Coastal sand dunes are dynamic structures affected by winds and waves, with processes of sand accretion and erosion often poorly understood. Funded by the National Centers for Coastal Ocean Science, research at Cape Lookout National Seashore, North Carolina, used airborne lidar data over 20 years (1997-2016) to analyze dune changes and develop simplified metrics.
The study highlights three key metrics for understanding dune evolution: (1) total water level impact hours per year, indicating erosion potential; (2) dune building hours per year, representing accretion; and (3) a constructive-destructive dune forcing (CDDF) ratio that captures the net effects of these processes. Findings revealed that while the base of the dune has retreated, crest heights increased by 0.01–0.02 m/year.
Results showed that the first metric explained up to 67% of variance in dune elevation changes. The metrics can help predict which dunes may erode or build, aiding in coastal management and hazard forecasting. This research underscores the need for better understanding coastal processes to improve dune conservation efforts and community preparedness.
Source link
