Climate Change, Flooding and Extreme Weather Risk in the United Kingdom

Posted by Alastair Robb on

In recent years the United Kingdom has endured flooding and extreme weather events of notable magnitude. The floods of 2015 caused direct costs of an estimated £ 2 Billion and created untold misery for numerous businesses, livelihoods and communities.  The Government’s National Flood Resilience Review, published in September 2016, acknowledged that further flooding and extreme weather events are likely to occur in the foreseeable future. The Environment Agency identifies that some 5.5 million properties in England and Wales, which equates to broadly one in six properties, are at risk of flooding.

The Committee on Climate Change, an independent, evidence based body, identifies the risk of flooding as the priority for more action to be taken, to achieve higher levels of preparedness. Modelling of rivers and seas and surface water flood risk provide accurate indicative illustrations of flood risk to individual properties, but constant processing of accompanying data sources, such as rainfall intensity and duration is vital.  

Climate change is bringing a warmer world and that means a greater likelihood of hotter, drier summers and warmer, wetter winter months. Modelling by the Meteorological Office suggests that within the summer and winter months, there will also be an increase of 20 to 30% of annual extreme weather events, in particular, short bouts of very high rainfall intensity, which will commonly result in localised surface water flooding incidents. 

Met Office Days of Rain 2015 anomaly from 1981 to 2010

Image 1: Days of rain >= 10mm for 2015, difference from 1981-2010 average. From UK Met Office Report; ‘State of the UK Climate 2015.’

An illustration of the consequences of extreme weather events was provided in the summer of 2016.   A number of areas in the United Kingdom suffered intense, torrential rainfall events, including:

  • Central London - 23rd June 2016, 44.4mm of rain fell, compared to a mean average of 53mm of rainfall in the entire month.
  • Greater Manchester - 13th September 2016, 33.2mm of rain fell in one hour, compared to a mean average of 70mm of rainfall in the entire month.
  • Didcot Train Station - 16th September 2016, 49.3mm of rain fell in four hours, closing the station for over eight hours.

Didcot Train Station 16 September 2016

Image 2: Didcot Train Station flooded by Surface Water on 16th September 2016.

The Public and Private Sector need to invest in suitable resilience measures to mitigate the risks posed by climate change. If it is clearly identified that a critical public transportation node is subject to a specific risk, the public have every right to expect suitable intelligent investment to mitigate the risk. For the Private Sector, risk tolerance and the financial aspects of risk will drive decision making.

Stonehaven Technology