An Application of Lidar to Examine Erosion in the Southern Monterey Bay During the 1997-98 El Nino

Light Detection and Ranging (LIDAR) was used in a Geographic Information Systems (GIS) to quantify coastal changes to beaches and dunes in the Southern% Monterey Bay region and to qualitatively assess the erosional impact of large storms on coastal dune areas. LIDAR provides a rapid and accurate survey technique to measure topographic elevation. A LIDAR survey was performed in October 1997 and then a second survey in April 1998 to measure the erosion occurring during the 1997-1998 El Nino winter storm. Maximum dune erosion occurred in the vicinity of Fort Ord (13 m) and Marina (15 m) along with significant dune recession in Monterey and Sand City. Beach erosion was prevalent from Moss Landing to Monterey showing the seasonal beach loss. There was a large spatial van ability all along the shoreline with many numerous erosional "hot spots". From the profile data the calculated volume loss from Monterey to Moss Landing (Æ22 km) was 88O,8OO m(3) which was calculated by multiplying the dune top recession between the two survey by the height of the dune from the toe to the dune top. From the cut fill calculation within ArcView total volume loss was calculated to be 2,47O,OOO m(3) which included both dune and beach erosion. LIDAR data provide a high-quality representation of the episodic erosion process in Southern Monterey Bay and also offers useful environmental information to the warfighter in terms of detailed beach or landing zone characterizations.Naval Postgraduate School Monterey CA is the author of 'An Application of Lidar to Examine Erosion in the Southern Monterey Bay During the 1997-98 El Nino' with ISBN 9781423549727 and ISBN 1423549724.