NOTE from WRI: WRI decided to stop updating FORMA alerts. The goal was
to simplify the Global Forest Watch
user experience and reduce redundancy.
We found that Terra-i and
GLAD were more frequently used.
Moreover, using GLAD as a standard, found that Terra-i outperformed
FORMA globally.
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.
This image contains the thresholds at which, when crossed, a FORMA alert is
produced. The values are equal to max(25,40%*RegionalMax), where RegionalMax
is the historical maximum clearing for a pixel in this ecogroup.
Bands
Pixel Size 250 meters
Bands
Name
Units
Min
Max
Pixel Size
Description
delta_bound
%
25
40
meters
The thresholds at which, when crossed, a FORMA alert is produced
Terms of Use
Terms of Use
The FORMA datasets are available without restriction
on use or distribution. WRI does request that the
user give proper attribution and identify WRI and GFW, where applicable,
as the source of the data.
NOTE from WRI: WRI decided to stop updating FORMA alerts. The goal was to simplify the Global Forest Watch user experience and reduce redundancy. We found that Terra-i and GLAD were more frequently used. Moreover, using GLAD as a standard, found that Terra-i outperformed FORMA globally. FORMA alerts are detected …
[null,null,[],[[["\u003cp\u003eThe FORMA dataset provides forest alert thresholds, derived from MODIS NDVI and FIRMS data, indicating potential forest clearing.\u003c/p\u003e\n"],["\u003cp\u003eWRI, the dataset provider, has discontinued FORMA alert updates in favor of Terra-i and GLAD due to their performance and user preference.\u003c/p\u003e\n"],["\u003cp\u003eThresholds, representing the percentage of pixel cleared, vary by ecogroup to minimize false positives and trigger alerts when exceeded.\u003c/p\u003e\n"],["\u003cp\u003eThe dataset covers the period from 2012-01-01 to 2016-01-01 and has a spatial resolution of 250 meters.\u003c/p\u003e\n"],["\u003cp\u003eFORMA data is freely available for use and distribution with proper attribution to WRI and GFW.\u003c/p\u003e\n"]]],[],null,["# FORMA Alert Thresholds\n\nDataset Availability\n: 2012-01-01T00:00:00Z--2016-01-01T00:00:00Z\n\nDataset Provider\n:\n\n\n [World Resources Institute / Global Forest Watch](https://www.globalforestwatch.org/)\n\nTags\n:\n[daily](/earth-engine/datasets/tags/daily) [deforestation](/earth-engine/datasets/tags/deforestation) [fire](/earth-engine/datasets/tags/fire) [forest](/earth-engine/datasets/tags/forest) [forma](/earth-engine/datasets/tags/forma) [gfw](/earth-engine/datasets/tags/gfw) [modis](/earth-engine/datasets/tags/modis) [monitoring](/earth-engine/datasets/tags/monitoring) [wri](/earth-engine/datasets/tags/wri) \n\n#### Description\n\n**NOTE from WRI** : WRI decided to stop updating FORMA alerts. The goal was\nto simplify the [Global Forest Watch](https://www.globalforestwatch.org)\nuser experience and reduce redundancy.\nWe found that [Terra-i](http://www.terra-i.org/terra-i.html) and\n[GLAD](https://glad-forest-alert.appspot.com/) were more frequently used.\nMoreover, using GLAD as a standard, found that Terra-i outperformed\nFORMA globally.\n\nFORMA alerts are detected using a combination of two MODIS\nproducts: NDVI (Normalized Difference Vegetation Index) and FIRMS\n(Fires Information for Resource Management System). NDVI updates are\nprocessed every 16 days, while fire updates are processed daily. Models\nare developed individually for each ecogroup to relate the two inputs to\nthe area of clearing, using the Hansen annual tree cover loss data to train\nthe model. The minimum threshold to qualify as an alert is 25% of the pixel\ncleared, though thresholds vary by ecogroup to minimize false positives.\nHere is an [example script](https://code.earthengine.google.com/f29b1e4360f3fc36847bd789ceeb20f6)\nfor a quick introduction to the FORMA datasets.\n\nThis image contains the thresholds at which, when crossed, a FORMA alert is\nproduced. The values are equal to max(25,40%\\*RegionalMax), where RegionalMax\nis the historical maximum clearing for a pixel in this ecogroup.\n\n### Bands\n\n\n**Pixel Size**\n\n250 meters\n\n**Bands**\n\n| Name | Units | Min | Max | Pixel Size | Description |\n|---------------|-------|-----|-----|------------|------------------------------------------------------------------|\n| `delta_bound` | % | 25 | 40 | meters | The thresholds at which, when crossed, a FORMA alert is produced |\n\n### Terms of Use\n\n**Terms of Use**\n\nThe FORMA datasets are available without restriction\non use or distribution. WRI does request that the\nuser give proper attribution and identify WRI and GFW, where applicable,\nas the source of the data.\n\n### Explore with Earth Engine\n\n| **Important:** Earth Engine is a platform for petabyte-scale scientific analysis and visualization of geospatial datasets, both for public benefit and for business and government users. Earth Engine is free to use for research, education, and nonprofit use. To get started, please [register for Earth Engine access.](https://console.cloud.google.com/earth-engine)\n\n### Code Editor (JavaScript)\n\n```javascript\nvar dataset = ee.Image('WRI/GFW/FORMA/thresholds');\nvar thresholds = dataset.select('delta_bound');\nvar visParams = {\n min: 0,\n max: 50,\n};\nMap.setCenter(26, -8, 3);\nMap.addLayer(thresholds, visParams, 'Thresholds for FORMA alerts');\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/WRI/WRI_GFW_FORMA_thresholds) \n[FORMA Alert Thresholds](/earth-engine/datasets/catalog/WRI_GFW_FORMA_thresholds) \nNOTE from WRI: WRI decided to stop updating FORMA alerts. The goal was to simplify the Global Forest Watch user experience and reduce redundancy. We found that Terra-i and GLAD were more frequently used. Moreover, using GLAD as a standard, found that Terra-i outperformed FORMA globally. FORMA alerts are detected ... \nWRI/GFW/FORMA/thresholds, daily,deforestation,fire,forest,forma,gfw,modis,monitoring,wri \n2012-01-01T00:00:00Z/2016-01-01T00:00:00Z \n-50 -120 40 180 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [](https://doi.org/https://www.globalforestwatch.org/)\n- [](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/WRI_GFW_FORMA_thresholds)"]]
