Global bare ground data are per pixel estimates of circa 2010 percent minimum (peak of growing season)
bare ground cover derived from cloud-free annual growing season composite Landsat 7 ETM+ data.
A regression tree model estimating per pixel percent bare ground was applied to annual composites
from 2000 to 2012 inclusive (Hansen and others, 2013). Data gaps and noise from individual years
were replaced using multi-year median values. First, a median from annual bare ground values from 2009-2011
was used to estimate 2010 bare ground. For pixels still lacking an estimate, the median calculation was
expanded to include bare ground values from 2008-2011, then from 2008-2012. Any remaining gaps were
filled with bare ground values derived from a regression tree model using all growing season Landsat ETM+
data as inputs. The resulting layer represents estimated minimum bare ground per pixel, 1-100% for the year
2010 in integer values (1-100).
Bare ground percentage per output grid cell is encoded as integer values (1-100).
Files are unsigned 8-bit data with spatial resolution of 1 arc-second per pixel
(approximately 30 meters per pixel at the equator). Data coverage is from 80° north to 60° south.
It is divided into tiles of 10 x 10 degrees.
Tiles over ocean area are included for completeness.
- Potapov, P., Turubanova, S., Tyukavina, A., Krylov, A., McCarty, J., Radeloff, V., and Hansen, M., 2015,
Eastern Europe's forest cover dynamics from 1985 to 2012 quantified from the full Landsat archive:
Remote Sensing of Environment, v. 159, p. 28-43, at
Hansen, M.C., Egorov, A., Potapov, P.V., Stehman, S.V., Tyukavina, A., Turubanova, S.A.,
Roy, D.P., Goetz, S.J., Loveland, T.R., Ju, J., Kommareddy, A., Kovalskyy, V., Forsyth, C.,
and Bents, T., 2014, Monitoring conterminous United States (CONUS) land cover change with
Web-Enabled Landsat Data (WELD): Remote Sensing of Environment, v. 140, p. 466-484, at ://000329766200038.
Hansen, M.C., DeFries, R.S., Townshend, J.R.G., Sohlberg, R., Dimiceli, C., and Carroll,
M., 2002, Towards an operational MODIS continuous field of percent tree cover algorithm:
examples using AVHRR and MODIS data: Remote Sensing of Environment, v. 83,
no. 1—2, p. 303—319, at
Hansen, M.C., Potapov, P.V., Moore, R., Hancher, M., Turubanova, S.A., Tyukavina, A., Thau, D., Stehman, S.V., Goetz, S.J.,
Loveland, T.R., Kommareddy, A., Egorov, A., Chini, L., Justice, C.O., and Townshend, J.R.G., 2013, High-Resolution Global Maps
of 21st-Century Forest Cover Change: Science, v. 342, no. 6160,
p. 850-853, at
University of Maryland, Department of Geographical Sciences and USGS; use is free to all if acknowledgement is made.
[ https://landcover.usgs.gov/glc/BareGroundDescriptionAndDownloads.php ]