area of barren land NLCD:31 An area of a planet's surface which is primarily composed of bedrock, desert pavement, scarp rock, talus, material exposed by slides, volcanic material, glacial debris, sand, material exposed during strip mining, gravel, and other accumulations of earthen material in contact with an atmospheric column extending from the planetary boundary layer to the planet's exosphere with little to no physical obstruction. nlcd2011 envoPolar Barren Land (Rock/Sand/Clay) According to the NLCD 2011, areas of barren land generally have less than 15% cover of vegetation. A specific threshold is not asserted in this definition. terrestrial environmental zone