Satellite data instrumental in combating desertification
With land degradation in dryland regions continuing to worsen, the UN Convention to Combat Desertification has agreed on scientist-recommended indicators for monitoring and assessing desertification that signatory countries must report on.
The landmark agreement was reached after two weeks of negotiations involving
hundreds of scientists and government ministers attending the Ninth Session of
the Conference of the Parties (COP 9) of the UN Convention to Combat
Desertification (UNCCD) in Buenos Aires, Argentina, from 21 September to 2
Desertification, land degradation and drought deprive people of food and
water and force millions to leave their homes. Desertification refers to the
creation of new deserts through the degradation of drylands, which cover 40% of
the worldâ€™s land surface. Land degradation, caused by over-cultivation,
over-grazing, deforestation and inefficient irrigation, affects roughly 20% of
Since dryland desertification can be remedied or even reversed by using
appropriate management techniques, scientists attending the first scientific
session of the COP, held from 22 to 24 September, stressed the importance of
developing science-based methods for monitoring the areas most at risk to
support land and water management decisions. Satellite technologies were
recognised as playing an important role in achieving this objective.
ESA has been working closely with the UNCCD secretariat for nearly 10 years,
developing and demonstrating innovative information services based on satellite
Earth observation (EO) technologies that allow land degradation processes to be
monitored over time.
Monitoring desertification, land degradation and droughts requires the
continuous evaluation of a complex set of parameters and indicators, some of
which can be retrieved with EO technologies and state-of-the-art geo-spatial
applications. For instance, the status of land cover â€“ one of the 11 indicators
defined by COP â€“ can be monitored from space.
In 2004, ESA launched a large pilot project called DesertWatch to develop a
set of land degradation indicators based principally on land surface parameters
retrieved from satellite observations. These indicators were developed with the
support of Italy, Portugal and Turkey â€“ three of the European countries mostly
affected by desertification. DesertWatch also helped these countries fulfil
their UNCCD reporting requirements by combining satellite data with weather and
in-situ data, numerical models and geo-information systems to create
standardised geo-information products.
ESA recently extended the project so that its methodology may be adapted and put
to wider use. To demonstrate its applicability, the methodology will be applied
to arid and semi-arid areas in Portugal, Brazil and Mozambique.
According to the UNCCD, soil moisture is another key parameter that should be
monitored, because it is an indicator of water scarcity and vegetation stress.
Soil moisture data can also be used for assessing drought risk.
The ESA-backed SHARE (Soil Moisture for Hydrometeorological Applications in the
Southern African Development Community Region) project has developed a
pre-operational soil moisture monitoring service with the long-term goal of
supplying free soil moisture information for all of Africa, at a resolution of 1
km, via the Internet. SHARE was developed under ESAâ€™s TIGER initiative, which
helps African countries to overcome water problems. DesertWatch and SHARE are
funded by the Data User Element (DUE) under ESAâ€™s EO Envelope Programme.
ESA hosted an exhibition booth and a side event at COP 9 entitled â€˜Earth
observations from space for the UNCCDâ€™, where the latest DesertWatch findings
and results were presented. The side event also served as a platform for
demonstrating the benefits of EO technology for the UNCCD Convention.
Speaking of DesertWatch, Dr Lucio do Rosario of the Portuguese delegation
said: "We recommend the UNCCD Contracting Parties to adopt these methodologies.
The benefits are multiple. They improve the monitoring and assessment of land
degradation, provide more efficient decision-making and facilitate the reporting
to the Convention on the indicators adopted by COP 9."
In a message to COP 9, UN Secretary General Banki-Moon said: "In addressing
climate change, the international community has tended, quite understandably, to
focus on cutting greenhouse-gas emissions. But tackling the issue in all its
complexity also requires to go beyond mitigation and take into account the
intrinsic linkages between desertification, land degradation and climate
ESA will continue to act on both fronts by helping the UNCCD community develop
monitoring and assessing tools and supporting the UN Framework Convention on
Climate Change (UNFCCC) community with long-term trend analyses of essential
The Tenth Conference of the Parties of the UNCCD will be hosted by the Republic
of Korea in October 2011.