Tidal marsh response to sea level rise: interactions between vegetation die-off, flow and sedimentation.

Tidal marsh ecosystems are threatened by global sea level rise, but have a certain ability to adapt by sedimentation. However, in several tidal marsh areas around the world, the sedimentation rate is slower than the rate of sea level rise, through which the tidal marsh is increasingly flooded, causing stress to the marsh vegetation and eventually resulting in large-scale vegetation die-off. In this project we study the impact of vegetation die-off on the tidal flow and sedimentation patterns in a tidal marsh, which are determinant for the (dis)ability of vegetation recovery. The hypothesis is investigated that a critical tipping point exists, i.e. that there is a critical level of vegetation die-off for which the flow and sedimentation rates are so significantly affected that the conditions for vegetation recovery get worse and worse, leading to a potential runaway feedback to permanent marsh loss. This project quantifies the effects of different spatio-temporal patterns of vegetation die-off on the flow and sedimentation rates in a tidal marsh, through a combination of methods, including remote sensing, hydrodynamic modeling, and field experiments. The project will contribute to new knowledge that can improve predictions of the response of tidal marshes to sea level rise.

Keywords:SPATIAL PATTERN, SEA LEVEL RISE, VEGETATION

Disciplines:Applied mathematics in specific fields, Geology, Geophysics, Physical geography and environmental geoscience, Other earth sciences, Aquatic sciences, challenges and pollution, Geomatic engineering