Quantifying the Impacts of Storm Surge, Sea Level Rise, and Potential Reduction and Changes in Wetlands in Coastal Areas of the Chesapeake Bay Region

Along the North Atlantic coasts of the United States, sea levels are rising at higher rates than the global average. Additionally, sea level rise (SLR) can cause reduction and redistribution of wetlands across the low-lying coastal landscape. This study applied a coupled storm surge and waves model to the Chesapeake Bay regions that are prone to SLR. Two historical storms of low and high wind intensity were simulated for current and potential future sea-level and land cover conditions. The future scenarios incorporated projections of local SLR and land use due to potential reduction and changes in coastal wetlands. Simulated flood depths were used in depth-damage functions to estimate prospective property damages, and were combined with population density information to estimate potential number of people at risk. The results showed that, depending on storm intensity, the total flooded area can increase from the baseline by 1.3-2.3 times in the minimum SLR scenario, and by 2.1-4.7 times in the maximum SLR scenario. The maximum SLR was estimated to cause approximately $5.8 billion to $8.6 billion in additional damages and potentially to affect 1-1.2 million people more than the number affected in current conditions. Results also suggest that the low-intensity storm was projected to have greater impacts in the future than the high-intensity storm today, indicating that even relatively weak storms may cause considerable damage to coastal communities in a future with SLR. Finally, flooding, property damage, and the number of people affected in the future scenarios were exacerbated by wetlands reduction and change-in other words, the protective services currently provided by natural lands in coastal areas can be diminished in the future with SLR.