Mapping sensitivity to land degradation in Extremadura. SW Spain

Abstract

An assessment of sensitivity to land degradation has been carried out in the Extremadura region, SW Spain, by means of a modelling approach developed by the European Commission funded MEDALUS project (Mediterranean Desertification and Land Use) which identifies such areas on the basis of an index (Environmentally Sensitive Area index, ESA index) that incorporates data on environmental quality (climate, vegetation, soil) as well as anthropogenic factors (management). Two maps of environmental sensitivity (ES) to degradation with different legend resolution (four and eight classes of sensitivity) have been made and tested by comparing classes of the legends with an extensive number (2690) of true field data gathered from plots distributed all over the study region. Independent variables of validation consisted of nine degradation-related types of data and the method tested the performance of the whole model and the statistical separability among classes of sensitivity, as well as the capability of the variables in delimiting the classes. Results showed a good performance of the whole model to both, the map of four and eighth classes of sensitivity. Separation among classes of sensitivity showed a slightly different behaviour of both maps, identifying transitional classes in the map of eight classes where classification could be improved in terms of the ranges of ESA index values assigned to the different classes.

Identifying areas susceptible to desertification in the Brazilian northeast

“…The MEDALUS methodology is based on the environmentally sensitive area index (ESAI; Parvari et al, 2011;Salvati et al, 2011;Izzo et al, 2013;Jafari and Bakhshandehmeh, 2013). In order to identify areas potentially affected by land degradation, the method analyzes four main variables: climate, soil, vegetation and land management (Kosmas et al, 1999(Kosmas et al, , 2006Lavado Contador et al, 2009). It has been validated on regional and local scales (Basso et al, 2000;Brandt et al, 2003;Salvati and Bajocco, 2011) and was applied to quantify the impact of mitigation policies against desertification (Basso et al, 2012).…”

Estimating the sensitivity to desertification of Italian forests

“…The Mediterranean area is recognized as an especially vulnerable region to land degradation and global climate change and that this issue cannot be underestimated by the scientific and policy making community (Lavado Contador et al 2009, Salvati et al 2013d.…”

“…The ESA method has been extensively validated at several sites in southern Europe (Kosmas et al 1999, Basso et al 2010, Salvati et al 2013b, 2013c, in middle and far East (Sepher et al 2007, Honardoust et al 2011) and in Africa, also for climate change analysing ); a regional assessment (Lavado Contador et al 2009), based on heterogeneous geographical datasets with different reliability, indicates the ESAI as a proxy for land degradation processes and identifies correlations with a number of indicators of soil degradation. Ferrara et al (2012) evaluated the stability of the ESAI using statistical analysis and the sensitivity to changes in the composing indicators.…”

“…To our knowledge, the selected data sources are the most reliable and updated for regional and country level assessments of the ESAI in Mediterranean countries (see also Salvati 2012 for a discussion on supply-demand of statistical data in desertification matters). Indicators of land sensitivity were obtained by applying a standard weighting system (ranging from 1 to 2 -see (Kosmas et al 1999, Basso et al 2000, 2012, Lavado Contador et al 2009). The ESAI was estimated in each spatial unit and year as the geometric mean of the variables described above.…”

Land Sensitivity Analysis of Degradation using MEDALUS model: Case Study of Deliblato Sands, Serbia

“…Over large areas of the world soils are exposed to the loss of biological production and resilience caused by both natural and anthropogenic factors (Contador et al 2009). In dry areas, land degradation coupled with extreme bio-physical and socio-economic phenomena may turn into an irreversible process of environmental degradation -desertifi cation (Montanarella 2007).…”