monitoring, but many of the classification work still rely on the
manually investigation.
In general, these classification systems always focus on special
research objectives in different regions and scales. Land
use/land cover datasets based on those systems are not easy to
transform, exchange and integration without uniform
classification framework.
2. EXTENSIBLE LAND USE/LAND COVER
CLASSIFICATION FRAMEWORK
2.1 ISO 19115 Geographic information metadata extension
model
Sometimes, there are common problems in different research
domains. The difficulties faced to land use/land cover
classification systems are similar with the problem of metadata
standards when they are used in data integration and sharing.
Because there are lots of metadata standards in the same or
different research fields, datasets based on one special metadata
standard can’t be exchanged or integrated with another dataset
based on another metadata standard. Faced to this problem, ISO
TC211 designed extension model and drew up an International
Metadata Standard for Geographic Information, i.e., ISO 19115.
This extension idea is helpful for the design of extensible land
use/land cover classification model.
Figure 1. Extending Framework of Geosciences Metadata
Extension model of ISO 19115 defines the hierarchy extensible
structure of geographic information which includes 3 tiers, i.e.,
core metadata, schema metadata and application profile
metadata (Figure 1). Core metadata includes the elements
needed for all, which are used to build the metadata catalogue,
such as the elements for dataset name, abstract, keywords, and
so on. Schema metadata is also called corpora or full metadata.
It is used for description of the metadata content in detail, such
as datasets ’ production information, data quality information,
and so on. Application profile metadata is extended based on
the core metadata and schema metadata driven by the
application requirements. In practice, application profile
metadata must include all the core metadata elements and some
of the schema metadata elements. This can ensure different
discipline metadata be exchanged and inter-operated each other
under the ISO 19115 standard.
2.2 Extensible land use/land cover classification framework
structure
Referencing to the ISO 19115 metadata extension model, land
use/land cover extension framework is designed (figure 2). The
framework includes three tiers, i.e., core classes, corpora classes
and application profile classes.
Figure 2. Extension Framework of Land use/cover classification
2.2.1 Core classes
Similar with the ISO 19115 core metadata, core classes are the
smallest collection for land use and land cover classification
based on remotely sensed data. Core classes are selected and
extracted from the level I classes of the main land use/land
cover classification systems in the word, such as urban and
built-up land, agriculture land, water, and so on.
2.2.2 Corpora classes
Corpora classes include all the classification type information
used in the world. Currently, it was composed of 6 kinds of land
use/land cover classification systems mainly used in China.
They are listed as follows.
1. USGS Land use/land cover classification system,
which includes 9 Level I types and 37 Level II types.
Level I types are listed as follows: Urban or Built-up
Land, Agricultural Land, Rangeland, Forest Land,
Water, Wetland, Barren Land, Tundra, Perennial
Snow or Ice.
2. FAO LCCS, which includes 2 kinds of initial types.
3. IGBP Land cover classification system, which
includes 17 Level I types. They are Evergreen
Needleleaf Forest, Evergreen Broadleaf Forest,
Deciduous Needleleaf Forest, Deciduous Broadleaf
Forest, Mixed Forest, Closed Shrublands, Open
Shrublands, Woody Savannas, Savannas, Grasslands,
Permanent Wetlands, Croplands, Urban and Built-Up,
Cropland/Natural Vegetation Mosaic, Snow and Ice,
Barren or Sparsely Vegetated, Water Bodies.
4. UMd land cover classification system, which includes
14 Level I types. They are Water, Evergreen
Needleleaf Forest, Evergreen Broadleaf Forest,
Deciduous Needleleaf Forest, Deciduous Broadleaf
Forest, Mixed Forest, Woodland, Wooded Grassland,
Closed Shrubland, Open Shrubland, Grassland,
Cropland, Bare Ground, Urban and Built.
5. Chinese Academy of Sciences land resources
classification system, which includes 6 Level I types.
They are Agriculture land, Forestry land, Grassland,
Water, Urban or Built-up Land, Virgin land. It has 25
Level II types in detail.
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