Statewide Landcover And Trees Study (SLATS) Sentinel-2 - 2020 Woody Vegetation Age Since Disturbance - Queensland

The 2020 woody extent is attributed with an estimated age in years since the last significant disturbance. The method uses a sequential Conditional Random Fields classifier applied to 1988 - 2021 Landsat time series to predict woody cover over the 33-year period. A set of heuristic rules is used to detect and track regrowing woody vegetation in the time series of woody probabilities and record the approximate start and end dates of the most recent regrowth event. Regrowth detection is combined with the SLATS Landsat historic clearing data to provide a preliminary estimate of age since disturbance for each woody pixel in the 2020 woody extent. The 'last disturbance' may be due to a clearing event or other disturbance such as fire, flood, drought-related death etc. Note that not all recorded disturbances may result in complete loss of woody vegetation, so the estimated age since disturbance does not always represent the age of the ecosystem. The age since disturbance product is derived from multiple satellite image sources and derived products which represent different scales and resolutions: Landsat (30m), Sentinel-2 (10m) and Earth-i (1m).