USE OF EARTH OBSERVATION SATELLITE DATA FOR LAND DEGRADATION MAPPING AND MONITORING IN MEDITERRANEAN ECOSYSTEMS - TOWARDS A SATELLITE-OBSERVATORY

The degradation of the permanent seminatural vegetation and the result ing acceleration of soil degradation and erosion processes constitute major elements of land degradation in the Mediterranean basin. Given t he European Commission's interest in mapping and controlling desertifi cation phenomena in the Mediterranean member states, the ''Environment al Mapping and Modelling Unit'' (EMAP) of the Joint Research Centre is investigating possibilities for using operational earth observation s atellites for mapping and repeated monitoring of vegetation and soil c haracteristics. In the context of previous experiments, approaches hav e been developed that can already be routinely applied to large region s. This paper discusses the problems of standardized retrieval of remo tely sensed primary parameters (such as reflectance), concepts relatin g to the thematic interpretation of reflectance data, and the definiti on of satellite-derived degradation indices. In addition, this paper p resents requirements for designing an operational satellite observator y for monitoring Mediterranean land degradation.