Modeling Salinity Response to Relative Sea Level Rise in a Brackish Floodplain Region

Autor: Robert L. Miller
Rok vydání: 2021
Předmět:
Zdroj: Estuaries and Coasts. 45:1270-1286
ISSN: 1559-2731
1559-2723
Popis: A model-based assessment of the response of mean salinities to relative sea level rise (RSLR) in a brackish floodplain region is presented. The study area is located on the Gulf coastal region of Louisiana which is experiencing some of the highest rates of relative sea level rise in the world. A two-dimensional modeling approach is developed, and the local hydrodynamic model is well calibrated for scenario testing purposes. Numerous alternative scenarios of RSLR are evaluated to simulate the salinity response in both the open water and adjacent floodplain areas under a range of wetland roughness and dispersion factors. The analysis reveals key insights on the mean salinity response patterns to RSLR including the sensitivity to deterioration of wetlands and offshore boundary conditions. Also developed are expressions describing the qualitative nonlinear response. A novel partitioning strategy is also employed in the simulation trials to analyze the effect of various accretion deficit scenarios on the nonlinear RSLR-induced salinity response. The analysis shows that the fraction of the floodplain which is able to keep pace with RSLR has an effect an order of magnitude larger than transport parameters associated with marsh deterioration on the RSLR salinity response. Sites exhibiting sustained accretion surpluses over the long term are able to keep pace and would likely contribute to greater overall resilience to future RSLR-induced salinity changes. The robust scenario analysis and findings of this study are widely applicable to the global challenge of managing the effects of RSLR in coastal wetland areas.
Databáze: OpenAIRE