Physics & Chemistry
The physical and chemical status of the Scheldt estuary are studied intensively in Flanders and the Netherlands. These conditions are closely related to external influences such as climate change and pollution as well as to the morpho- and hydrodynamics and ecological functioning of the Scheldt estuary.
Water quality is determined by substance flows (exchange of substances via various processes) that occur due to the interaction between the water column and bottom, the land, the air, and the organisms within. Parameters used to describe the physical-chemical condition can vary strongly in time and space. Therefore, monitoring the physical-chemical system includes sampling the surface water, the water column, and the bottom on different locations in the estuary. In addition, continuous measurements at stations are combined with measurements of periodic boat trips. Standard physical parameters such as temperature and salinity are measured, but also oxygen concentration, light climate, nutrients and concentrations of substances that indicate pollution.
The Scheldt basin has a poor water quality for decades due to the intense exploitation of the Scheldt and its estuary. This caused a strong decline in plankton, benthos and fish stock diversity. In recent years, various efforts have been made to combat this decline. For example, more wastewater is purified and new mudflats and saltmarshes are created, which supply oxygen and filter an excess of nitrogen out of the water. These efforts have led to a slight improvement of the water quality and restoration of nature.