New NASA satellite-generated land cover maps are providing scientists with a detailed picture of the distribution of Earth's ecosystems and land use. These new maps, based on a global digital database of land cover types that is updated every 16 days, will help scientists better understand the Earth's climate and carbon budget, through closer monitoring of water and land resources, including forested and agricultural areas.
These land-coverland cover maps were developed at Boston University in Boston, MA, using data from the Moderate-resolution Imaging -Spectroradiometer (MODIS) instrument aboard on NASA's Terra satellite. The prototype MODIS maps were created with data acquired between July and December 2000, but future maps will utilize one year of data.
Advances in remote sensing technology allow MODIS to collect higher-quality data than previous sensors, yielding the most detailed land cover classification maps to date. They are also more current because the information content of MODIS data allowed scientists to exploit more efficient automated methods for categorizing land cover than was previously possible, reducing the time to generate maps from months or years to about one week.
Each MODIS land cover map contains 17 different land cover types, differentiating among eleven natural vegetation types such as deciduous and evergreen forests, savannas, grasslands, permanent wetlands and shrublands. Agricultural land use, as well as several categories of land surfaces with little or no plant cover — such as bare ground, urban areas and permanent snow and ice — are also depicted in the maps.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 22.214.171.124.0