Sunday 27 December 2015

Flooding - thinking like a geographer.....

I have been watching the news today with a mixture of sadness and anger. Sadness that again the lives of so many people have been affected by flooding in such a devastating manner. Anger that the same old platitudes about resilience and reviewing spending on flood defences are being trotted out by politicians. There is much talk of disaster, but it must be remembered that rivers are not doing anything other than what rivers have always done as a natural phenomenon.....flood. They are not the villains of the piece, even if it would be very convenient to portray them as such. Heavy rainfall onto already- saturated soils at a time when the majority of trees are leafless and dormant and hence unable either to intercept rainfall or act as a natural wick sucking moisture from the soil and releasing it back to the atmosphere through transpiration, will always make flooding a likelihood more than a possibility. Natural features such as the permeability of underlying rock and the relief of the land itself can exacerbate the situation, but it is simple....rivers are nature's drains and if they are inundated, they will overflow.
As ever, politicians and the media focus, understandably, on the symptoms rather than the causes of the issue. Again, the talk is of flood defences being inadequate and more money needing to be spent. The Prime Minister is chairing another meeting of Cobra. The news coverage is full of individual heroics and the capacity of the community to rally around... humbling stoicism in the face of adversity. Resigned smiles mask what must be a personal horror. Indeed, amidst all the cost and disruption, the psychological impact of flooding is often overlooked. I recall hearing one flood victim talking about their chronic fear of rain, which is completely understandable and by no means irrational. Two of my dearest friends, both teachers of geography, have been personally affected by the current flooding and it certainly brings home the human tragedy inextricably linked to the news. 
Have we not been here before?  I have heard the word 'unprecedented' several times today....we have not experienced this flooding in a lifetime, the last twenty years....ever. We are again talking about investment in flood defences, which of course must form part of an holistic flood management strategy. But the fundamental truth is that we need to manage our landscapes very differently. It is not simply about assessing risk and playing a kind of Russian roulette with peoples' lives by defending against 'a hundred year event' or some such. It is not about periodicity and probabilities or complex formulae.  It is simple. We need to slow down the speed with which water gets into drainage channels, especially in the upper reaches of a river, and the efficiency of those channels to transport the water itself. Land uses near the source of rivers must be reassessed. Tree planting on a large scale will intercept more rain, but the properties of other vegetation communities such as rough grassland should not be underestimated. In arable areas, the moisture-retaining properties of soil itself need to be improved -  feeding with moisture-retentive humus and avoiding compaction through excessive use of machinery. We are missing an opportunity to create wetlands such as reedbeds and marshes that would not only provide a store for water but rich wildlife habitats. Low-cost sustainable dams made of wood that could slow down the progress of water downstream. There have been fascinating studies of the impact reintroduced beavers have had on the rivers that support them....as natural engineers they have had a positive influence on biodiversity as well as creating temporary storage capacity in mini lakes created by their dams.
In urban areas we need to be creative about the permeability of surfaces for parking, create opportunities for green roofing, design resilience into our homes and above all avoid building either in areas that are prone to flooding or will cause flooding for others downstream. We need houses, of that there is absolutely no doubt. But to build in areas that are sinking (isostacy) on floodplains in the south of England will only lead to future human misery.
My biggest worry is that effective flood management is very difficult to provide in our current political system. Politicians opt for the vote-winning quick fix of flood defences over the longer term strategies required which may take decades to take effect. Climate has always changed. It would actually be news if it didn't. What we need is to cultivate a new relationship with the natural world that is built on an understanding of how it works and is changing rather than the arrogant view that if we throw enough money at an issue we can somehow defend ourselves against it. It is not a war to be won, but a relationship to be mended.

No comments:

Post a Comment

Link to WWT - Welney

Link to WWT - Welney
Some awesome birding opportunities.....