An evaluation of the MEDALUS ESA index (environmental sensitivity to land degradation), from regional to plot scale

Abstract

An assessment of the sensitivity to land degradation have been carried out for the region of Extremadura, SW Spain, by means of the modelling approach developed in the European Commission funded MEDALUS project (Mediterranean Desertification and Land Use) which identifies such areas on the basis of an index (ESA index) that incorporates data on environmental quality (climate, vegetation, soil) as well as on anthropogenic factors (management). Two maps of environmental sensitivity to degradation with different legend resolution (4 and 8 classes of sensitivity) have been made. The results of the model were validated at different spatial scales, i.e.; regional and farm scales. True field data on degradation-related variables at the different spatial scales have been used in order to undertake the validation procedures. Selected farms covering different physiographical and socioeconomic characteristics were used to gather data at farm scale. Data gathered from the National Inventory of Soil Erosion was also used to validate the model at the regional scale.