It would seem that whilst this has been a miserable couple of months on the weather front, the high levels of rainfall echo and possibly outperform similar periods during the winters of 1929-30, 1852/3 and 1876/7 according to the Met office data.
But there are two issues here: the amount of rainfall and the degree of flooding.
Whilst ‘the greater the rainfall, the greater the chance of flooding’ must be true, the actual extent of flooding depends on a range of other factors and key is land use and management. Apparently, as reported in The Guardian, experts from 15 professional bodies have told David Cameron that some of the damage caused by the recent flooding could have been prevented by better planning and land management.
The housing market and poor environmental management
It is reported that the numbers of homes being built in flood risk areas in the face of the Environment Agency’s opposition are increasing markedly. Because of the demand for more housing, developers are seeking to develop estates on land at high risk of flooding. Last year, developers proposed 618 construction projects on land the Agency considered to be particularly high risk, an increase it is reported of more than a third on the previous year.
So this is a Catch 22 situation where a rapidly increasing population demands more homes and permission is granted to build on increasingly marginal sites, so what is the answer? Additionally as houses and accompanying infrastructure are built, more of the land is concreted over which adds to volumes of surface runoff during rainfall events and this increases the likelihood of flooding.
The focus of the Somerset Levels’ flooding is on management practices which have altered in recent years. Historically this area was managed by farmers and engineers, regularly clearing drains and ditches and maintaining the pumping stations. By current accounts these practices have not been pursued in recent years with the well-publicized results ensuing.
So what about Climate Change?
“As yet, there is no definitive answer on the possible contribution of climate change to the recent storminess, rainfall amounts and the consequent flooding. This is in part due to the highly variable nature of UK weather and climate.” As reported in the recent publication from Centre for Ecology and Hydrology (Feb 2014) Recent Storms and Floods in the UK.
Additionally, Mat Collins, a Professor in climate systems at University of Exeter, and a senior adviser for the United Nations Intergovernmental Panel on Climate Change (IPCC) said the storms have been driven by the jet stream (the high-speed current of air that circulates the earth) which has been ‘stuck’ further south than usual.
‘There is no evidence that global warming can cause the jet stream to get stuck in the way it has this winter. If this is due to climate change, it is outside our knowledge,’ he states.
So it seems that the consensus suggests that the storms and the large amount of rainfall are another example of the UK’s very variable weather systems and the extent of flooding due to population pressures and management issues; the climate change and global warming issues appear to be rather a ‘red herring’.
Dr Diana Dine Senior Lecturer (Environmental Chemistry) Institute of Science & the Environment University of Worcester