Author(s): Schnauder; Bettina Bockelmann
Linked Author(s):
Keywords: Numerical model; Water quality; Nitrogen; Bristol channel; Carmarthen bay
Abstract: The control of nitrogen pollution in coastal waters is a major concern within a sustainable catchment management. The two-dimensional finite volume numerical model HEMAT 2D (Namin et al., 2002) was set up for the Bristol Channel to investigate nitrogen pathways for Carmarthen Bay, Wales, UK. The numerical model implied the momentum and mass conservation equations and the advective-diffusion transport equations. The water quality model at the current stage calculated the four nitrogen fractions organic nitrogen, ammonia, nitrate and nitrite and the concentration of algal biomass. The hydrodynamics were calibrated with tidal current and water level data measured at two locations in the Bay. Water quality samples were taken and analysed by the Environment Agency Wales and used for calibration and verification of the water quality model. The predicted results show very good agreement for the tidal currents and water levels. The nitrogen concentrations are predicted reasonable well with a first default setting of coefficients for the biochemical exchange processes.
Year: 2005