Hansen year-on-year tree-cover loss

hansen_yoy_loss · v2.1.0

Measures tree-cover-loss area within an asset analysis geometry for a defined year window using Hansen Global Forest Change data processed in Google Earth Engine.

Inputs

• Verified asset footprint polygon, or a centroid and configured analysis radius when no footprint is available.
• Start year and exclusive end year.
• Hansen Global Forest Change loss and lossyear bands from the registered dataset version.

Calculation

The method masks loss pixels whose encoded loss year falls inside the requested window. Google Earth Engine performs a server-side sum over the analysis geometry at 30-metre scale. The pixel count is converted to hectares using 0.09 hectares per 30 × 30 metre pixel.

Outputs

• hectares of tree-cover loss, rounded to two decimal places;
• assessment window and spatial basis;
• registered dataset and model version;
• a signed visualization-tile reference for inspection;
• signed evidence manifest and methodology-pack reference.

Limitations

Tree-cover loss is not automatically equivalent to deforestation caused by the asset. Attribution depends on spatial boundary quality, temporal operating history and nearby activity. A centroid buffer is a screening approximation; a verified footprint or attributed polygon is preferred. The source's publication cadence limits recency.

Primary source

University of Maryland Hansen Global Forest Change, distributed through Google Earth Engine. Miombo records the precise asset identifier and dataset version used by each assessment.