MapBiomas Alerta is not a new alert system, but an effort to enhance the usability and effectiveness of alerts generated by existing systems. It is a collective construction based on consultation with users (MMA, IBAMA, SFB, ICMBio, MPF, etc.) and alert providers (INPE, Imazon, Geodatin, SOS Mata Atlântica, SOS Pantanal, University of Maryland, ISA, etc).

In general, existing systems detect alerts from large-scale analysis of medium-resolution satellite imagery (10 to 80 m resolution). These images are revisited weekly or fortnightly and allow for the identification of deforestation alerts, but without many options for analysis at the rural property level, given the spatial resolution and low frequency of image acquisition. 

In MapBiomas Alerta, deforestation alerts produced by the various monitoring initiatives are gathered, validated and refined using daily images with 3 m resolution. Each alert generated is accompanied by a high-resolution image of before and after the deforestation, similarly to the photo of the license plate of the vehicle in traffic infractions.

Yes. All alerts processed and published by MapBiomas Alerta go through a rigorous verification process. There are three steps: pre-validation, validation and audit.

  • Pre-Validation – includes two steps. The first is the automated elimination of all alerts that overlap with reforestation and agriculture areas present in MapBiomas' annual maps or that have already been detected in previous surveys. After this process, the remaining alerts go through visual analysis with the support of the high resolution monthly mosaics from Planet (images with 3 m resolution) and the analysts select the best pair of satellite images available to represent the moment before and after deforestation. At this point, the fraction of alerts that correspond to cases of false positives is discarded, with the corresponding record of the reason for rejection (forestry, agriculture, seasonality, etc.).
  • Validation – validation is performed at the time of sample collection for classification and refinement of the deforested polygon in high resolution images. The technician can rule out cases of false positives, with the corresponding record of the reason for rejection (forestry, agriculture, seasonality, etc.).
  • Audit – each refined alert goes through an audit process carried out by a technical supervisor from each biome. In this step, the eventual need to redo any adjustments is evaluated before the final publication of the refined alerts.

Daily images with 3 m resolution and daily acquisition are used, coming from the PlanetScope constellation with 200+ microsatellites.

Most deforestation alert polygons validated by MapBiomas are produced from training machine learning algorithms. These algorithms capture details of the geometry of deforestation polygons and changes in natural cover. During the refinement process, operations are performed to smooth the polygon and reduce the excess of vertices/corners as much as possible.

The beta version of the data was published as of OCT 2018. Since JAN 2019, all alerts from the sources used are evaluated and published.

Validated alerts are published weekly on the MapBiomas Alerta platform, usually every Tuesday.

Deforestation drivers are the likely economic activities or urban expansion that led to deforestation. In 2021, the validation process started to include in the analysis what the drivers are, such as agriculture, mining, mining, urban expansion and others. Also, the process for identifying deforestation from construction of wind and solar plants in Brazil is under development, mainly in the Northeast region.

The Alert Report is a document generated automatically on the MapBiomas Alerta platform gathers all the technical information about the alert, allowing direct and quick analysis of the location, probable dates of deforestation and relevant territorial/land overlapping, such as rural properties (limits of the Rural Environmental Registry - CAR) and protected areas, among others. This document serves to speed up and facilitate the analysis and implementation of law enforcement actions by the official federal and state agencies. When crossing a CAR property, it is possible to generate specific reports of the crossing with the alert and high resolution images of before and after deforestation, followed by additional information, such as:

  • overlapping of deforestation alert with protected areas (Conservation Units and Indigenous Territories), settlements, APP (Permanent Preservation Area), RL (Legal Reserve), springs, etc;
  • overlapping of the alert with areas with Authorization for the Suppression of Native Vegetation, Embargoes and Forest Management Plans;
  • history of land use and land cover in MapBiomas' maps for the last years;
  • alert descriptive memorandum (coordinates);
  • methodology;
  • data source.

Following the provisions of the Brazilian legislation, such as the General Data Protection Law, No. 13,709/2018, the data of the owners of properties registered in the CAR, such as name and CPF/CNPJ, are not available on the MapBiomas Alerta platform and are not available to the public at SICAR (National Rural Environmental Registry System).

This is a strict responsibility of the official government bodies of SISNAMA (National Environment System). The alert report contains information that can support the identification of signs of illegality in deforestation, for example: (i) it identifies whether there is authorization for the suppression of vegetation in force associated with the deforested area registered in the federal database (SINAFLOR - National Control System of Origin of Forest Products); (ii) identifies if there is deforestation in areas declared as APP or RL; (iii) identifies whether there is overlap with protected areas; (iv) identifies if there is overlap with embargoed areas.

All material is free and open, available on the website


Yes. The platform allows access to alerts and reports in several ways. You can download alerts as (i) Shapefile (.shp); (ii) consolidated data per year, with CAR information, as an EXCEL spreadsheet; (iii) the reports are available in PDF files; (iv) there is a plugin that accesses alerts in QGIS; (v) and a public API is available that allows access to alerts, images and attributes, as a service (open service for registered users. Register here:


Contact us via e-mail: suporte.alrta@mapbiomas.org

MapBiomas data is public, open and free by simply referring the source following the format below.

"MapBiomas Alert Project - Validation and Refinement System for Deforestation Alerts with High-Resolution Images: [LINK] accessed on [date]"