With a quarter of the Earth’s land surface affected, the United Nations Convention to Combat Desertification regards desertification as a worldwide problem. Delegates from the 170-plus signatories to the Convention currently gathered in Nairobi have been briefed by ESA representatives and national partners on how satellites are being used to track desertification in Europe. The Seventh Session of the Conference of the Parties (COP 7) of the United Nations Convention to Combat Desertification (UNCCD) is currently ongoing in in Kenya’s capital.
The UNCCD was established in 1994, in the wake of the 1992 Earth Summit in Rio de Janeiro which recognised desertification as a major social and environmental problem. Desertification does not so much as refer to the spread of existing deserts as the creation of new ones, through the reduction of productivity of vulnerable dryland areas by soil deterioration and erosion as well as the long-term loss of natural vegetation. Such drylands cover 40% of the world’s land surface, and are the habitat and source of livelihood for more than one billion people.
ESA is backing a satellite-based information service called DesertWatch, working with national partners of four of the European countries most affected by desertification: the Greek, Italian, Portuguese and Turkish National Representatives to the UNCCD. Dryland desertification can be remedied or even reversed, provided information is available on what areas are most at risk. Satellite images can highlight relevant land use change along with increased surface reflectivity, temperature, dryness and dustiness. Infrared sensors can detect vegetation stress due to environmental shifts. This satellite data is being combined with in-situ information, processing tools, models and GIS to create standardised and comparable geo-information products that can also be used to satisfy UNCCD reporting requirements. DesertWatch products include national and sub-national risk maps plus severity/recovery maps, pressure indicators and state indicators. The intention is to create a means of authoritatively assessing and monitoring desertification and its trends over time.