COASTAL ENGINEERING APPLICATIONS OF HIGH-RESOLUTION LIDAR BATHYMETRY

In 1994, the US Army Corps of Engineers completed development of the S canning Hydrographic Operational Airborne Lidar Survey (SHOALS) system , a state-of-the-art hydrographic survey instrument. Using lidar (Ligh t Detection And Ranging) technology and operating from a Bell 212 heli copter, SHOALS remotely collects accurate, high-resolution bathymetry at a rate of 8 km(2)/h. A nominal depth-and-position measurement spaci ng of 4 m yields high-density bottom coverage of coastal projects, pro ducing soundings from the above-water beach, or coastal structure, to depths of 40 m. Since becoming fully operational SHOALS surveyed over 2000 km(2) along the Atlantic Ocean, Pacific Ocean, Gulf of Mexico, Gr eat Lakes, and Caribbean Sea. Survey projects varied from tidal inlets and navigation channels to beach nourishment and monitoring. These pr ojects quantify current coastal structure condition, navigation channe l alignments, and morphologic changes over time. In addition to monito ring coastal projects, sediment transport can be estimated with accura te, high-resolution bathymetry. Bathymetry can be translated into sedi ment transport through a combination of the sediment continuity equati on, a surf zone energetics-based longshore transport formula, and bath ymetric data. This paper presents the SHOALS system describing both li dar technology and the survey system. Several SHOALS data sets are pre sented to show today's benefits of high-resolution lidar bathymetry to the coastal engineering community. Finally, ongoing research using th ese unique data sets is presented to show the future benefits of lidar bathymetry to the coastal field. (C) 1998 Elsevier Science B.V. All r ights reserved.