Integrating a UAV-derived DEM in object-based image analysis increases habitat classification accuracy on coral reefs

Very shallow coral reefs (< 5 m deep) are naturally exposed to strong sea surface temperature variations, UV radiation and other stressors exacerbated by climate change, raising great concern over their future. As such, accurate and ecologically informative coral reef maps are fundamental for their management and conservation. Since traditional mapping and monitoring methods fall short in very shallow habitats, shallow reefs are increasingly mapped with Unmanned Aerial Vehicles (UAVs). UAV-imagery is commonly processed with Structure-from-Motion (SfM) to create orthomosaics and Digital Elevation Models (DEMs) spanning several hundred metres. Techniques to convert these SfM products to ecologically relevant habitat maps are still relatively underdeveloped. Here we demonstrate that incorporating geomorphometric variables (the DEM and its derivatives) in addition to spectral information (the orthomosaic) can greatly enhance the accuracy of automatic habitat classification. Therefore, we..., This dataset contains the Supplementary Data to:
 
Nieuwenhuis, B.O.; Marchese, F.; Casartelli, M.; Sabino, A.; van der Meij, S.E.T.; Benzoni, F. 
Integrating a UAV-Derived DEM in Object-Based Image Analysis Increases Habitat Classification Accuracy on Coral Reefs.
Remote Sensing. 2022, 14, 5017
 
There are 4 datasets stored here.

Dataset 1. UAV orthomosaics and DEMs

File folder with the UAV orthomosaics and DEMs as .tiff files.
Orthomosaics and DEMs were constructed by processing DJI Phantom 4 RTK images with the Structure-from-Motion Software Pix4D.
The file folder also contains a README.txt file with further explanation.

Dataset 2. Snorkel transect orthomosaics

File folder with the orthomosaics of the snorkel transects as .tiff files.
Orthomosaics were created from GoPro Hero 9 imagery processed with the Structure-from-Motion Software Agisoft Metashape.
The file folder also contains a README.txt file with further explanation.

Dataset 3. Habitat classifications

File folder wit..., GIS software is necessary to use and view the data. We advise the use of either ArcGis or QGIS (open-source).