SUSTAINABILITY
Changes in weather patterns W
e have always seen a great deal of variability in UK rainfall because our weather patterns
are constantly changing. Despite the current heat wave, four of the top five wettest years have occurred since the last millennium. These extremes are severely affecting the water industry.
Preliminary evidence suggests we are getting slightly more rain in total and it is falling in more intense bursts. A slight increase in UK annual average rainfall of around 2% per decade is apparent, and is consistent with the annual warming trend.
The Met Office’s preliminary research suggests we are getting more rain and we are seeing a change in the nature of the rain we get, with extreme daily rainfall becoming slightly more frequent, most notably during the winter season.
Any changes in the magnitude and seasonality of rainfall will have an impact on river flows and groundwater recharge, and affect water resources. In turn this necessitates effective strategies to deal with the range of impacts - from droughts to floods. Stephen Herndlhofer, manager of risk and analytics at Yorkshire Water, says, “We need to respond with more proactive, integrated and considered mitigation plans, including systems which make more effective use of raw meteorological data.
Our preparations for future events require a greater appreciation of how different weather affects all aspects of the organisation, and what action we need to take to minimise avoidable service failures and associated recovery costs.”
Michelle Spillar
Weather sensitivity analysis One of the impacts that intense bursts of rain cause is increased turbidity which increases the cost of water treatment, which can rise by up to five times.
The Met Office conducted a weather sensitivity analysis for South West Water’s (SWW) treatment works, to establish a relationship between rainfall and high turbidity events and assess and manage the impact of weather on its operations.
Using four years of turbidity data from a remote river monitor, rainfall data from a 5km2 grid over the catchment, and a meteorological station in Cornwall, we were able to establish
More extreme weather conditions and changing weather patterns will impact on the operational and financial performance of the water industry, says Michelle Spillar, head of utilities at the Met Office
a relationship. The results helped us set up a forecast service to enable SWW to keep a close eye on changing events and predict when river conditions will be difficult or expensive to treat. When there is increased probability of difficult conditions, the utility can remotely alter the volumes in the distribution network which supplies its customers enabling them to slow down the production rate at the treatment works. In many cases this avoids the additional filtering all together, or at least reduces the impact significantly. This enables SWW to run its assets more effectively, reducing costs to customers and reducing impacts on the environment.
What does the future hold? The operational and financial performance of a water company is inextricably linked to weather conditions. Recent extremes of weather are already having an impact on the UK water industry’s (water and wastewater) asset serviceability and maintenance, and its long-term strategic planning and investment decisions. Faced with a rising demand for water and a trend for wetter winters, the water industry must act now to prepare for changes in weather patterns. Only through continuing to work with water companies can we at the Met Office provide an understanding that helps the industry explore what to expect from weather conditions now, and how to face them in the future. nnn
water@metoffice.gov.uk
See the Met Office at Sustainable Water 2013 Stand 10
26 Water & Wastewater Treatment August 2013
wwtonline.co.uk
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44