| Abstract: |
It has been the consensus that salinity will increase in the Chesapeake Bay as sea level rises. Potential impacts of salinity change on the local ecosystem are difficult to determine. A three-dimensional hydrodynamic model using the Environmental Fluid Dynamic Code (EFDC) model is developed in this study to simulate the long-term (1998-2008) salinity field in the Bay under a decadal time scale of climate and forcing variability. The model calibration and verification demonstrate that the model is capable of reasonably reproducing the observed salinity structure and long-term trend in the Bay and can be used to study the salinity change under different sea-level rise scenarios. According to the recent U.S. Climate Change Science Program (USEPA, 2009), three future sea-level rise scenarios are selected for this study: (a) the twentieth century rate, which is generally 3 to 4 millimeters per year in the mid-Atlantic region (30 to 40 centimeters total by the year 2100); (b) the twentieth century rate plus 2 millimeters per year acceleration (up to 50 centimeters total by the year 2100); (c) the twentieth century rate plus 7 millimeters per year acceleration (up to 100 centimeters total by the year 2100). Notable changes of salinity are observed in the model simulation with different sea-level rise scenarios. The relationships between magnitude of sea-level rise and salt flux, salt water intrusion intensity, and salinity stratification are investigated. The maximum salinity variation, salinity intrusion, and potential change of accumulative salinity distribution are evaluated based on the model results. |
