IMIS

The recent evolution of habitat area in the Western Scheldt is characterized by a decrease of low dynamic area (e.g. mud flats and shallow water characterized by low physical stress) and an increase of high dynamic area (e.g. deep water and sand flats characterized by high physical stress). Total volume of the channels increased (partly due to dredging) but also the total volume of the tidal flats increased partly by an increase in area, partly by sedimentation. Tidal marshes in the Scheldt estuary rise with rising mean high water level (MHWL), whereby a faster sea level rise will result in a more pronounced elevation difference between levees and adjacent basins (Temmerman et al., 2004a). The marshes are predicted to be able to keep up with the rising MHWL, unless MHWL rise would increase and the suspended matter concentrations would decrease (Temmerman et al., 2004b). This confirms a noted tendency that young marshes accrete to erosion-sensitive high marshes. In the Scheldt young marshes become scarcer.