Bluff retreat in North Carolina: harnessing resident and land use professional surveys alongside LiDAR remote sensing and GIS analysis for coastal management insights

Abstract

Bluff landforms, sought-after for housing and development, present a hazard management challenge due to erosional processes despite the perceived safety of elevated land. This study focuses on the Neuse River Estuary in North Carolina, exploring coastal risk perception and erosion. A survey protocol was developed, and questionnaires targeted 246 residents with property within 100 m of the shoreline and 54 land use professionals in Craven County. To explore the connection of individual experiences with erosion, we use openly accessible LiDAR to quantify bluff retreat and erosion between 2014 and 2020, a period that encompasses Hurricane Florence in 2018. Our findings show: 1) survey results reveal a consensus among residents, with 90% observing alterations attributed to storm impacts, 2) preferences for addressing erosion lean towards structural measures, aligning with existing protection strategies (e.g., bulkheads, rip-rap) as opposed to nature-based solutions, 3) bluff tops are eroding at a higher median rate of -0.59 m per year, compared to -0.19 m per year for high sediment banks, and 4) an overall net volume decrease of approximately -1.89 cubic meters per year for Craven County, slightly more than the overall net loss for the Neuse River Estuary, which was -1.74 cubic meters per year. The findings underscore the need for a cohesive bluff erosion management plan, emphasizing the complexity of challenges and the importance of a holistic approach that combines technical studies with effective risk communication.