ABSTRACT
Desertification is currently defined as land degradation in arid, semi-arid and dry sub-humid regions, resulting from various factors, including climatic variation and human activities. Typical examples of degradation include landforms produced by accelerated wind and water erosion, salinization and vegetation degradation. In Africa, drought and its impacts are considered major components of desertification. With time, the meaning of desertification has gone beyond the simple bio-physical connotation of land degradation, and has encompassed more the attributes of sustainable land management and livelihoods, while the monitoring and assessment focus more on an integrated understanding of the bio-physical and socio-economic variables. With this shift in the meaning, the combating of desertification has started focusing more on programs involving people’s participation than on top-down, science-led approaches. The changes have come in the background of a long-continued scientific research on various aspects of desertification, as well as healthy scientific debate on its concept, methodologies and role in societal good, including the role of UNCCD, the international body that was created to co-ordinate and monitor the task of desertification control globally. With changes in concept and methodologies, the mapping and monitoring of degradation and its impacts are also getting revised, while new technologies for integrating bio-physical and socio-economic variables are being increasingly used through remote sensing and GIS applications. This review discusses the causes and effects of desertification in the light of recent developments, with examples from Thar Desert and elsewhere.
