MANGROVE_25_2.0.2

Brief description

This mangrove canopy cover product provides valuable information about the extent and canopy density of mangroves for each year between 1987 and 2018 for the entire Australian coastline.

The canopy cover classes are 20-50% (pale green), 50-80% (mid green), 80-100% (dark green). The product consists of a sequence (one per year) of 25-metre resolution maps that are generated by analysing the Landsat fractional cover developed by the Joint Remote Sensing Research Program (https://doi.org/10.6084/m9.figshare.94250.v1) and the Global Mangrove Watch layers developed by the Japanese Aerospace Exploration Agency (https://doi.org/10.1071/MF13177).

This product can be cited as Lymburner, L., Bunting, P., Lucas, R., Scarth, P., Alam, I., Phillips, C., Ticehurst, C. and Held, A. (2018). Mapping the multi-decadal mangrove dynamics of the Australian coastline. See https://www.sciencedirect.com/science/article/pii/S0034425719301890.

Lineage

Maintenance and Update Frequency: asNeeded

Statement: The product development methodology is outlined in the following steps. - Calculate the green fractional cover (GVpc) from all available cloud-free Landsat pixels for each year of observation and compare these over an annual time series to identify areas where green cover persists throughout the year. - Establish a relationship between the 10th percentile of green fraction (GVpc10) observed within a year and Planimetric Canopy Cover percentage (PCC%) derived from <1 m spatial resolution canopy masks derived from LIght Detection And Ranging (LiDAR) with this representing a unit that relates directly to forest cover. - Constrain the PCC% estimates to areas known to contain mangroves, with reference to the Japanese Aerospace Exploration Agency’s (JAXA) Kyoto and Carbon (K&C) Initiative Global Mangrove Watch (GMW) thematic layers for 1996, 2007-10 and 2015/16 with additional areas identified using tasseled cap wetness and State and Territory mangrove-mapping products. - Apply PCC% thresholds to map mangrove forest extent (based on a pre-determined 20 PCC% threshold) and differentiate structural categories, namely woodland (20-50 %), open forest (50-80 %), and closed forest (>80%). - Quantify the change in the extent of mangrove forest and canopy cover types over the period 1987 to 2018 at a national scale and establish relevance at regional (e.g. State/Territory) and local levels.