Are the causes of natural disasters always natural?

We hear about them on a regular basis whether it’s a hurricane, flood, volcano or landslide and they are almost always referred to as a natural disaster or a natural event, which makes us feel like we are at the mercy of nature and there is nothing that we could have done to prevent it. but often these events are barely natural at all, and although the initial cause is natural this is sometimes the only natural part of the cause. humans have a bigger impact on the risk of natural disasters and the danger we put ourselves put ourselves in than we have ever thought, me included. until recently I thought of natural disasters as completely uncontrollable but over the course of the past few years studying A level Geography I have been proved wrong. I never realised how much of an impact we have.

hurricane Katrina (photo credit: web.mit.edu)

Most of us will remember Hurricane Katrina that struck New Orleans on 29th August, 2005 because of the severity of the damage it caused. even though it hit a pretty wealthy country, New Orleans was very badly effected, many areas were simply wiped off the map, 1400 people were killed, and at least $75 billion worth of damage. Hurricanes are able to be predicted well these days as was Hurricane Katrina resulting in 350,000 people being evacuated and more leaving in response to hurricane warnings which were released by the US weather service. however, despite this 1400 people still died. so why as New Orleans so badly effected and were humans to blame?

firstly, it could be simply due to the fact that Hurricane Katrina was a very powerful storm. it was the 4th biggest hurricane ever to make landfall in the US, reaching sustained winds of 281 km per hour and gusts of at least 340 km per hour, making it a category 5 storm, the most powerful type of hurricane. this power led to storm surges of at least 9m which was the main cause of damage and death in New Orleans. obviously there are arguments concerning whether the strength of the hurricane could have been influenced by climate change but it is overall a natural case of this disaster, but in my opinion this is as far as the natural causes of the hurricane go.

New Orleans is located in an area that is of high exposure and vulnerability to hurricanes as firstly the population density is very high which increases the risk to life here as there are 12 million people living along the coastal strip between Louisiana and Florida. here the population density is twice the US’ national average. also the coastal wetlands nearby which would naturally reduce the impact of a hurricane by absorbing its energy have been gradually reducing in size over the past few years. this issue was created because the wetlands cannot rebuild themselves as there is not enough sediment reaching them from the Mississippi river as the Mississippi has been lined with concrete and large levees have been built to stop the river from naturally migrating. this has meant that every time there has been a major flood the wetlands have been partly destroyed and are unable to rebuild themselves. therefore the lack of wetlands has increased the vulnerability of flooding when hurricanes do hit. measures have begun to allow the Mississippi to naturally rebuild the wetlands now, but it was too late for New Orleans. therefore this hurricane could have been a man-made disaster as events created by humans have increased the risk of the hurricane, which could have been one of the reasons why so many died.

Also I think it is worth mentioning that New Orleans is not built in the best place for protection from a Hurricane anyway. It is located in the gulf of Mexico which often leads to Hurricanes strengthening due to the shallow waters which cause the water to be warmer. also New Orleans is built-in an area surrounded by several large lakes, the Mississippi river and in an area that is largely below sea level. in some places the city is 8m below sea level. therefore it would be at high risk of any type of flooding, let alone a storm surge from a category 5 hurricane. as a result of hurricane Katrina, it has even been suggested that New Orleans should not be rebuilt, partly due to this reason of it being in such a vulnerable area that if this were to happen again then the damage would be just as bad if not greater, making it not economically viable to rebuild the city.

Map showing New Orleans vulnerability to flooding (photo credit: wikipedia.org)

Perhaps one of the major reasons why New Orleans suffered so badly was the poorly built levee system that was built to stop a storm surge from hurricanes. there are many issues with these levees that were the main contributor, in my opinion, to the damage to New Orleans. firstly, the levees were only  built with to withstand a category 3 storm as it would have cost too much to build a levee system that would withstand anything higher than category 3. however this wasn’t the only problem as it was found, in investigations carried out after the hurricane had hit, that the levees would not have even withstood a category 1 storm as the foundations of the levees were too shallow and were built into clay meaning that the water from the storm surge would first go underneath the levee, undermining it which would have weakened it, before going over the top of it. Therefore it could be said that the damage from the hurricane was caused by the ignorance of humans and their ability to massively underestimate the power of nature. whats more, is that when the levees were rebuilt, they were only rebuilt with a category 3 hurricane in mind, which is a huge mistake if they ever want to prevent the events of 2005 from happening again.

So, as illustrated by the example of Hurricane Katrina, natural disasters can be more human than natural in their causes of damage. there will always be an element of natural cause in a natural disaster, but in a world where human population is rising and putting pressure on people to live in areas that are more of a risk of natural disasters then the cause can be seen to become increasingly human. however, the simple mistake of underestimating the threat that nature can pose, which is  also illustrated by the Vajont dam disaster in Italy, can be a major cause of a natural disaster, making them almost human.

Sources

  • information on Hurricane Katrina 2005 and New Orleans sourced from ‘BBC Horizon- The lost city of New Orleans’ (first broadcast on 2nd Feb 2006) (link to video here) All copyright belongs to the BBC.
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