Land desertification is recognized as a major threat to soil resources in arid, semi-arid Mediterranean areas. The use of widely applicable methodologies can facilitate the identification of land desertification risk spatio-temporal trends, which allows transnational comparison and support the development of soil management practices and policies, protecting the valuable soil resources. The aim of this study is to improve and use the Environmentally Sensitive Areas (ESAs) MEDALUS methodology, in order to provide a qualitative assessment for desertification risk trends in Greece, within the last 45 years. The Management, Vegetation, Soil and Climate quality indices (MQI, VQI, SQI, CQI) and the sub-sequent Environmental Sensitive Areas Index (ESAI) have been modeled for three periods in the entire Greek territory. The four quality indices are divided in two main categories, based on data availability and inherent characteristics, such as the pace of change during the studied period. Particular emphasis is given to the assessment of MQI, by integrating criteria which derived from national policies and the elaboration of national statistical data. The results show about 9% increase of the areas characterized as Critical to land desertification risk, while Fragile, Potentially affected and Non-affected areas decrease by 3.7%, 3.6%, 2.5% respectively. The applied approach for MQI can reveal areas where particular attention to management practices is required and improves the performance of the overall desertification risk index.
Spatial Coverage: Greece
Time Reference: 1970-1985, 1985-2000, 2000-2015
Format: Shape files
Projection: Greek Geodetic System EGSA'87
Input data: A number of datasets such as topographic (slope) and five soil characteristics (drainage, soil texture, soil depth, parent material,rock fragments) were used for Soil Quality Index (SQI). The assessment of the Climate Quality Index (CQI) required climate (rainfall, temperature) and topographic (slope aspect) data. The Vegetation Quality Index (VQI) assessment was based on the evaluation of vegetation resistance to drought (drought resistance), the flammability of plant species (fire risk), the protection that plants provide against soil erosion (erosion protection), and the percentage of the study unit covered by the dominant vegetation type (plant cover). Management Quality Index (MQI) requests the data on Land Use Intensity (LUI) Index and Policy Implementation (PI) Index.
Release Date: 26/11/2018
As a case study, Greece has been selected since it is one EU-Member State enlisted in the UNCCD Regional Implementation Annex IV.
Three main periods of consideration can be distinguished for the purpose of our study: (i) 1970–1985, (ii) 1985–2000, and (iii) 2000–2015.
Based on the MEDALUS methodology, the assessment involves two stages. In the first step, four independent indices for soil quality (SQI), climate quality (CQI), vegetation quality (VQI) and land management quality (MQI), are calculated. In the second step, these indices are integrated into the composite ESA index. The geometrical average of the four indices reveals the risk of an area to be affected by desertification.
The output of the geometrical average of the four indices (namely the ESA index) is classified in eight classes: ‘Non-affected’ (N), ‘Potentially affected’ (P), three ‘Fragile’ classes (F1–F3) and three ‘Critical’ classes (C1–C3). The three Fragile classes characterize areas where even a small external pressure to soil system could cause imbalances, favoring land desertification processes. The three sub-classes (F1, F2, F3) indicate the susceptibility to this risk, with F1 indicating the lower susceptibility and F3 the higher. The same logic applies for the Critical classes, however in this case the areas are already degraded and suggest potential threat to neighboring areas.
The methodology and the results of this study are explained in the recent published paper .