- GIS Methodology Development
- Geodatabase Construction
- Historical Tract Digitization
- Aerial Imagery Analysis
Coastal Resources Inc. (CRI) provided a range of geospatial services to locate and digitize a back log of historical harvest tracts into a company-specific, multi-state geodatabase.
Enviva, one of the world’s largest wood pellet companies, produces over 3 million metric tons of pellets annually across seven production plants, located in the southeastern United States. In recognition of the need to maintain thriving forests for their product, Enviva developed the Track & Trace (T&T) program, to track every ton of wood purchased back to its origin in the forest or at a sawmill. This allows Enviva to ensure that their sourcing adheres to their sustainability policy and aligns with their values as a company.
While Enviva achieved full T&T coverage in June 2016, gaps within the harvest data from the early days of the tracking program in 2015 remained. The quality and accuracy of the location data has improved since the launch of T&T; however, some of the information in the historic T&T dataset was unclear, leading to a backlog of harvest tracts that had not been digitized into a geodatabase. In early 2018, CRI was contracted to develop a workable methodology, using GIS, for identifying historic harvest areas sourced by Enviva, and to create a comprehensive historical tract geodatabase.
This geodatabase was formatted to include all tract data that is collected during harvest, and split into state-level feature classes, so that tracts within each state would be drawn in the appropriate geospatial projection system. This resulted in the development of 5 feature classes, 1 for each state where Enviva harvests, had occurred: Alabama, Florida, Georgia, North Carolina, and Virginia. Using Enviva’s coordinate dataset, harvest tracts were located and digitized into the appropriate feature class. A variety of existing aerial imagery layers were compared to determine forest removal extent, in conjunction with state-specific or county-specific parcel data to confirm landowner information. Due to variable coordinate quality, a ranking system was developed to describe how, and with what ease, tracts were ultimately located. A tract with a rank of 1, for example, had correct coordinates that landed directly on an obvious harvest with a matching landowner, where lower ranks were assigned for incorrect landowners, incorrect coordinates, or out-of-date imagery. For tracts that were missing or had incorrect coordinates, landowner information or descriptive location information (when available) was used to determine landowner parcels, and imagery was then used to confirm if a tract had been cleared. All tracts received descriptive notes on how they were located. Any tracts that could not be located were given spreadsheet tracking notes on the search effort made, so they could be revisited should Enviva wish to search for them.
A complete written methodology of the steps used to located and digitize the historical tracts was developed, including all data sources utilized in the tract search. Using this methodology, Enviva’s own staff can continue the digitization efforts as harvests continue and new data is received, as well as revisit any sites that could potentially be located as new data becomes available. A total of 1,220 tracts were reviewed, with 974 being successfully located and digitized. Of the remaining 246 sites, 26 were determined to be duplicate data entries, leaving 220 that could not be located with the location data provided. As final deliverables, CRI provided Enviva with a complete, fully attributed geodatabase with all located tracts, a spreadsheet of the tracts remaining to be found and those that could not be located, and the methodology document for their use in locating additional tracts in the future.
Following this successful geodatabase development effort, Enviva gave CRI an additional contract to digitize up to 2,195 additional sites from more recent harvests dating from 2017 to mid-2018 that had yet to be digitized from forester provided data. Tract location data for the additional sites was more complete, and included tracts in South Carolina, in addition to sites from the states covered in the original contract. Using forester sketch maps when available and more accurate forester-collected GPS data points, CRI was able to successfully digitize 2,141 tracts out of 2,195 total tracts, with 41 identified duplicates, and 13 unable to be located.