Accretion, retreat and transgression of coastal wetlands experiencing sea-level rise

Abstract. The vulnerability of coastal wetlands to future sea-level rise (SLR) has been extensively studied in recent years, and models wetland evolution have developed assess quantify the expected impacts. Coastal respond SLR by vertical accretion landward migration. Wetlands accrete due their capacity trap sediments incorporate dead leaves, branches, stems roots into soil, they migrate driven preferred inundation conditions terms salinity oxygen availability. Accretion migration strongly interact, both depend on water flow sediment distribution within wetland, so under same external forcing but with different configurations will differently SLR. Analyses response that do not realistic consideration distribution, like bathtub approach, are likely result poor estimates resilience. Here, we investigate how processes affect using a computational framework includes all relevant hydrodynamic transport mechanisms vegetation landscape dynamics, it is efficient enough computationally allow simulation long time periods. Our incorporates two species, mangrove saltmarsh, accounts for effects natural manmade features inner channels, embankments constrictions culverts. We apply our model simplified domains represent four settings found wetlands, including case tidal flat free from obstructions or drainage three other cases incorporating an channel, embankment culvert, combination culvert. use typical south-eastern Australia vegetation, range load, also analyse situations 3 times load potential biophysical feedbacks produce increased rates. find unable cope disappear end century, even load. good improves flushing more resilient than obstacles attenuation can delay submergence 20 years. Results reveal systematic overprediction resilience SLR: half survives while entire