Benthic Habitat Mapping in Barnegat Bay with Topographic-Bathymetric Lidar Waveform Features

TitleBenthic Habitat Mapping in Barnegat Bay with Topographic-Bathymetric Lidar Waveform Features
Publication TypeConference Abstract
Year2014
AuthorsParrish, Christopher E., and Dijkstra, Jenn
Conference NameEuropean LiDAR Mapping Forum
Conference Dates8-10 December
Conference LocationAmsterdam, North Holland, The Netherlands

Barnegat Bay, a large, shallow estuary located along the New Jersey coast, was heavily impacted by Hurricane Sandy in 2012. Scientists and coastal managers are interested in assessing the impacts of the storm on benthic habitats, including eelgrass (Zostera marina) habitat, which is often used as an indicator of the overall health of the estuary. In this study, we evaluate the ability to map benthic habitats and conduct Sandy-related change analysis using data from two new topographic-bathymetric lidar systems, with fundamentally different design characteristics than conventional bathymetric lidar systems. After straightforward preprocessing, features related to return waveform shape are used in an object-based image analysis (OBIA) software environment to extract five classes: 1) deeper water (relative to the laser extinction depth), 2) sand, 3) dense eelgrass, 4) sparse eelgrass, and 5) mixed macroalgae and sand. The accuracies of the resulting habitat maps are then assessed using reference data acquired by a field survey team. Results obtained to date are very promising and indicate the potential of new topographic-bathymetric lidar waveform data for a range of coastal science and management applications.