How Significant Is the Level of Economic Development When Determining the Impact of an Earth Hazard?
How significant is the level of economic development when determining the impact of an earth hazard ? (30)
Whilst the economic development level of a country is significant in determining the impact of an earth hazard, there are other factors to consider such as: the location of an event or a population centre, the magnitude of an event and other factors such as political relations. These factors shall be examined with reference to earthquake and volcano case studies.
The relationship between the magnitude of an event and its impact is almost implicit. Logically as the magnitude of an event increases so would its effect and yet it is important to analyse this relationship. Both the Richter scale and the VEI index are measured upon a logarithmic scale, meaning that as the value increases by 1 the magnitude increases by ten times. For example an event that is 6.2 on the Richter scale will be ten times stronger than an event that is 5.2. As such as the magnitude increases so too does the effect upon the local area and, if an event is strong enough it can even have a global effect. Mt St Helens erupted in 1982 with a VEI of 5.1 and its local effects were devastating. Over 10,000 tonnes of gas was emitted and tephra was emitted by the volcano which caused localised dimming and an ash plume to rise 22 miles into the sky. The cost to the farming industry was extreme, with the event costing farmers $20 billion and the local lumber trade was decimated with every tree in a 30km radius being flattened.
As seen the effects of an event can be determined by the magnitude of an event, yet the actual human cost in terms of fatalities and displacement was extremely low for the size of the event, with only 57 humans killed. This was because of the location of the event. Due to the event occurring in a national park, there were almost no humans around to be killed or displaced. The effect of the location of a population is shown by the comparison between Mt St Helens and Chaiten. The Chaiten volcano erupted with a VEI of 5.1 , almost identical to the Mt St Helens event, yet due to the close proximity of the population to the volcano the human effects were much more pronounced, with Lahars destroying 3 towns, killing 250 people and displacing over 20,000 people. Yet both Chaiten and Mt St Helens were relatively low on the scale, when the magnitude of an event is large and it occurs in an area with a high population density the effects can be dramatic. The 2013 Nepal earthquake had a magnitude of 8.1 and it hit the densely populated city of Katmandu with a population of 2 million. The death toll was 8,800 and over 450,000 people were displaced, making it the most deadly natural disaster in the countrys history. Worse it yet to come as many geographers believe that in the next 10 years Nepal is likely to experience a million death