Towards Water Quality Models [and Discussion]

Predictions of water quality involve the modelling both of physical processes, which underlie the transport and diffusion of all constituents, and of the sources, sinks, partitioning and interactive processes individual to those constituents. These processes are outlined, together with complementary modelling approaches: (i) development of sophisticated three-dimensional models to represent the physics, and sub-models of suspended sediment, microbiology and metal interactions for processes controlling nutrients, dissolved oxygen, phytoplankton, detritus and metals; (ii) a framework to link these component models; (iii) an accessible model with simpler physics for wide use in simulating constituent distributions, for comparison with measurements to infer sources, sinks and interactions. The North Sea Project measurements provide an input in process evaluation, and data to test the models.