Exposure of coastal protected areas to storm surge and sea level rise in the United States Mid-Atlantic Bight

Abstract Sea Level Rise (SLR) and storm intensification are a consequence of climate change. As a result, coastal areas are becoming increasingly vulnerable to storm surge exposure. The purpose of this study is to quantify the increased exposure of coastal natural Protected Areas (PA) in the Mid-Atlantic Bight (MAB) region of the United States to hurricane-induced storm surge, particularly when compounded by SLR. In addition, we examined how state-level conservation expenditures align with storm surge exposure, highlighting any correlation between spending and climate-related risks. To estimate the extent of exposure, we used a coupled hydrodynamic-wave model (ADCIRC+SWAN), simulating storm surge under Hurricane Irene (2011) under current and future conditions. We grouped the exposure by both land management and land cover types. The results show that 29.33% of all coastal protected lands were exposed to storm surge under the baseline scenario and increased by 2.97% when 1.3 m of SLR was added. Federal lands experienced the highest exposure, with 49.51%, followed by state-managed lands at 23.36%. Among the land cover types, emergent herbaceous wetlands were the most susceptible, with 76.24% exposed under baseline conditions, and an additional 8.95% increase under the SLR scenario. Moreover, the state conservation expenditure was not proportional to the amount of exposure which suggests a disconnect between funding distribution and exposure pattern to climate-driven coastal flood hazards. We found conservation funding distribution among land managers could be optimized by incorporating local climate change stressors such as future storm surge exposure. Our analysis indicates that current funding allocations do not adequately account for long-term storm surge impacts. This highlights the need for a more climate-informed approach to optimize funding distribution among states.