Background
The increased detection of chemical pollutants within water bodies is leading to greater public concern. In a recent poll, half of the respondents identified "water pollution" as one of their five main environmental concerns (Eurobarometer, 2014).
Unlike flooding problems, water quality failures are often unseen and therefore unreported.
Models that take into account solute mixing processes are vital to predict the concentration and distribution of potentially harmful chemicals and organisms in water networks.
One current example of the relevance of mixing is Metaldehyde, a pesticide applied to protect crops from slugs. During storm events it is washed off as a soluble material and travels via surface water systems into rivers. As a result, short duration spikes of low concentrations have been detected in drinking water supplies (Water UK, 2013).
In addition to the chemical reactions and biological degradation, the timing, concentration and duration of these spikes are governed by the physical mixing mechanisms, with spatial and temporal distributions controlled by physical flow and mixing processes.
The management of water quality in rivers, urban drainage and water supply networks is essential for ecological and human well鈥恇eing.
Professor Ian Guymer
葫芦影业
Predicting the effects of management strategies requires knowledge of the hydrodynamic processes covering spatial scales of a few millimetres (turbulence) to several hundred kilometres (catchments), with a similarly large range of timescales from milliseconds to weeks.
Predicting underlying water quality processes and their human and ecological impact is complicated as they are dependent on contaminant concentration. Current water quality modelling methods range from complex three dimensional computational fluid dynamics (3D CFD) models, for short time and small spatial scales, to one-dimensional (1D) time dependent models, critical for economic, fast, easy鈥恡o鈥恥se applications within highly complex situations in river catchments, water supply and urban drainage systems.
Relevant articles
- Water UK (2013). .
- Eurobarometer (2014). . (Special Eurobarometer 416).