Monday, September 01, 2008

Gustav Looms - Thoughts on the eve of a potential disaster

On August 29, 2005 hurricane Katrina slammed into the gulf coast a bit east of New Orleans and devastated the city along with several other communities in Louisiana, Mississippi and few other southern states. Almost exactly three years to the date, hurricane Gustav... a category 3 hurricane with maximum sustained winds of approximately 115 miles per hour (185 kilometers per hour) is taking aim at the coast of Louisiana, predicted to make landfall slightly to the east of New Orleans.This makes it even worse because this would bring New Orleans into the path of the westward sweeping arms of the hurricane and a predicted 10-14 feet storm surge.

Lets just think about the numbers here before I go into my thoughts about the impending disaster. The density of air (at standard conditions) is about 1.2 kg / cubic meter. Air slamming into 1 square meter of a surface at 185 km/hour will exert a sustained force of ~ 1.59 kN/m^2 which is about 0.23 psi. That sounds awfully small. Assuming that a normal person standing erect has a surface area of about 5 ft^2 facing the wind, it means that (s)he will be subject to a sustained force of 166 lb. (That's almost equal to my own weight slamming into me continuously). Make whatever you will of that small calculation.

As I saw the Katrina disaster unfold three years ago, my thoughts ranged from disbelief to anger to disgust. In my own country - India - which is far poorer than USA, natural disasters claim thousands of lives every year. Almost every monsoon there are disastrous floods along the Gangetic plains. There are occasional cyclones along the east coast. Even now, devastating floods in the state of Bihar are wreaking havoc in countless lives. As ashamed I am of the pathetic response of the governments (both state and central) to natural disasters in my own country, I was even more disappointed at the response to a natural disaster by the governments in THE RICHEST country in the world. I could not believe that all the warnings, studies and predictions were willfully ignored, evacuations were not planned and well executed, safe shelters were not provided to those left behind. None of this was impossible to a country which has landed people on the moon, it was simply not done. Looking back, one could not have expected more from the government of George W. Bush, which can hardly boast of sound planning and foresight as it's forte. To any one who would like to differ, I have a two word response... "Iraq War". On the same note, the response of the Louisiana state government as well was not very well coordinated and executed badly. There is much to be said about the response after the disaster - the search and rescue effort and the recovery efforts - but lets not go into that now.

This time around, things seem different. Mandatory evacuation of New Orleans seems to have worked well ahead of the storm. Residents in the coastal areas have learned their lesson. The levees and other defenses against flooding are probably strengthened too after Katrina. So this storm may not turn out to be such a disaster in terms of loss of human life (Let us all hope so), although disruption of normal life due to property damage may yet be severe and unavoidable.

Human reaction to natural disasters is always quite surprising to me. What makes us rebuild homes on land struck by a huge earthquake? What makes us rebuild houses and schools that were drowned and washed away by a hurricane three years ago? I guess in part, people do it because they don't have a choice. Where else would they go? It's their home, they have lived there their whole life, they have a natural bond with the place. Perhaps a hope too that lightening never strikes the same place twice - which as it turns out is not quite true. This to me is a sign that we as a species are very bad at estimating probabilities. The chance of an earthquake happening in the same place with same intensity in the life time of an average human being is very different that the probability of a hurricane striking a coastal are twice in the life time of an average human being. Yet human response to both disasters can be very similar. Even with full knowledge that disaster may strike them yet again, people go about rebuilding their lives in the same place.

This is OK I guess as long as we learn some lessons from past disasters and use the power of human creativity and imagination to prepare well for future disasters. Building communities in low-lying areas prone to severe flooding for example takes a large investment in building well designed coastal defense system. Such a system is a public good and can be provided most efficiently by government spending. Yet we do not see that kind of investment and planning going into rebuilding of New Orleans. All we have seen so far is more of the same. Natural disasters are unavoidable. Failure to learn from history and a failure of imagination while rebuilding in a disaster prone area is a human created "disaster" that is completely avoidable.

Anyway... I am rambling a bit now. For those who are under Gustav's gun... seek shelter, stay dry and stay safe.