LCMAP CONUS Reference Data
The LCMAP (Land Change Monitoring, Assessment, and Projection) conterminous United States (CONUS) Reference Data Product is an independent collection of land cover class labels at ~27,000 30-meter by 30-meter plots across CONUS. The land use, land cover, and change process information for each plot are available for annual timesteps.
A critical component of the LCMAP initiative is the collection of an independent reference dataset of land cover class labels used for the evaluation and validation of the LCMAP Science Products and for estimating land cover class composition for CONUS. The LCMAP Reference Data Products consist of 2 sample strategies involving 30-meter by 30-meter plots across CONUS. The initial Reference Data Product contains a dataset of 25,000 randomly distributed plots while the Intensification Reference Data Product includes an additional 2,000 plots collected via stratified random sampling. The land use, land cover, and change process information for each plot was collected annually using the TimeSync tool, a web-based interface for manually interpreting and recording land cover from the Landsat dataset (Cohen et al., 2010). Manual interpretation of Landsat data was supplemented with fine resolution imagery and other ancillary data. Various quality assurance and quality control (QA/QC) processes were developed and implemented to ensure that the LCMAP Reference Data Products are of consistent quality (Pengra et al., 2020). The initial collection effort involved 25,000 plots for the years 1984–2016, with later efforts adding data for the additional 2,000 stratified random plots as well as additional years of data. All 27,000 plots have been updated to include data from 2017-2021. For more information on the reference data collection process, see Pengra et al., 2020 and the documentation listed below.
Product Contents
The LCMAP Reference Data Product is packaged in a zipped file containing reference data for the initial 25,000 plots in three formats:
- Tabular (.xlsx) collection of the LCMAP reference dataset annual attributes (1984 –2021) for each of the 25,000 plots.
- Vector-format shapefile (.shp) for the LCMAP reference dataset showing individual plot (polygon) location outlines for each of the 25,000 plots. Annual attributes are not included.
Attribute data for the additional 2,000 stratified random plots:
- Tabular (.xlsx) collection of the LCMAP reference dataset annual attributes (1984-2021) for each of the 2,000 plots.
- Vector-format shapefile (.shp) for the LCMAP reference dataset showing individual plot (polygon) location outlines for each of the 2,000 plots. Annual attributes are not included.
- Tagged image format (.tif) map of stratum class (determined by land cover change type of the pixel). The additional 2,000 plots were selected via random distribution within each stratum.
Data Access
The Reference Data Product is accessible through the USGS Science Data Catalog.
Documentation
LCMAP Reference Data Product Guide
LCMAP Reference Data Product 1984 – 2021 Digital Object Identifier (DOI): doi:10.5066/P933Z1TK
Citation Information
There are no restrictions on the use of the LCMAP Reference Data Products. It is not a requirement of data use, but the following citation may be used in publication or presentation materials to acknowledge the USGS as a data source and to credit the original research.
LCMAP Reference Data products courtesy of the U.S. Geological Survey Earth Resources Observation and Science Center.
Pengra, B.W., Stehman, S.V., Horton, J.A., Auch, R.F., Kambly, S., Knuppe, M., Sorenson, D., Robison, C., and Taylor, J.L., 2023, LCMAP CONUS Reference Data Product 1984-2021 land cover, land use and change process attributes: U.S. Geological Survey data release, https://doi.org/10.5066/P933Z1TK.
Pengra, B.W., Stehman, S.V., Horton, J.A., Dockter, D.J., Schroeder, T.A., Yang, Z., Hernandez, A.J., Healey, S.P., Cohen, W.B., Finco, M.V., Gay, C., and Houseman, I.W., 2020, LCMAP Reference Data Product 1984-2018 land cover, land use and change process attributes (ver. 1.2, November 2021): U.S. Geological Survey data release, https://doi.org/10.5066/P9ZWOXJ7.
Pengra, B.W., Stehman, S.V., Horton, J.A., Auch, R.F., Dockter, D.J., Kambly, S., Taylor, J.L., 2021, LCMAP CONUS Intensification Reference Data Product 1984-2019 land cover, land use and change process attributes: U.S. Geological Survey data release, https://doi.org/10.5066/P9QA5Q25.
Reprints or citations of papers or oral presentations based on USGS data are welcome to help the USGS stay informed of how data are being used.
References
Cohen, W. B., Yang, Z., & Kennedy, R. (2010). Detecting trends in forest disturbance and recovery using yearly Landsat time series: 2. TimeSync — Tools for calibration and validation. Remote Sensing of Environment, 114(12), 2911-2924. https://doi.org/10.1016/j.rse.2010.07.010
Pengra, B. W., Stehman, S. V., Horton, J. A., Dockter, D. J., Schroeder, T. A., Yang, Z., Cohen, W. B., Healey, S. P., Loveland, T. R. (2020). Quality control and assessment of interpreter consistency of annual land cover reference data in an operational national monitoring program. Remote Sensing of Environment, 238, 111261. https://doi.org/10.1016/j.rse.2019.111261
Stehman, S. V., Olofsson, P., Woodcock, C. E., Herold, M., & Friedl, M. A. (2012). A global land-cover validation data set, II: augmenting a stratified sampling design to estimate accuracy by region and land-cover class. International Journal of Remote Sensing, 33(22), 6975-6993. https://doi.org/10.1080/01431161.2012.695092