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Factors Affecting the Hazard Risk - Coggle Diagram
Factors Affecting the Hazard Risk
Human Factors
Population density an distribution
Population density is the number of people in an area, while distribution is about where they are
Generally, the greater the number of people in an area, the greater the potential for disaster
Therefore, an earthquake in Alaska will have less impact than one which hits a more densely populated area such as San Francisco
The Pacific Ring of fire covers a 40,000km horseshoe shape and has around 90% of the world's earthquakes and 452 volcanoes, hundreds of millions of people live in this zone
Level of development of the place
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
It also determines how the country RESPONDS after the event, wealthy places tend to respond quicker
HICs generally are much better at preparing and responding to natural hazards because:
Governments
- their governments are often stable and democratic and have lots of agencies that can help during an emergency. Being democratic means that the public can put pressure on the government to have life safe buildings that survive natural disassters, or makes them want to respond quickly as it will help get the politicians votes
Technology
- HICs can afford the technology to help them predict events, they also have the technology to help buildings survive various natural hazards
Planning laws
- many HICs have laws that prevent building in hazardous locations
Agencies
- many HICs have agencies that can act uickly to help people after a disaster, such as a well-equipped army or fire service and experts to coordinate a response in both the short and long term
Management - the 3Ps (Predict, Prepare + Prevent
Predict
- some natural hazards are easier to predict than others, hurricanes can be identified by satellites and then tracked. This allows governments to evacuate if needed
Preparation
- 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
Prevent
- this could be preventing damage to buildings etc. through strict building rules
Education
Regardless of level of development people can be educated to survive natural hazards
Education about the risks of contaminated flood water or earthquakesdrills can save many lives
Physical Factors
Natural factors
Rock type (geology) in an earthquake
The shape of a coastline in a tsunami
The height of the land hit by a tsunami can influence the effects
A gently sloping coastline will often suffer more damage than a steep coastline in a hurricane's storm surge
Generally earthquake shaking in soft sediments is larger and longer than when compared with the shaking experienced at a "hard rock" site
Softer sediments are more likely to liquefy too, which can contribute to building collapse
Magnitude
The size of the event massively affects the impact it has
A hurricane of magnitude 5 on the Saffir Simpson scale will have more impact than that which has a magnitude 3
Every step up the earthquake Richter scale represents a 10 fold increase in damage and a 30 fold increase in energy released
Frequency
This is how often the hazard occurs
The more often a hazard occurs generally the more prepared people are, and the more used to coping they are
Large earthquakes and volcanic eruptions are generally very rare events in terms of a human lifespan, so when they occur they can surprise
Floods are often regular events; large parts of Bangladesh fllood every year. In this event people can adjust their buildings and lives to cope with the risk associated
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 people are asleep, they can be unprepared.
The Christchurch earthquake of 2011 in New Zealand happened during the day when lots of poeple were at work; this contributed to the death toil as many got trapped in collapsed office buildings