A common device for the monitoring of desertification in circum-Saharan Africa: achievements and retrospective overview

That the ROSELT/OSS programme is complex, ambitious and demanding is probably a reflection of the absolute importance of its tasks. It was established to respond to the need to monitor and assess ongoing degradation, with reliable indicators. They must be relevant and allow both generalisation and extrapolation, drawing on data from the tight interdependence between environment and sustainable development. The only true response possible was to establish facilities for long-term environmental surveillance.