Background
This project was developed as a way to visualize changes in timber harvests (both volumes and locations) over time in Washington State.
Historical timber harvest volume data is available from the Washington State Department of Natural Resources (DNR), but harvest locations are not. As a proxy for timber harvest locations ownership data from two recent projects was used to create a visual representation of where and how intensely timber was harvested from 1965 to 2013.
Our Work
We developed a method to spatially display timber harvests in Washington State over time by land owner type and using this method, created a series of maps for the Director of the School of Environmental and Forest Sciences.
Starting in 1965 and working forward to 2013, DNR data was normalized into a standard format, and classified by county, year, and owner class.
Spatial locations for the harvests on public lands were developed from the Public Land Inventory database developed for the Washington State Recreation and Conservation Office (RCO). Private Ownership data came from a derivative of the 2012 Washington State Parcel Database developed for the DNR as part of the Washington Biomass Assessment. Land ownership polygons were combined with county polygons, creating polygons for each owner class in each county.
Land ownership records are not available back to 1965, so it is not possible to change owner class boundaries over time for all landowners and times. Current boundaries were used, and it was assumed (and known to be inaccurate) that these boundaries were the same back to 1965. It was possible to change in land ownership boundaries for private lands transferred to State ownership for the years 2003 to 2013.
Using a ‘Dot Density’ symbology, the combined owner class/county polygons were filled with dots based on the timber harvest volume for each owner class in each county in each year. Fewer dots represent less volume, more dots represent more volume.
Deliverables
Project Summary
Timber Harvest Volumes by Year, County and Owner Class 1965-2013.csv
Metadata
Interactive Data Explorer
http://nrsig.org/apps/wahistoricharvest/
Spreadsheets
SummarizedVolumesByYearAndOwnerClass.xlsx
10YearAveragesByCountyAndOwnerClass.xlsx
10YearAveragesByCounty.xlsx
10YearAveragesByOwnerClass.xlsx
