KATRINA, SANDY AND JOAQUIN
This summer, I visited New York for the first time. A great experience, especially since we got to visit Ellis Island which had just been fully opened to the public after hurricane Sandy damaged it in October 2012. While enjoying the view on Manhattan from the ferry, something struck me. There is literally nothing that protects Manhattan from the sea, except for Battery Park perhaps. And to a Dutch person trained in hydrology, that just does not feel right.
Source: wikipedia
DELTA WORKS
If it weren't for the Dutch, the Netherlands would not exist. We have lived with and against the water for as long as the country exists, have claimed land from the sea and have learned to respect its power. In 1953, the Netherlands faced their last dramatic flooding. The North Sea Flood killed 1,835 people, roughly 70,000 had to be evacuated and I am not even starting to mention the damage the flood cost. The flood resulted in the construction of the Delta Works, an elaborate project to enable emergency closing of the mouths of most estuaries, to prevent flood surges upriver.
The Delta Works are constructed to protect the Netherlands against a 100,000 year flood. In addition, the major sea- and river dykes in the lower part of the country, the ones that protect important areas including The Hague and Rotterdam against flooding, are designed for a 10,000 year flood. The levees protecting the rest of the country from flooding by the big rivers Rhine and Meuse have a once in 1,250 years chance of flooding.
Now, these may sound like rediculously high protection levels, but considering the fact that the Netherlands are so densely populated and the value of the protected land is so high, a major flood is just not a risk the country could afford to take. Or at least, that is what the Dutch think.
NORTH AMERICAN HURRICANES
You can understand my reaction when I learned that only after Katrina struck, the New Orleans levees were raised to protect against a 100 year storm. Raised. Apparently this was an improvement compared to the old situation. In an area that is subsiding, with millions of inhabitants. Seriously? I could not believe that this was all that was done to protect this area with so many inhabitants and with, for example, one of the largest and busiest ports in the world.
The North-Eastern part of the United States is perhaps somewhat less likely to be struck by hurricanes than New Orleans, but it is not uncommon. Hurricane Sandy has shown that a hurricane can cause significant damage to the East Coast. It cost the states of New Jersey, New York and Connecticut a mind blowing 71,4 billion dollar. Hurricane Joaquin is well on its way to be very destructive as well, with rainfall totals ranging from 12 to 24 inches in eastern South Carolina and southeastern North Carolina, which is nearly half of the normal rainfall for an entire year in some areas. Combining this with the fact that many large cities and valuable beachfronts along the East Coast are situated only a meter or two above sea level, often in areas that are subsiding, without much protection from the sea, one can see a recipe for disaster.
Map by XNR Productions/Terra Carta. Originally produced for "Storm of the Century (Every Two Years)" by Mark Fischetti, in Scientific American, June 2013
HURRICANES AND CLIMATE CHANGE
So, are storms like Katrina, Sandy and Joaquin more likely to occur in the future? Scientists from NOAA state that it is premature to conclude that human activity -and particularly greenhouse warming- has already caused a detectable change in Atlantic hurricane activity, but they expect it will have an effect in the future. Other research groups such as Climate Nexus state that because a warmer atmosphere, the result of global warming, holds more moisture in the air, future hurricanes are loaded with more potential for destructive rainfall, already now. In addition, as more sea level rise is expected, these large storm events will with certainty damage assets and people. Even more than they have done so far.
Considering current events and future prospects, to me, it seems inevitable to invest in proper storm and flood protection in these areas. It is too easy to assign the damage only to bad luck or to the effects of climate change; a lot of damage can be prevented by investing in levees, dykes, and other measures of flood and storm protection. Yet, compared to Dutch standards at least, not much has been done to prevent future disasters from happening. This way, today's as well as future Katrina's, Sandies and Joaquins will keep leaving a trail of disaster.