Hydrology

The UK’s rivers, due to the variability of our climate from year to year and associated extreme weather events, are prone to flooding and periods of drought and water scarcity. Making robust predictions of these impacts is critical to developing effective planning and management of our precious water resources both for now and in the future.

"Water is fundamental to our lives. Not only do we rely on water to sustain our metabolism and for sanitation, but it is essential for almost all of our food production; is a carrier for our waste; maintains a habitat for flora and fauna; supports recreation and enhances the aesthetic value of our landscape. However, to much or too little, at the wrong palace or the wrong time can cause major disruptions to society. In order to support society, water has to be managed in a way that satisfies its multiple users and uses within the constraints of politics and economics."

Long-term records of daily weather variables over the UK since 1962 have been re-processed to produce a 1km gridded meteorological and land state dataset for Great Britain, now publicly available through CEH’s Environmental Information Platform.

The outlook for July is for below normal flows across much of England and Wales, with the possibility of notably low flows in some areas. In north-western areas of the UK including north-west England, July is likely to see normal flows. This pattern is likely to persist over the next three months, although it is likely that river flows will return to normal across Wales. For groundwater, levels in July are most likely to be normal or below normal, and this is likely to continue over the next three months.

The outlook for May suggests normal river flows are likely in northern Britain, and normal to below-normal flows further south. This reflects the notably low April rainfall across England and Wales, with less than half the monthly average received in most areas; however, early May has been very wet in all regions, which decreases the likelihood of very low flows and increases the chances of above-normal flows in the north. The groundwater outlook is for a similar picture to April, with mostly normal and below-normal levels.

Considered at the national scale, weather conditions in February (although exceptionally sunny) were typical of the late winter but the spatial and temporal variations in rainfall amounts were substantial – reflecting the preferred paths taken by the rain-bearing frontal systems. Generally river flows continued their late January recessions during early February with frozen catchments contributing to relatively depressed flow rates.

All indications are that river flows and groundwater levels are most likely to be in the normal range throughout the UK during March.