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| Newly planted trees beside the river Muick, Aberdeenshire © Copyright Gwen and James Anderson and licensed for reuse under this Creative Commons Licence. |
Since Christmas 2013, the UK has experienced the worst
winter weather of the century, with January being the wettest since records
began in 1766. High winds, heavy rainfall and tidal surges have battered the country,
with Western and Southern counties bearing the brunt of the low pressure
systems moving across from the Atlantic Ocean.
Much has been made of the government’s lack of action in
both responding to and preventing flooding in sensitive low-lying areas such as
the Somerset Levels. In particular, many have criticised the Environment Agency
for not spending enough money on hard-defences such as Dykes and the dredging
of river-beds.
Although appropriate in some circumstances, such defences
are often ineffective (and expensive) in the long-term due to the increased threat
from Climate Change. For example, the Holderness coast in the North-east of
Britain, is one of the fastest eroding areas in Europe. On average, two metres of
land is being lost to the sea annually. Placing hard-defences along this long-stretch
of coast would do very little in the way of preventing erosion or protecting
homes from storm-surges. Stormy weather contains high levels of energy and as such,
this energy is often better dissipated through our natural systems.
Models produced by the Forest Research Organisation show
that placing Woodland strategically on a floodplain can significantly reduce
the size and speed of a flood event. This is because trees absorb water and stabilise
the soils. These two effects reduce the size of the flood and also delay the
release of water into the river.
A further study commissioned by The Woodland Trust indicated
that placing tree belts on upland farmland, can mitigate flooding in adjacent
low-lying land, potentially reducing peak stream flow by upto 40%. This is a
significant reduction and highlights the role that Woodland can play in
alleviating future flooding events.
Despite the success of the above studies, it is imperative
that further research is undertaken on how trees and woodland can best reduce
flooding. For instance, one study conducted by the Environment Agency found
that the tactic of damming rivers with trees to prevent flooding in an area was
haphazard and could cause worse flooding downstream, as the water was able to
bypass river-bends and flow through neighbouring fields.
In short, policy-makers must look carefully into the ways in
which Woodland and other natural systems can mitigate flooding. This winter has
demonstrated the variability and strength of Atlantic weather systems. Climate
change is likely to cause more extreme weather and as such, it is important
that the UK puts into practice the most sustainable and effective
flood-management policies. As a result, we will be better prepared and able to
protect the things that are most precious to us; our homes, family and way of
life.
