An Evaluation of Vessel Based LiDAR Surveying as a Tool for Monitoring Short Term Change in Coastal Wetlands

Coastal wetlands are rapidly changing due to the impacts of climate change, sea-level rise, and coastal development. In light of these rapid changes, accurate and timely information on the morphology and dynamics of coastal wetlands is essential to their proper management. Currently many management agencies use aerial LiDAR surveys to detect geomorphic change over large areas, allowing rapid assessment of rates of erosion and accretion. Aerial based surveys however typically can only detect vertical changes as small as 10 cm and achieve horizontal resolutions of 1 meter or more. As an alternative, vessel based LiDAR, a topgraphic LiDAR system mounted on a moving platform, allows for geomorphic change detection at much higher resolutions (< 1 cm horizontal and vertical for LiDAR), making it possible to monitor dynamic systems over a much shorter time period and at much finer scales. The efficacy of vessel based LIDAR surveying to detect short term changes was tested in Elkhorn Slough in Monterey Bay, California using vessel based LiDAR surveys completed in 2009 and 2010. These vessel-based LiDAR data were merged with multibeam sonar surveys which were collected at the same time, to create complete digital elevation models of Elkhorn Slough. These data will be compared with 1998 and 2004 aerial LiDAR surveys in a geographic information system for data quality, resolution, and efficacy as methods for erosion detection with results ready for presentation at the 2010 American Geophysical Union conference held in San Francisco, CA.