Observing and Understanding Land Degradation and Desertification in the Countries of the Mediterranean Basin
The amount and conditions of terrestrial vegetation is a sensitive indicator of the broader response of the terrestrial biosphere to environmental forcing. The latter comprises both climate variability and human disturbance. The issue of desertification cannot be addressed without a brief review of the definitions given in literature. Different definitions imply different land surface processes and data requirements. Definitions based on vegetation cover and its variability in response to climate variability lead to monitoring procedures feasible with easily accessible and up-to-date information. More complex definitions, based on detailed analysis of soil conditions and of land use, lead to significantly more severe data requirements. The contribution of earth observation to the understanding of desertification and land degradation depends on how these terms are understood in the community and society. Two extreme situations may eventually occur: 1) The terms land degradation and desertification are understood in their broadest sense. This extends the domain of the response to desertification and land degradation to all aspects of environment, with the Response System being society with its governance system. The aim becomes a sustainable equilibrium of society with its physical environment. 2) The terms land degradation and desertification acquire a much narrower meaning, possibly dropping the term desertification altogether. Attention is then restricted to the aspects of land degradation most relevant to specific situations, e. g. a region or a landscape. This leads to precise information requirements and possibly to identify specific remedial actions. Spectro-radiometric data collected from space can be used in several different ways to observe the response of terrestrial vegetation to environmental forcing. For the sake of convenience we may consider two categories: A) use of reflectance in the red and near-infrared spectral range to construct spectral indices, which provide a proxy measurement of leaf display; B) inverse modeling of spectro-directional radiometric data to retrieve biophysical variables. The presentation will provide examples of both categories.
drought desertification Mediterranean remote sensing
M. MENENTI
Institute of Mediterranean Agro-Forestry (ISAFoM), National Research Council (CNR), P. O. Box 101 80040 S. Sebastiano al Vesuvio (NA), Italy
国际会议
中国-欧盟荒漠化综合治理研讨会(The China-EU Workshop on Integrated Approach to Combat Desertification)
北京
英文
42-54
2003-10-15（万方平台首次上网日期，不代表论文的发表时间）