A prevalence of southerly airflows during October 2014 led to a notably mild month in many parts of the UK. Rainfall totals – seven times that for September at the national scale – had a transformative impact on aquifer recharge, river flows, and soil moisture deficits.
The assessment is contained in the latest monthly hydrological summary for the UK, the most authoritative analysis of water resources status in the country. The monthly summaries are produced by the National Hydrological Monitoring Programme, operated by the Centre for Ecology & Hydrology in conjunction with the British Geological Survey.
After a dry September river flows entering October were depressed over wide areas, but from the end of the first week flood alerts became increasingly common. Generally, however, the peak flows were not exceptional and October runoff totals were in the normal range across most of the UK, but substantially above average for many rivers draining the Scottish Highlands.
The seasonally arid soils early in the month were close to saturation by the final week across most western and northern areas but significant soil moisture deficits remain in parts of eastern and central England.
Stocks in most major reservoirs increased appreciably through October and overall stocks for England & Wales were marginally above the late-October average. However, modest declines in stocks were registered for a few impoundments (eg in Yorkshire and Cornwall).
Summary author Jamie Hannaford, from the Centre for Ecology & Hydrology, said, “The spatially very variable October rainfall and soil moisture patterns, together with contrasting aquifer characteristics, made for regional and local variations in recharge amounts through the month, but groundwater levels across the major aquifer outcrop areas are generally within, or above, the normal late-autumn range (often reflecting exceptionally high levels recorded during the late winter).
"Seasonal recoveries in groundwater levels should gather momentum through the late autumn and the general water resources outlook is good.”
The monthly summary is a look back at hydrological events occurring in October 2014. Latest information on flood warnings is provided by the Environment Agency, Natural Resources Wales and Scottish Environment Protection Agency (flood warnings for Northern Ireland are not available).
The latest Hydrological Outlook for the UK will be issued later this week.
The Centre for Ecology & Hydrology jointly operates the National Hydrological Monitoring Programme (for the UK) in conjunction with the British Geological Survey. NHMP scientists produce the UK Monthly Hydrological Summary which assesses rainfall, river flows, groundwater and reservoir levels. They also operate the UK’s National River Flow archive. The NHMP also has a remit to analyse major flood and drought events in the UK and analyse long term trends in UK hydrological data. The UK Monthly Hydrological Summary is published on, or before, the tenth working day, of the following month. A Hydrological Outlook for the UK is also available and is updated monthly.
Details of the National Hydrological Monitoring Programme
Media enquiries related to the Hydrological Summaries should be directed to the CEH Press Office. Our scientists can provide explanation and analysis of historic hydrological patterns, possible future scenarios under climate change and scientific understanding of the current situation. We are not able to comment on immediate operational issues.
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