Quantifying slope across the ecotone as a driver of forest to marsh conversion using geospatial techniques: Application to Chesapeake Bay coastal-plain, USA
Abstract
In response to sea level rise, coastal salt marshes are migrating landward, converting available upland into salt marsh. Conversion of coastal forest to salt marsh is well-documented in the Mid-Atlantic and may offset salt marsh loss due to sea level rise, sediment deficits, and wave erosion. Land slope at the marsh-forest boundary is an important factor determining migration, however, it is impractical to obtain this for the entire bay with solely field measurements. Therefore, we developed a widely applicable method that uses high resolution elevation data and a repurposed shoreline analysis tool to determine slope along the marsh-forest boundary and applied it to the entire Chesapeake Bay coastal-plain. We find that less than 3% of transects across the ecotone have a slope value less than 1%; these low slope environments offer favorable conditions for forest to marsh conversion. Then, we combine the bay-wide slope and elevation data with inundation modeling to determine likelihood of coastal forest conversion to salt marsh. Finally, we investigate geospatial patterns between our predicted areas of high marsh migration potential and previously measured marsh migration rates throughout the Chesapeake Bay coastal-plain. This method can be applied to local and estuary-scale research in the Mid-Atlantic and beyond to support management decisions regarding which forested areas are more critical to preserve as available space for marsh migration.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMOS0090012M
- Keywords:
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- 4321 Climate impact;
- NATURAL HAZARDS;
- 4235 Estuarine processes;
- OCEANOGRAPHY: GENERAL;
- 4534 Hydrodynamic modeling;
- OCEANOGRAPHY: PHYSICAL;
- 4556 Sea level: variations and mean;
- OCEANOGRAPHY: PHYSICAL