Reef's geomorphology, its benthic habitats and specific
coral types.
Roelfsema and his team began with the topographic map.
They processed 129 Sentinel-2 satellite images into
seamless mosaics, and water depth, slope and wave
values were derived using a previously established
algorithm. They also incorporated any field survey data
they could find on the GBR.
To create a larger reference dataset, they applied
the same eCognition rules from the initial set of 237
geomorphic reef maps to an additional 63 GBR reefs,
producing geomorphic and benthic habitat maps for 300
reefs total.
Given the enormity of the GBR and the terabytes of data
to be analyzed, the team switched the classification and
mapping process to Google Earth Engine (GEE). Using the
Dense healthy coral just under the water surface close to the reef
crest at Heron, Southern Great Barrier Reef. Photo: C.Roelfsema
The mv Kalinda sits anchored at Ellison Reef in the Central Great Barrier Reef. Two smaller boats launch from here to drop divers and snorkelers
off to collect georeferenced photo quadrate data along and on top of the reef to calibrate and validate habitat maps. Photo: K. Joyce
