Summary of methods: 

1. Creating the areas of interest for Forest Eye: 

All data for Forest Eye was downloaded from the BC Government Data Catalogue. This included shape files for old growth forests mapped as ‘Map 1: Priority Deferral Area’ or as ‘Map 8: Old Growth Forest’ by the Old Growth Technical Advisory Panel (TAP) as well as Forest Tenure Cutblock Polygons mapped by the B.C. government (hereafter referred to as the logging permit map)

The logging permit map was filtered to remove retired permit areas and permit areas where the planned harvest date was before 2020 or after 2030. Recreational permits were omitted, as well as area-based tenures such as Tree Farm Licenses (TFLs) and community forests that were fully mapped (e.g. were not just the maps of active harvest permits). Additionally, BCTS areas indicated with ‘Timber Sales Manager’ as the client name were also removed because these areas were previously part of confirmed deferrals (although this has changed – see “Why isn’t BCTS included”). 

Intersects of both old growth maps were made with the logging permit map in GIS to identify areas of overlap. The resulting overlap was merged to maintain all original metadata on all maps and the areas of the resulting overlap were calculated in hectares geodetically. 

NOTE: the logging permit map is not a complete picture of old growth logging in B.C. Private forestry is absent from the map, as are some cutblocks done in area-based licenses. In addition, new permits are being approved all the time, while the maps underpinning the tool are only updated twice per year, or more frequently if major changes occur. 

2. Utilizing remote-sensing

The resulting map of the overlap between old growth and logging permits is uploaded to Upstream Tech’s Lens software, which utilizes the normalized difference vegetation index (NDVI) to detect unseasonal changes in vegetation cover. NDVI uses remote sensing from satellite data to quantify the health and density of vegetation using red and near-infrared bands. When a drop in vegetation is detected in an area of overlap, an alert is generated. 

3. Screening and confirming alerts

Not all alerts are logging, or even true forest clearances, and so they must each be screened to verify what triggered the alert. This is done using Planet Labs monthly satellite images in Lens and daily and monthly images in Planet Explorer. Alerts are dismissed if there is no visible vegetation drop on satellite images, if the vegetation drop is due to natural disturbance (e.g. fire), or if the vegetation drop occurred prior to January 2020. Indicators like roads and slash piles confirm the presence of logging and time lapse videos reveal the timing and progression of road-building and harvesting. Data collection is completed in Lens for all confirmed alerts, including the confirmed road-building and logging dates (to month and year), the total area harvested, the type and amount of old growth area lost (Map 1 (candidate deferrals) and/or Map 8 (other old growth), the biogeoclimatic (BEC) zone, the company holding the logging permit, the cutblock identification, the region/district/ and landscape unit, and the latitude and longitude of the area.

4. Database, website, and public notifications

An API calls all of the data collected and bespoke R-code written by SRG parses the data into columns in a database built in-house. The data is analysed and all images associated with the alert are catalogued for use in public notifications. The map and tracker on the website are updated automatically when the database is refreshed. Public notifications are batched to be sent out over social media at least once a week. 

Disclaimer: This database has been prepared using best practices and due diligence using information available at the date of publication. All information is subject to change. All data is obtained from public or government sources including but not limited to B.C. government maps and metadata on old growth forests, priority deferrals, and forest harvesting permits. If you represent a company that appears in this database that you believe is not accurately represented, supplemental information can be sent to