Author(s): Brian A. Boye; Roger A. Falconer; Kunle Akande
Linked Author(s): Roger Falconer
Keywords: Water quality; Bacterial decay; Longitudinal dispersion; Salinity; Solar radiation
Abstract: This paper reviews the traditional approach of linking models to cover integrated water management from the upper reaches of catchments through river basins, into estuaries and the coastal/marine environment. It highlights some of the deficiencies in the approaches currently being adopted in many non-integrated studies, where artificial boundaries are included in the system and then highlights the need for a more integrated conceptual approach. A case study is discussed, namely the non-compliance of bathing waters along the Ribble Estuary from riverine inputs, with the inputs arising from Waste-water Treatment Works, outfalls and drainage systems. A more integrated approach was applied to this estuary, with refinements to the artificial boundaries. Both hydrodynamic and solute transport processes in 1-D and 2-D domains of this estuary were modelled for a wet event in June 1999. The kinetic decay process representation included the impacts of salinity, solar radiation, turbidity and water temperature. Solutes modelled included faecal coliform, temperature and salinity. From the resulting coliform levels in the integrated model, it was concluded that a better calibration of the model could be obtained by including the effects of cloud cover on decay rates and a more complete inclusion of agricultural or urban run-off. The more integrated approach therefore results in a better inclusion of the physics, giving improved model predictions. Hence better decisions can be made when considering investment strategies, appropriate for various treatment options and solutions in the river basin upstream.