Remote Sensing and Geomatics Strategies for Desertification and Land Degradation Monitoring and Assessment

• During the past 10 years, the European Commission has funded numerous dedicated research projects in the field of land degradation and desertification which focussed on data collection in specific field sites, detailed methodological studies, assessment and monitoring experiments, and the development of specific modelling concepts. Although substantial scientific progress has been achieved and some projects succeeded to link a considerable number of field sites and case studies across the Mediterranean basin, the scientific community has, apart from few initiatives not been able to provide unifying concepts for assessing land degradation processes on at least scale as required by political decision makers. Major fields of remote sensing and geomatics related research are in the development and application of methodologies to assess and monitor desertification and land degradation processes, especially in the European Mediterranean. While initial efforts were mostly confined to the evaluation of potential spatial indicators of degradation and how these could be inferred from spatial data sources, current approaches focus on methodological improvements, their multi-temporal application, and the development of remote sensing based environmental process models. In this context, an increasing integration with different disciplines is of utmost importance to proceed from purely descriptive approaches towards the definition of alternative management strategies to support the prevention or mitigation of land degradation. In this context, the GeoRange project focused on the implementation of integrated assessment concepts for multifunctional Mediterranean rangelands. These are based on retrospective data sets, where long time series of medium resolution satellite images have been set up and quantitatively analysed with respect to proportional vegetation cover as the target indicator of rangeland condition. Trend analyses were then calculated to characterize the development of vegetation cover with time, and interpretation frameworks were defined to interpret the resulting statistical parameters with regard to different problem regimes, such as wild fires, grazing and others. While the integration of remote sensing derived information into ecological process models has triggered widespread applications using medium and high resolution imagery, increasing emphasis is attributed to the synoptic, integrated assessment of larger spatial units, and the provision of dedicated information products for administrations and policy-makers. In the frame of the GMES initiative of the European Commission, the Ladamer project aims at the small-scale assessment of the degradation status of large areas, and the identification of degradation ‘hot spots’. In order to meet these prerequisites, the remote sensing interface, which so far has been based on limited data series obtained from earth observation satellites must now be extended to accommodate small scale multi-year observations from global monitoring satellites; this approach also forms the backbone of the remote sensing component of the recently launched Integrated European Project DeSurvey. An alternative approach is followed by the DesertWatch project which has recently been launched by the European Space Agency (ESA). This program is primarily triggered to derive land use changes in desertification-affected European countries based on the analysis of Earth observation satellite data from three distinct time steps (1984-1994-2004). Its complementarity to the Ladamer Project suggest that both projects should establish linkages to optimise their impact.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Naturgeografi (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Physical Geography (hsv//eng)

Keyword

remote sensing

desertification

DeSurvey

land degradation monitoring

Publication and Content Type

kon (subject category)

ref (subject category)