Action Against Desertification

Massive new survey of land restoration in Africa's drylands

Action Against Desertification continues groundbreaking efforts charting the Great Green Wall


Rome – Action Against Desertification is expanding its groundbreaking monitoring work on dryland restoration in Africa’s Great Green Wall area with a survey of evidence-based biophysical data of land restoration, covering over two hundred million hectares of land around the Sahara.

Until recently, drylands and their uses were not well understood or researched. As a consequence, restoration efforts lacked the focus to bring back health and productivity to degraded land. However, things have changed significantly since FAO took on a lead role, deploying an innovative tool called Collect Earth that uses very-high-resolution satellite images provided by Google Earth Engine and Bing Maps. 

An expert meeting in Rome in January 2015 opened the way to the first global assessment of trees, forests and land use in drylands, an analysis of over 200,000 sample plots in a collaborative effort involving regional and international partners, national governments, non-governmental organizations and academic institutions.

Its results, showing that forests in drylands are much more extensive than previously assumed, were published in Science Magazine in May 2017. The assessment also enabled to map the restoration needs and opportunities for Africa’s Great Green Wall area for the first time, where 166 million hectares offer opportunities for restoration.

Now, Action Against Desertification is moving its innovative monitoring efforts to the next level. In June 2018, some 25 experts from different Great Green Wall countries and partner organizations converged in Rome to start piecing together evidenced-based biophysical restoration data.

Using a new customization of FAO’s Collect Earth, specially tailored to the monitoring of agro-sylvo-pastoral ecosystems in the areas concerned, the experts are collecting data on land conditions and changes in an area of more than two million hectares around the Sahara – nearly 20% of the surface of the twelve countries involved. 

With a sampling density of four times higher than during the previous exercise, expectations are that the bio-physical information, combined with climatic data, will greatly improve understanding of the drivers behind desertification, as well as the effectiveness of restoration interventions and to assess mitigation potential for the next 20-30 years.

The survey is expected to be completed in early 2019.