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Evaluating environmental sensitivity to desertification: short presentation of the ESA methodology |
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Written by Agostino Ferrara
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The estimation of Environmental Sensibility to desertification at medium-large scale requires the setting up of elaboration and updating methodologies capable of handling considerable amounts of data in an integrated approach.
This would allow evaluating the different stages of environmental degradation as well as the existing interactions among the singular components of the territory.
The ‘ESA’ methodology on evaluating Environmental Sensibility of an Area is based on the integration of alphanumeric and cartography data with remote sensed images, using Geographic Information Systems. This approach does not only guarantees easy management of the data collected, their continuous updating and their rapid interpretation but it also offers the possibility to analyse the factors causing the phenomena in progress.
This methodology can be said to fall into the category of Key Indicator Based Systems. Using this approach, the Environmental Sensitivity to desertification of an area arises from the result of the interactions among elementary factors (indicators) that are differently linked to direct and indirect degradation or desertification phenomena. For example, these factors might correspond to inadequate land management quality compounded by more or less critical environmental factors (soil, climate, vegetation). Environmental Sensitivity to desertification is in fact strongly correlated to many environmental factors such as climate, soil, vegetation cover, morphology, etc., whose characteristics and degree of interaction strongly contribute to the evolution and characterisation of different levels or stages. The sensitivity is also strongly linked to socio-economic factors since man’s behaviour, and his social and economic actions, can greatly influence the evolution of various environmental characteristics. From a mathematical point of view the calculation of different degrees of environmental sensitivities is carried out in two phases. Firstly, four intermediate quality layers based on soil, climate, vegetation and management, are evaluated and then, secondly, the final Environmental Sensitivity to desertification of each Area is determined. More information can be found at:
Kosmas C., Ferrara A., Briasouli H., Imeson A. 1999. Methodology for mapping Environmentally Sensitive Areas (ESAs) to Desertification. In 'The Medalus project Mediterranean desertification and land use. Manual on key indicators of desertification and mapping environmentally sensitive areas to desertification. Edited by: C. Kosmas, M.Kirkby, N.Geeson. European Union 18882. pp:31-47 ISBN 92-828-6349-2. Manual can be downloaded from:
http://www.kcl.ac.uk/projects/desertlinks/downloads.htm
Ferrara A., 2005. Expert system for evaluating the Environmental Sensitivity Index (ESI) of a local area. In 'DIS4ME: Desertification Indicator System for Mediterranean Europe', Jane Brandt Ed. Web site: http://www.kcl.ac.uk/projects/desertlinks/ - ISSN: 1749-8996.
Ferrara A., Bellotti A., Faretta S., Mancino G., Baffari P., D'ottavio A., Trivigno V., 2005. Carta delle aree sensibili alla desertificazione della Regione Basilicata. FOREST@ (on line). vol. 2, pp. 60-67 ISSN: 1824-0119. Paper can be downloaded from: http://www.sisef.it/ |
