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Using radiometric indicators for the study of arid ecosystems dynamics (region of Zougrata, South‐East of Tunisia) Volume 14, issue 4, OCTOBRE-NOVEMBRE-DÉCEMBRE 2003

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Author
Centre national de télédétection, BP 212, 1002 Tunis‐Belvèdère, Tunisie <razak_belghithyahoo.fr>

The characterisation of environment degradation is necessarily based on diachronic studies so that physical and biological changes affecting the components of the ecosystems can be detected. The degradation of these ecosystems, and conversely their restoration, are reflected on the ground by the modification of the area‘s components (vegetation and soil). This study which aims at characterising arid ecosystems dynamics, will be essentially based on ecological indicators highlighting the transformation at ground surface level. These indicators have shown that they were closely correlated with such radiometric indexes as the albedo, the surface temperature, the vegetation index and the colour index. As a result, a study methodology based on these radiometric indicators has been carried out with the following objectives: identification of degraded areas or areas undergoing a degradation process; apprehension of environmental changes according to climatic events; characterisation of the environment‘s response capacity (irreversibility problem).