Modelling the dynamics of intertidal mudflat and salt marshes within estuaries

The aggregated modelling concept, ASMITA, is used to study gross changes in estuary and tidal inlets over centuries. This paper presents the extension of ASMITA with elements representing salt marshes, where vegetation causes increased sedimentation. First results show that this extension makes ASMITA simulations more realistic, but further validation and calibration against empirical data are required.

The model simulations confirm that channels in estuaries marsh and upper flats will disappear giving an increase in lower flats. This change is partly suppressed by the presence of marsh vegetation. Under high rates of sea level rise salt marshes will drown when the estuary boundaries are constrained (coastal squeeze).