Remote Sensing of Land-Cover and Land-Use Dynamics

Land is changing at a rate never achieved before. This evolution needs to be documented by robust and repeatable figures. Earth Observation tools play a key-role in the production of regular estimates of the landscape changes. In this chapter, we discuss the utility of Remote Sensing data for producing information on land-cover and on land-cover / land-use changes. Basic guidelines in terms of legend, data acquisition, classification techniques and validation are explained. For illustrating global land-cover projects, the recent Global Land Cover 2000 project is described. Two main land-cover change phenomena are exposed in the text: tropical deforestation (at pan-tropical level and for the Congo Basin) and agricultural expansion in Africa (continental level and for Senegal). In 1990 there were some 1,150 million hectares of tropical rain forest with an annual deforestation area for the humid tropics estimated at 5.8 million hectares. A further 2.3 million hectares per year of forest are detected as degraded – e.g. due to fragmentation, logging and / or fires. In the sub humid and dry tropics, annual deforestation for the tropical moist deciduous and the tropical dry forests comes respectively to 2.2 and 0.7 million hectares. Southeast Asia is the region where forests are under the highest pressure with an annual change rate of 0.8-0.9%, while changes are moderated in South America (0.4-0.5%) and in the Congo Basin (0.2-0.3%). For the agricultural expansion, the reported study shows that Africa has lost 16% of its forests and 5% of its woodlands and grasslands over the 1975 to 2000 period, equating to over 50,000 km2 per year of natural vegetation. The majority of this has been converted to agricultural lands. West Africa has seen the most change.

MAYAUX Philippe;  EVA Hugh;  BRINK Andreas;  ACHARD Frederic;  BELWARD Alan; 

2008-01-17

Springer

JRC37605

978-1-4020-6357-2,   

http://www.springer.com/west/home/geosciences?SGWID=4-10006-22-173741420-detailsPage=ppmmedia,    toc,    https://publications.jrc.ec.europa.eu/repository/handle/JRC37605,