MAPPING FUTURE INTERTIDAL LANDSCAPES THROUGH THE USE OF A SPATIALLY COUPLED VEGETATIVE FEEDBACK MODEL, MEM-2D

Coastal wetlands face an uncertain future from the effects of sea level rise. Predicting the future distributions of these stressed resources is currently a hot topic among researchers who are developing zero-dimensional and spatial models of marshlands. Recent studies challenge current paradigms of marsh stability and suggest marshes stabilize by varying their topography. The wide availability of fine-scale LiDAR, albeit with its known limitations, provides the necessary data to model and map future marshlands and intertidal habitats when linked to vegetative feedbacks and changes in sea level. Here we present MEM-2D, a spatially coupled version of the Marsh Elevation Model. We present results for a modeled 100 year, 1m, SLR event for North Inlet, SC. Habitats of the study area are undisturbed and range from upland longleaf pine savanna to an extensive and stable high salinity marsh-estuary complex dominated by Spartina alterniflora. The system is meso-tidal with an average MHHW of 0.75 m derived from an onsite NOAA tide gauge. Tidal inputs to the system are primarily from near shore coastal water through North Inlet. There is a minor input of tidal brackish water through Winyah Bay to the south. Results indicate that although North Inlet’s saltmarshes are stable in the short term, they will not keep pace with an accelerating SLR and the entire ecosystem will switch from saltmarsh dominance to tidal flat dominance within 100 years.