FORMA Raw Output NDVI (WRI/GFW/FORMA/raw_output_ndvi)

FORMA alerts are detected using a combination of two MODIS
products: NDVI (Normalized Difference Vegetation Index) and FIRMS
(Fires Information for Resource Management System). NDVI updates are
processed every 16 days, while fire updates are processed daily. Models
are developed individually for each ecogroup to relate the two inputs to
the area of clearing, using the Hansen annual tree cover loss data to train
the model. The minimum threshold to qualify as an alert is 25% of the pixel
cleared, though thresholds vary by ecogroup to minimize false positives.
Here is an example script
for a quick introduction to the FORMA datasets.

The images in this ImageCollection contain the raw FORMA data calculated after new
MODIS NDVI data becomes available, approximately every 16 days.

The image contains 4 bands. The ‘delta’, ‘near_term_delta’, and ‘clearing’ bands
all give a percentage of clearing (from 0 to 100) for different accumulation periods.
Accuracy gives a measure of confidence in these predictions
(0 = very little confidence, 100 is high confidence).

deltaPercentage of clearing in the last 96 days%
near_term_deltaPercentage of clearing in the last 32 days%
accuracyConfidence in predictions%
clearingPercentage of clearing in the last 365 days%


World Resources Institute / Global Forest Watch (producer, licensor)
Google Earth Engine (host)
STAC Version 0.6.2
Keywords FORMA, GFW, MODIS, WRI, daily, deforestation, forests, monitoring
License proprietary
Temporal Extent 12/31/2011, 4:00:00 PM - now
Type image_collection
GSD metersm
cube:dimensions {"x":{"type":"spatial","axis":"x","extent":[-120,180]},"y":{"type":"spatial","axis":"y","extent":[-50,40]},"temporal":{"type":"temporal","extent":["2012-01-01T00:00:00Z",null]},"bands":{"type":"bands","values":["delta","near_term_delta","accuracy","clearing"]}}