FOREDUNE CLASSIFICATION AND STORM RESPONSE: AUTOMATED ANALYSIS OF TERRESTRIAL LIDAR DEMS

: Accurate predictions of foredune response and recovery to storms arecritical for understanding coastal vulnerability at a variety of time-scales. Foredunemorphology and storm response were investigated using terrestrial lidar data along a10-kilometer stretch of open-coast beach near Duck, NC. An algorithm was developedto classify foredune state from 50-cm bare earth DEMs into four categories: scarped,recovering, healthy, and man-made. The algorithm was based on extraction ofmorphological features including the slope, volume, and curvature of the foreduneface. Preliminary results detailing the response of each foredune state to a 4-dayNorEaster (Hs = 4.8m at 16s in 8m of water) are presented, and suggest that manmadeand recovering dunes lost more volume and eroded more rapidly whencompared with scarped dunes. The increased erosion may have been due to acombination of slightly lower dune-toe elevations for the man-made dunes andunconsolidated sediment in the foredune.