Managing variability in the face of uncertainty: an example from England

By Sue Tapsell and Prof. Colin Green

colin_greensue_tapsellHappy New Year to our STAR-FLOOD followers!

The 2013 New Year celebrations are now over and we are looking forward to our first complete year of research on the project. However, for many people in England (as well as in other parts of the UK in Scotland, Wales and Northern Ireland) there was nothing to celebrate on New Year’s Eve, as 2012 had seen persistent and widespread flooding with thousands of households and businesses still facing months of distress and recovery efforts. As one national newspaper put it, in 2012 the weather “turned dangerous”. Record rainfall led to widespread flooding affecting every region, taking nine lives and resulting in significant economic and financial losses. Areas once thought to be safe were hit by sudden downpours and rapid runoff. According to official sources, 2012 was unprecedented with regards to the number of weather events resulting in flooding throughout the whole year, with some communities being flooded on multiple occasions. Many emergency response teams were working around the clock and pushed to their limit.

Floods are the product of meteorology times land form; as the latter is modified by land use, rivers are the residual from precipitation.  In England, 2012 started with a drought resulting from two years of below average rainfall and ended as one of the wettest years on record. Soil moisture levels were recorded as 100% across the whole country, resulting in almost any rainfall producing localised or more widespread flooding. In recent history, the climate in the UK has been changeable but inter- and intra-year variability has been low. In 2012, instead of the usual pattern of depressions causing flooding on the major rivers in winter and locally intense summer thunderstorms resulting in flooding on small catchments, flooding occurred across the entire year, with for example, no pronounced wet or dry season; it rained a little bit all the year round.

Part of the explanation for this change has been that the pattern of jet streams has been different from normal and there is evidence that the jet streams in both hemispheres are moving towards the poles. The 2007 summer floods were also ascribed to the position of the jet stream being south of its usual position in summer, so that we experienced what are characteristically winter floods in summer. In addition, the stratospheric temperature has been unusually high and the Meteorological Office reports that this makes weather forecasting beyond a short time horizon very problematic. Taken together, these factors impose severe stress on the flood response capacity of relevant agencies which is usually provided by staff working overtime, shifting staff around, and scheduling leave.  If it is difficult to forecast what the staff demand for the next week will be, it is also difficult to schedule these staff; when floods are constant instead of being unusual, overtime working ceases to be an appropriate adaptation.

Any trend towards greater climate variability will therefore magnify the difficulties of flood risk management in the country and will raise many issues in relation to flood risk management governance. The STAR-FLOOD project has therefore come at an interesting time. Through our country case studies (in England: London and Hull; in Scotland: Glasgow – each of which represents unique flood risk management and governance challenges), we hope to gain a better understanding of what forms of flood risk management strategies will be most successful to increase the resilience of populations to the threat of increased future risk and to suggest which flood risk governance arrangements may be the most appropriate for the diverse physical, social and legal contexts.

Sue Tapsell

Prof. Colin Green