��«Ӱҵ

Imagine there has been an accidental spill of chemicals in a river, or run-off from a nearby road. There is a growing need to predict concentrations the fate of soluble pollutants once they have entered rivers, as they can impact on the receiving water quality and the ecology.

Natural river bathymetry, combined with the presence of bankside and submerged vegetation creates complex 3D flow fields, restricting the predictive capability of Taylor based longitudinal dispersion coefficients.

The EA Database for Travel Time and Dispersion (Guymer, 2002) collates results from UK river traces. Attempts have been made to relate the longitudinal dispersion coefficient to the properties of the channel, using drainage area, discharge and bed slope. However, the longitudinal dispersion coefficient is poorly predicted based on these easily obtained parameters.

There have been numerous publications relating the longitudinal dispersion coefficient in rivers to the hydraulic and geometric parameters of the flow.

Professor Ian Guymer

��«Ӱҵ

To‐date resource requirements have limited full‐scale river traces to only a few reaches under different flow rates (Wallis and Guymer, 2015).

Work at the University of ��«Ӱҵ is ongoing to record additional full-scale river traces and develop new approaches to describe mixing in rivers and channels.

The main benefits of this research will be the improved representation of transport and mixing of soluble pollutants and microscopic particulates in rivers.

Relevant articles and projects

• Guymer, I. (2002). A national database of travel time, dispersion and methodologies for the protection of river abstractions (PDF, 1.31MB) (Technical Report P346). Environment Agency.
• Wallis, S. G. and Guymer, I. (2015). . Water and Environment Journal, 29(2), 190–201
• Boxall, J. B. and Guymer, I. (2003). . Journal of Hydraulic Engineering, 129(2), 129-139
• Boxall, J. B. and Guymer, I. (2007). . Water Research, 41(2), 341-354.
• The Don catchment
• QUICS