Document Type
Article
Department/Program
Virginia Institute of Marine Science
Publication Date
2015
Journal
Geophysical Research Letters
Volume
42
Issue
19
First Page
7992
Last Page
8000
Abstract
Despite the importance of sediment availability on wetland stability, vulnerability assessments seldom consider spatiotemporal variability of sediment transport. Models predict that the maximum rate of sea level rise a marsh can survive is proportional to suspended sediment concentration (SSC) and accretion. In contrast, we find that SSC and accretion are higher in an unstable marsh than in an adjacent stable marsh, suggesting that these metrics cannot describe wetland vulnerability. Therefore, we propose the flood/ebb SSC differential and organic-inorganic suspended sediment ratio as better vulnerability metrics. The unstable marsh favors sediment export (18mgL(-1) higher on ebb tides), while the stable marsh imports sediment (12mgL(-1) higher on flood tides). The organic-inorganic SSC ratio is 84% higher in the unstable marsh, and stable isotopes indicate a source consistent with marsh-derived material. These simple metrics scale with sediment fluxes, integrate spatiotemporal variability, and indicate sediment sources.
DOI
10.1002/2015GL065980
Keywords
Sea-Level Rise; Salt-Marsh; Chesapeake Bay; Tidal Marsh; Brackish Marsh; Estuary; Model; Water; Flux; Accretion
Recommended Citation
Ganju, NK; Kirwan, Matthew L.; Dickhudt, PJ; Guntenspergen, GR; Cahoon, DR; and Kroeger, KD, Sediment transport-based metrics of wetland stability (2015). Geophysical Research Letters, 42(19), 7992-8000.
10.1002/2015GL065980
