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A.H. Schumann and G.A. Schultz
deforestation and land use change. The management of forests, agricultural
lands and range-lands can play an important role in reducing current emissions
of carbon dioxide, methane and nitrous oxide and enhance carbon sinks.
Model projects show that the land cover of the earth could be changed significantly as a consequence of possible changes in temperature and water availability under double equivalent CO2 equilibrium conditions:
* a substantial fraction of the existing forested area of the world (a global
average of one-third) will undergo major changes in broad vegetation
types,
* the extent of desertification - land degradation in arid, semi-arid and dry
sub-humid areas- will increase
* the altitudinal distribution of vegetation will be changed.
Land cover can change because of human impact or natural forces. As the rates of
change in many places have accelerated a comprehensive view of land cover and
ecosystem change is needed. In the Land-Use and Land-Cover Change (LUCC)
project, a core project of the International Geosphere- Biosphere Programme
(IGBP) and the international Human Dimension of Global Environmental Change
Programme (HDP), regional case studies in different areas of the world have begun. The LUCC will aim for global coverage of land cover at 1 km spatial resolution. Satellite observation techniques have been developed that can determine
changes in land cover type, as well as spatial and seasonal changes in vegetation
(Defries and Townshend, 1994). Landsat imagery was used e.g. to measure deforestation in the Brazilian Amazon Basin. The area deforested increased from
78,000 to 230,000 km 2 from 1978 to 1988 (Skole & Tucker, 1993)
Land Cover Change Detection at Continental and National Scale. In many
countries activities were launched to estimate their land cover characteristics:
The U.S. Global Change Research Programme includes an initiative to classifY and
inventory North American land cover by analysing Landsat data from 1970 to the
present.
A U.S. Land Cover Characteristics Data Set 1990 prototype was set up at 1 km
resolution by the U.S. Geological Survey, which was developed from a combination of multi-temporal NOAA-A VHRR- data with a variety of earth science data
sets.
In Europe the CORINE programme (Co-ordination of Information on the Environment) was established in June 1985 by the European Community's Council of
Ministers. One of its objectives consists in the creation of a number of digital databases with the purpose to give information on the status and the changes of the
environment. The final product in the CORINE Land cover project is a digital land
cover database. The smallest mapping unit covers 25 hectares (which corresponds
to a resolution of 500m x 500m). The method adopted by most of the countries
that have conducted CORINE land cover projects is visual interpretation of satellite images (Landsat TM) at a scale of 1: 100.000 (Ahlcrona, 1995). In some
countries (e.g. in Sweden and the UK) the available Landsat data will be used to
estimate the land coverage with a finer resolution (e.g. by generalization into 5
A.H. Schumann and G.A. Schultz
deforestation and land use change. The management of forests, agricultural
lands and range-lands can play an important role in reducing current emissions
of carbon dioxide, methane and nitrous oxide and enhance carbon sinks.
Model projects show that the land cover of the earth could be changed significantly as a consequence of possible changes in temperature and water availability under double equivalent CO2 equilibrium conditions:
* a substantial fraction of the existing forested area of the world (a global
average of one-third) will undergo major changes in broad vegetation
types,
* the extent of desertification - land degradation in arid, semi-arid and dry
sub-humid areas- will increase
* the altitudinal distribution of vegetation will be changed.
Land cover can change because of human impact or natural forces. As the rates of
change in many places have accelerated a comprehensive view of land cover and
ecosystem change is needed. In the Land-Use and Land-Cover Change (LUCC)
project, a core project of the International Geosphere- Biosphere Programme
(IGBP) and the international Human Dimension of Global Environmental Change
Programme (HDP), regional case studies in different areas of the world have begun. The LUCC will aim for global coverage of land cover at 1 km spatial resolution. Satellite observation techniques have been developed that can determine
changes in land cover type, as well as spatial and seasonal changes in vegetation
(Defries and Townshend, 1994). Landsat imagery was used e.g. to measure deforestation in the Brazilian Amazon Basin. The area deforested increased from
78,000 to 230,000 km 2 from 1978 to 1988 (Skole & Tucker, 1993)
Land Cover Change Detection at Continental and National Scale. In many
countries activities were launched to estimate their land cover characteristics:
The U.S. Global Change Research Programme includes an initiative to classifY and
inventory North American land cover by analysing Landsat data from 1970 to the
present.
A U.S. Land Cover Characteristics Data Set 1990 prototype was set up at 1 km
resolution by the U.S. Geological Survey, which was developed from a combination of multi-temporal NOAA-A VHRR- data with a variety of earth science data
sets.
In Europe the CORINE programme (Co-ordination of Information on the Environment) was established in June 1985 by the European Community's Council of
Ministers. One of its objectives consists in the creation of a number of digital databases with the purpose to give information on the status and the changes of the
environment. The final product in the CORINE Land cover project is a digital land
cover database. The smallest mapping unit covers 25 hectares (which corresponds
to a resolution of 500m x 500m). The method adopted by most of the countries
that have conducted CORINE land cover projects is visual interpretation of satellite images (Landsat TM) at a scale of 1: 100.000 (Ahlcrona, 1995). In some
countries (e.g. in Sweden and the UK) the available Landsat data will be used to
estimate the land coverage with a finer resolution (e.g. by generalization into 5