Physics & Chemistry

The physical and chemical condition of the Scheldt estuary is intensively studied in Flanders and the Netherlands. This condition is closely related to external influences such as climate change and pollution, as well as to morpho- and hydrodynamics and the ecological functioning of the Scheldt estuary.

Water quality is determined by substance flows (exchange of substances through various processes) that occur due to the interaction between the water column and the sediment, the land, the air, and the organisms living there. Parameters used to describe the physical-chemical condition can vary greatly in space and time within an estuary. Therefore, the monitoring of the physical-chemical system includes sampling of the surface water, the water column, and the sediment at different locations in the estuary. Additionally, continuous measurements at fixed stations are combined with periodic surveys. Standard physical parameters such as temperature and salinity are measured, as well as oxygen concentration, light climate, nutrients, and concentrations of substances indicating pollution.

Due to the intense exploitation of the Scheldt and its estuary this watershed has had poor water quality for decades. This has led to a significant decline in the diversity of the plankton, benthos, and fish stocks. In recent years, various efforts have been made to counteract this. For example, more wastewater is being treated, and new mudflat and salt marsh areas, which supply oxygen and filter excess nitrogen from the water, are being created. These efforts have already led to an improvement in water quality and a partial recovery of nature.