Saturday, March 2nd, 2019, 12:31pm
09/01/2018
The MapBiomas Project today released a revision of the annual maps of land cover and land use in Brazil for the period 2000-2016. Collection 2.3 updates the data from Collection 2 launched in April 2017.
The main aspects of this review include:
- Legend simplification - some legend classes, especially at the third level of detail, which had spectral similarities with other classes or were only identified in certain biomes were aggregated. The terms for native vegetation classes have also been adapted to improve understanding. The changes are aimed at making the maps more practical and straightforward to understand.
- Accuracy analysis - a complete accuracy analysis of the land cover and land use maps was carried out, covering all the years and legend class of their different levels. The overall accuracy of the 2.3 collection was 79.3% at legend level 1, with an allocation error of 9.5% and an area error of 11.2%. On the online platform it is now possible to consult the accuracy by class, year, biome and legend level.
- Consistency of the time series - the variations in cover and use classes gained more spatial consistency over the time series, reducing noise, especially in the data on class transitions between years, due to the adoption of automatic decision trees based on the Random Forest algorithm.
- Simplifying access to maps and data for analysis - several improvements have been implemented in the data visualization and access module, including: (i) comparative visualization of the classification and mosaic of images from two years across the entire territory; (ii) availability of coverage maps from all years in a single file for download by biome; and (iii) statistical data on coverage and transitions consolidated by municipality, state and biomes, available for download in an Excel spreadsheet. These improvements are the result of advances in the processing algorithms, in particular (i) the inclusion of a new approach to automatic classification which used the results of Collection 2 to train the Random Forest classification algorithm; and (ii) the inclusion of new temporal and spatial filter stages after the thematic map integration process. These advances are described in the ATBDs (algorithm base documents) also available on the platform
- Most of the improvements to this collection were inspired by the demands, criticisms and suggestions that came from the MapBiomas Scientific Committee meetings, the thematic workshops promoted by the project and, above all, the contributions of dozens of users of the platform who have used the data for countless applications.
To strengthen this link with users, it is now possible to create an access profile on the MapBiomas platform. From this profile you can create and save maps of the territories you are interested in and generate a URL to include these maps on your own web pages. This access profile will also allow users to keep up to date with MapBiomas news.
The MapBiomas team is now working on the preparation of Collection 3, which is due to be launched in 2018 with annual land cover and land use maps covering the period from 1985 to 2017.