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Indicators in Practice

Mar 27, 2014

Global Forest Watch: Monitoring Earth’s Forests in Near Real-Time

The Global Forest Watch is an online forest monitoring and alert system that provides forest information in near real-time.

Case Study: Global Forest Watch

Scope: Global

First Release: 2014

Intended Audience: Government, Policymakers, Forest Managers, NGOs, Civil Society

Potential applications: Guiding and informing policymaking; disseminating information about forests to a global audience; motivating conversation about forests worldwide

Developers: World Resources Institute, Google, and other partners

Websites: http://www.globalforestwatch.org/

Description: Forest managers and policymakers now have a powerful new data-driven tool to monitor the state of the world’s forests. A consortium of more than 40 partners, including the World Resources Institute and Google, launched Global Forest Watch (GFW) on February 20, 2014. This online forest monitoring and alert system uses satellite-derived information, open data, and crowdsourcing to detect deforestation as it occurs on the ground in near real time. It provides insight on deforestation patterns in areas of dense forest that otherwise could not be effectively surveyed from the ground.

When visitors first access the GFW site, they are greeted by a global map that displays relevant forest statistics, including the number of hectares of forest cover loss in 2012, tree cover gain from 2000 to 2012, and the number of Forest Monitoring for Action (FORMA) alerts in the past month (see this post for a detailed description of FORMA). The FORMA alerts system, updated every 16 days, uses several parameters to detect potential disturbances in forest cover. A key component of the FORMA algorithm is the incorporation of Normalized Vegetation Index (NDVI) to indicate whether and where deforestation may be occurring across the world’s humid tropical forest biomes. NDVI, which is a product that uses several spectral bands from satellite data, represents a normalized difference of varying land surface reflectances in certain bands that allows for distinguishing between forest and landcover types. As the NDVI for forests is relatively high, a change in this index could indicate changes in forest cover. 


The FORMA system considers changes in NDVI (Normalized Difference Vegetation Index). This figure shows a single pixel’s NDVI history and analysis of its rate of change.

Readers are then given the option to click and explore the interactive map to view more detailed data on forest change, forest cover, forest use, and conservation on a global scale in real time. If a user wants to explore a country’s performance in detail, the GFW site provides can country profiles, which feature specific statistics and details for a specific country. Individual country profiles display an in-depth description of forests via FORMA alerts, tree cover data, real time analysis of forest change, and information on forest cover, forest use, and conservation.

One innovation the GFW introduces is a crowdsourcing component to engage citizens in forest monitoring and alerts. Stories are submitted by GFW users to report what is occurring in forests on the ground all over the world. If a person living in Indonesia detects illegal logging activity, for example, he or she can take a photo or record a video and upload a story or alert to the GFW website. This feature is similar to a growing number of initiatives to enlist “citizen scientists” in data collection. The Water Reporter application allows individuals to report litter or pollution in the Chesapeake Bay as a way of alerting local Watershed Managers of potential problems. However, a key challenge in any citizen science and crowdsourcing is attracting and incentivizing a user-base that will be motivated to contribute stories and information.

GFW is a tremendous step toward compiling large-scale datasets on forest information and making them readily and easily accessible to a range of audiences. Combined with consideration of conservation management and other indicators, such as the EPI’s biodiversity and habitat indicators, decision makers can begin to answer policy-relevant questions.  For example, linking the GFW results to the EPI’s indicators for biodiversity and habitat protection may provide a deeper understanding of whether forest protection policies are helping to protect key species that live in forests. 

GFW recognizes that deforestation continues to be a pressing issue throughout the world and is making significant strides to address this problem. By enabling viewers to access real-time deforestation data, GFW is both inspiring concern for and promoting understanding of this global problem.