Desertification is the degradation of land in arid, semi-arid, and dry sub-humid areas. It is caused primarily by human activities and climatic variations. Desertification occurs because dryland ecosystems are extremely vulnerable to over-exploitation and inappropriate land use. Poverty, political instability, deforestation, overgrazing, and bad irrigation practices can all undermine the land's productivity.

Combating desertification is essential to ensuring the long-term productivity of inhabited drylands. Unfortunately, past efforts have too often failed, and around the world the problem of land degradation continues to worsen. Recognizing the need for a fresh approach, 179 governments have joined as of March 2002, the United Nations Convention to Combat Desertification. This Convention aims to promote effective action through innovative local programmes and supportive international partnerships.

Countries affected by desertification are implementing the Convention by carrying out national and regional action programmes. Criteria for preparing these programmes are detailed in five regional implementation annexes: Africa, Asia, Latin America and the Caribbean, the Central and Eastern Europe and the Northern Mediterranean. The DesertWatch project focused on the latter.

The DesertWatch project aimed at developing a user-tailored, standardised, commonly accepted and operational information system based on EO technology to support national and regional authorities of Annex IV countries in reporting commonly to the UNCCD and assessing and monitoring desertification and its trends over time. From a methodological viewpoint the project exploited the most consolidated scientific results derived from the research and application projects funded by the EC, ESA and the national programmes (e.g., TESEO-Desertification, DISMED, LADAMER, DESERTLINKS, MEDALUS). The project aimed at bringing the gap between the extensive research work carried out in the last years and the operational needs of the user community.