Desertification has been steadily increasing not only due to human activities such as excessive husbandry over-cultivation of land, deforestation, the cutting of firewood and salinisation caused by indiscriminate irrigation, but also because of global climatic changes. Around one-third of the Earth's surface is threatened, and the subsistence of more than 100 million people is directly concerned.

The combination of aerial photos and satellite images allows one to monitor the long-term evolution of the vegetal coverage in an endangered region. However, the use of satellite images is even more important for warning systems which make possible long-term planning for the threatened zones. Thanks to the high frequency of their global images, sensors such as NOAA AVHRR, Meteosat and SPOT Vegetation permit one to follow closely changes in vegetal coverage and note in time any deviations from the normal pattern.

SATELLITE DATA

SPOT XS

SPOT VGT