GlobeLand30 refers to the land cover of the earth
between latitude 80N to 80S. Presently, our website has provided the browsing
and downloading services for GlobeLand30-2010 (GlobeLand30-2010) in baseline
year of 2010. The brief information of this data product is as follows.
1．Images and Auxiliary Data
The images utilized for GlobeLand30 classification are multispectral images
with 30 meters, including the TM5 and ETM + of America Land Resources Satellite
(Landsat) and the multispectral images of China Environmental Disaster
Alleviation Satellite (HJ-1). Besides multispectral images, plenty of Auxiliary
data are also used in the process of data production such as sample collection
and classification, etc. They mainly contains: the existing land cover data
(global and regional), MODIS NDVI, global geographic information, global DEM,
thematic data (global mangrove forest, wetland and glacier, etc.) and online
resources (Google Earth, Bing Map, OpenStreetMap and Map World) and so on.
2. Classification Scheme
The classification system includes 10 land cover types, namely cultivated
land, forest, grassland, shrubland, wetland，water bodies, tundra, artificial
surfaces, bareland, permanent snow and ice. Please classification scheme is as
1) Cultivated Land. Lands used for agriculture, horticulture and gardens,
including paddy fields, irrigated and dry farmland, vegetation and fruit
2) Forest. Lands covered with trees, with vegetation cover over 30%,
including deciduous and coniferous forests, and sparse woodland with cover 10 -
3) Grassland. Lands covered by natural grass with cover over 10%, etc.
4) Shrubland. Lands covered with shrubs with cover over 30%, including
deciduous and evergreen shrubs, and desert steppe with cover over 10%, etc.
5) Water bodies. Water bodies in the land area, including river, lake,
reservoir, fish pond, etc.
6) Wetland. Lands covered with wetland plants and water bodies, including
inland marsh, lake marsh, river floodplain wetland, forest/shrub wetland, peat
bogs, mangrove and salt marsh, etc.
7) Tundra. Lands covered by lichen, moss, hardy perennial herb and shrubs in
the polar regions, including shrub tundra, herbaceous tundra, wet tundra and
barren tundra, etc.
8) Artificial surfaces. Lands modified by human activities, including all
kinds of habitation, industrial and mining area, transportation facilities, and
interior urban green zones and water bodies, etc.
9) Bareland. Lands with vegetation cover lower than 10%, including desert,
sandy fields, Gobi, bare rocks, saline and alkaline lands, etc.
10) Permanent snow and ice. Lands covered by permanent snow, glacier and
3. Data Composition and Format
GlobeLand30 data adopts raster data format for storage, with the
non-destructive GeoTIFF compression format and the 256 indexed color pattern of
the 8 Bit. The data consist of 5 parts, namely classification result file,
coordinate information file, map setting file of classification image, metadata
file and illustrative file.
4. Data Organization
GlobeLand30 data adopts WGS84 coordinate system, UTM projection, 6-degree
zoning and the reference ellipsoid is WGS 84 ellipsoid. According to different
latitude situations, 2 methods are adopted to organize the data tiles. Within
the area of 60°N and 60°S, the data tile is implemented according to the size of
5° (latitude) * 6° (longitude); within the area of 60° to 80° degrees north and
south of the equator, the data tile is implemented according to the size of 5°
(latitude) * 12° (longitude) and the projection is conducted according to the
central meridian of 6°zone with an odd number.
There are 853 data tiles in the whole world in total and the covering
situation of specific picture is shown as Figure 1.
Figure 1 Data tile of
5. Accuracy Assessment
Nine types and over 150,000 test samples are evaluated in terms of accuracy
assessment. The overall accuracy of GlobeLand30-2010 reaches 80.33%. The Kappa
indicator is 0.75.
6. Contact Information
If you need a further understanding of the detailed information of the
product, please refer to Product Manual (http://glc30.tianditu.com). If you have
any question and suggestion, please contact Doctor Chen Lijun and his contact
details are as follows:
Lijun Chen Ph.D
National Geomatics Center of China (NGCC)
28 Lianhuachi West Road, Beijing, 100830, China