HIGH-RESOLUTION UAV MAPPING FOR SEAGRASS ALONG THE WEST COAST OF NORTH AMERICA

Unmanned Aerial Vehicles (UAV) mapping (often referred to as drone mapping) with its high spatial resolution, temporal flexibility and ability to repeat photogrammetry affords a significant advancement in other remote sensing approaches for coastal mapping, vegetation monitoring, and environmental management. In this project, we perform UAV mapping along the west coast of North America to measure seagrass meadow extent, patchiness, and dynamics in coordination with in situ sampling along the U.S. west coast. Seagrass habitats provide important services to coastal regions, including primary production, carbon storage, nutrient cycling, habitat for fisheries species, and erosion control. However, quantifying ecosystem-level impacts of disease to changes in the extent and density of seagrass habitat has not yet been attempted across spatial scales. High-resolution UAV mapping products were obtained for analyses of the seagrass morphology from different locations varying by latitude. This method quickly scans a relatively larger coverage for high-resolution imagery with less human risk. Local research partners and community stakeholders were trained flying UAV through an open-access training course and participatory research activities to collect high-quality data. Object-oriented analysis is utilized for spectral values, texture, canopy density, and other biological indexes. Ground-truthing across a range of points within each seagrass meadow is used to validate drone mapping imagery. The validation results show the UAV-based image analysis captured the seagrass's health level with a strong correlation with the in situ measurements, and provide reliable predicting results.