Hydrology seeks to understand the movement of water through the environment, and predict how water bodies will behave under different circumstances. At its broadest, it encompasses all aspects of water as it moves through the water cycle, except the ocean phase. Our remit therefore covers changes in water quantities in catchment water bodies. This can include modified or artificial water bodies such as canals and reservoirs and, for SEPA, also includes water movement through groundwater bodies using the knowledge of our hydrogeologists.

In order to make quantitative assessments of water movement we undertake field measurements of rainfall and of loch, groundwater, and river levels – the latter primarily at our network of gauging stations where empirical relationships are developed to convert the level data into flow information. This field data collection is known as hydrometry and is a key source of data for hydrology and hydrogeology both to drive our models and to permit us to undertake other functions – for example, flood risk assessment and flood warning.

SEPA’s hydrology function maintains relationships with key partners throughout the UK including:

• Meteorological Office
• British Geological Survey
• Centre for Ecology and Hydrology
• Hydraulics Research, Wallingford
• Macaulay Land Use Research Institute