently sloping coastline will often suffer more damage than a steep coastline in a hurricane storm surge.
Population density - the greater the number of people in an area the greater the potential for disaster.
Magnitude - the size of the event massively affects the impact it has. Every step up the Earthquake Richter scale represents a 31 fold increase in energy released.
Frequency - how often the hazard occurs. The more often a hazard occurs generally the higher the perception of risk and more prepared people are
Level of development - this determines how much money is available to prepare for the event in advance in terms of predicting the hazard and preparing people to cope with it. Development also determines how weel a country will respond after the event.
Time - the amount of time since the last hazardous event can influence the impact, if a long time goes by people can be unprepared. Also, if the hazard occurs when lots of people are asleep they can also be unprepared.
Preparations - if a place is well prepared regardless of its level of development this can limit the impact of a hazardous event. In India, despite its low level of economic development, rounded wooden houses have been designed to be earthquake proof, thus limiting the impact of these hazards.
Accessibility - if an area is remote or weather conditions and aftershocks prevent safe search and rescue efforts then the impacts can be greatly increased.
ACTIVITY
Produce a mind map of factors influencing the scale of a natural disaster. Use the following headings to structure your map:
Scale and Nature of event, Population, Wealth, Government and Preparedness, Physical environment
Short and Long Term Impacts
The impacts of natural disasters vary in severity and therefore vary in regard to how long they last. In many ways wealth and development assists in the way people recover from hazards. A more economically developed country can prepare for and predict hazards more effectively and they have many resources to support a faster recovery. However there is also a need for resilience, which means in many developing countries people with experience of hardship can often recover more quickly from hazards. For example following the devestating eruption of Nyirangongo in the Democratic Republic of Congo in 2002, people returned to Goma just two days after lave flow destroyed more than a third of the city. People were recovering what they could and setting up market stalls on dried lava flow.
Impacts of hazards are not so easy to classify as short term and long term as this tends to vary for each individual event. However, the are a number of common long term impacts, which always take time to recover from. These are:
Impacts of hazards are not so easy to classify as short term and long term as this tends to vary for each individual event. However, the are a number of common long term impacts, which always take time to recover from. These are:
- Grief and psychological trauma
- Loss of vital infrastructure, like sewers and sanitation and water
- Loss of power stations and key transport infrastructure, e.g. harbours, airports and railway lines
- Widespread loss of housing
- Loss of a harvest or fertile soils and cattle
- Loss of fishing vessels and equipment
- Loss of forests and freshwater environments
A comparative study of the impacts of tropical storms in one LIC and one HIC
Hurricane Katrina and Cyclone Nargis
It's important when writing a comparison of two events that there are clear points of reference to both events. Always use specific facts that you've learned related to both events and explain the differences. For this part of the course you are expected to make reference to short term and long term impacts of Katrina and Nargis
The following resources describe and explain the impacts of hurricane Katrina and Cyclone Nargis. Most images are hyperlinked to interactive resources and maps.
The following resources describe and explain the impacts of hurricane Katrina and Cyclone Nargis. Most images are hyperlinked to interactive resources and maps.
Cyclone Nargis May 2008
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Hurricane Katrina August 2005
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ACTIVITY Have a go at this 9 card diamond ranking activity courtesy of coolgeography |
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ACTIVITY
Click on the Google Earth image to upload the Google Earth file on Katrina. Use the overlays to explain the the distribution of impacts in New Orleans
Click on the Google Earth image to upload the Google Earth file on Katrina. Use the overlays to explain the the distribution of impacts in New Orleans
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Use the BBC interactive map below to explore, personal stories through individual accounts, photographs and videos showing the longer term impacts of Cyclone Nargis
Use the BBC interactive map below to explore, personal stories through individual accounts, photographs and videos showing the longer term impacts of Cyclone Nargis
Why do people choose to live in hazardous areas?
For me the answer to this question can be summed up in one word; home.
The truth is people are born where they are born and learn life skills that are directly linked to their immediate environment. These life skills are economic and cultural and often linked to the physical and/or human environment. That environment provides for them well, for the majority of the time and natural hazards occur so infrequently that they rarely force to people to reconsider where they live.
ACTIVITY
Study the photographs below and suggest reasons why people live in hazardous regions
The truth is people are born where they are born and learn life skills that are directly linked to their immediate environment. These life skills are economic and cultural and often linked to the physical and/or human environment. That environment provides for them well, for the majority of the time and natural hazards occur so infrequently that they rarely force to people to reconsider where they live.
ACTIVITY
Study the photographs below and suggest reasons why people live in hazardous regions
Because people are born where they are born they adopt the dominant skills for living in that environment, be it fishing or working in industry. Different physical environments offer different natural riches. Coastal areas offer moderate climates and fishing, volcanic environments offer fertile soils and precious minerals. Tourism is also a rapidly growing industry which creates many jobs an geothermal energy can sustain large populations. However home still describes best why people live in hazoudous regions. They are born into a family within a culture and tradition and their ancestors before them did the same. These factors all combine to create a geographical inertia that keeps people where they are born.
However there are also wealth factors that keep people where they are. On the one hand some places like Los Angeles or Tokyo are so developed and offer so many opportunities that people don't want to leave and they even attract more people in. On the other hand poverty traps people in places and prevents them from leaving.
However there are also wealth factors that keep people where they are. On the one hand some places like Los Angeles or Tokyo are so developed and offer so many opportunities that people don't want to leave and they even attract more people in. On the other hand poverty traps people in places and prevents them from leaving.