Posts Tagged ‘Flooding’

Flooding and Climate Change: What have we learned?

February 17, 2014
The River Thames in flood last weekend. As I write, the water level has called by around 20 centimetres.

The River Thames in flood last weekend. As I write, the water level has fallen by around 20 centimetres. What lessons have we learned?

As the flood waters slowly recede, can I be the first to congratulate the Environment Agency?

We have just experienced the worst sequence of weather events for a few decades or a few centuries. And almost nobody was hurt, and only a few thousand houses were flooded. That has to be a pretty good result.

Although these events cannot in any way be linked to Climate Change, there is still a lesson to be learned in that regard: and that is that we are vulnerable.

If the future climate changed so that such weather was more normal – then we would be have to adapt and there would be real costs (financial and otherwise) involved. And if the weather changed more dramatically, then the consequences could easily be more significant.

Now you may think that following Julia Slingo’s comments to the media that there is a link toClimate Change. So I read the Met Office’s 27 page media briefing on ‘the recent storms’ with interest. It reads like a police report of a pub brawl. But instead of:

  • A hit B because B said’s A’s girlfriend was sleeping with C.
  • C screamed and hit A who then attacked D who fell over and hit the bar.

We have:

  • Excess rain in the tropical Pacific affected stratospheric winds
  • These winds made tropospheric storms across North America move southward drawing air from the warm Atlantic etc. etc.

And then after 26 pages the report concludes

… it is not possible, yet, to give a definitive answer on whether climate change has been a contributor or not. 

So let’s put that particular baby to bed: in 30 years time when we look back we will see whether this event was part of a trend or merely a blip – but at this moment, we just don’t know.

And when in 30 years we look back, what will we say?

  • Will we say ‘Thank you’ to ourselves for considering the  possibility that this could be start of a significant change?
  • Will we be grateful to ourselves for updating our flood defences, and adapting our farming and flooding strategies?
  • Will be glad that the extra money we spent saved lives in the many storms which followed?
  • Or will we regret spending the money because – as things turned out – there were no major floods since.
  • Or will we look back and say ‘Great’ we got away with that – we have had 30 years without flooding?
  • Or will we kick ourselves for not acting when we could have done.

Whatever we want to be thinking in 30 years time, we need to act to achieve it now.

The power of water

May 18, 2011
US Army Corp of Engineers Photograph of the Morganza Spillway.

US Army Corp of Engineers Photograph of the Morganza Spillway.

If you ask my advice, there is nothing as nice, as messing about on the river“. And humans have felt that way for a long time. Our settlements have followed river valleys from the mountains out to the sea since the dawn of time. But when the water – either from the river or the sea – wants to be where we happen to live, there is generally only one winner. When disaster strikes people are wont to say that it was unpredictable. However in almost all cases, exactly the opposite is true. These disasters are in fact entirely predictable –  it is just that we have short collective memories. So for example:

  • The tsunami which hit Japan earlier this year , was really only a one-in-one-hundred-year event. How could people have collectively ‘forgotten’ that the sea did this?
  • The flooding in Brisbane last year was entirely predictable, and had happened previously as recently as 1974.
  • Hurricane Katrina’s terrible toll in New Orleans, is really quite understandable in a city which is built below sea level!

And in the face of these disasters I have been extremely impressed by the US handling of the current flooding on the Mississippi – summarised in this Washington Post graphicThe authorities have followed the floods and predicted the extent of the flooding downstream several days in advance. They have destroyed levees to flood farm land rather than cities, and finally opened the splendidly-named Morganza Spillway to successfully prevent flooding in New Orleans. 

The Morganza spillway was envisioned  after the great flooding of 1927, and completed in 1954 in the sure and certain knowledge that at some time in the future there would be another flood that might widen the river to 80 miles across in places. If the Thames flooded like that it would nearly reach the south coast. What I admire is the collective political and engineering understanding that built and maintained this structure through all these years in which it wasn’t needed: it was last opened in 1973. The actions of the engineers have turned flooding from a catastrophe causing loss of life and distressing rescue, into a predictable disaster – the flooding of the surrounding farmlands has been completely predictable giving people many days notice, and allowing them to leave their homes safely.

Reading about the smart flood management, I allowed myself to imagine that the collective might of the US Army Corp of Engineers might deployed to, say, Bangladesh or Pakistan, to wage a ‘War on Water’. Imagine if they constructed dams and levees to protect the country from sea flooding in case of sea level rise. And created designated  flooding areas to manage floods from extreme rains or melting. It might cost a few billion dollars, but the benefits would last for a century or more. Giving people plenty of time to do all the things we love to do by the riverside.

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