Mangroves provide a range of essential ecosystem services, from coastal protection, habitat provision and carbon sequestration. However mangroves are impacted by a wide range of natural and anthropogenic drivers leading to losses and gains in mangrove extent. Multi-decadal archives of satellite imagery provide a unique opportunity for tracking changes in mangrove extent over time at continental scales. The Digital Earth Australia (DEA) contains 3 decades of Landsat satellite surface reflectance which has been converted into fractional cover using algorithms developed by the Joint Remote Sensing Research Progam. The green cover fraction measures the percentage of each pixel that contains green vegetation. For vegetation with little or no understory such as mangroves, the 25th percentile of green cover fraction observed per year can be used to provide a consistent measure of canopy cover. The 25th percentile of the DEA fractional cover product for each calendar year between 1988 and 2017 was calculated and a mangrove extent mask, based on the Global Mangrove Watch polygon was applied. The result is a series of maps that show the mangrove canopy cover for each year. This talk describes the mangrove canopy cover product with examples of how canopy cover has responded to disturbance events such as severe tropical cyclones.
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