Land cover is the physical material at the land surface of Earth. Land covers include flora, concrete, built structures, bare ground, and temporary water. Earth cover is the expression used by ecologist Frederick Edward Clements that has as its closest modern equivalent vegetation. The expression continues to be used by the United States Bureau of Land Management.
There are two primary methods for capturing information on land cover: field survey, and analysis of remotely sensed imagery. Land change models can be built from these types of data to assess changes in land cover over time.