Introduction
Many international and national organizations have since long recognized that environmental and socio-economic indicators are playing an increasingly important role in supporting development policies for combating desertification. An indicator is a measurement that reflects the status of some social, economic or environmental system. Indicators can be used to track changes in complex systems and monitor progress towards pre-determined goals. Their role is to simplify the complex interrelations of the socio-economic and environmental reality and convey them in an unambiguous fashion. In this way indicators can be used to integrate socio-economic and biophysical factors. The necessity of elaborating indicators is one of the priorities identified by the United Nations Convention to Combat Desertification (UNCCD). The Convention regards indicators as the appropriate tool to provide operational support to a wide range of activities such as assessing and mapping the extent of desertification, as well as determining the causes, quantifying the impacts, justifying expenditure for mitigation measures and monitoring the efficiency of the measures undertaken. The identification, evaluation and the effective use of indicators requires a series of characteristics that have been proposed by various authors (Stein et al., 2001). In 2001 the DESERTLINKS project was set up to assist the National Action Plans of the Annex IV countries with their indicator needs and this resulted in the state-of-the art DIS4ME indicator system that can be consulted on line by stakeholders.
It is clear the necessity for identifying a series of indicators of desertification based on scientific criteria in order to guarantee a close and real relationship between the indicator and the state or trend that it represents. One core question about indicators is their feasibility and usefulness. The most appropriate indicator is not the one that provides best information about the state and future trends for desertification but the indicator that takes into account the available information and knowledge under low cost. For the identification and evaluation of indicators a series of characteristics have been proposed by various authors (Riley, 2001; Stein et al., 2001). The selected indicators have to be: (a) objectively and scientifically measurable, (b) preferentially quantitative, (c) easy and cost-effective to be measured, (d) sensitive to environmental changes, (e) simple in concept and accessible to both specialists and land managers, and (f) able to support policy decisions.
Several descriptions and definitions of the term "indicator" have been given by various agencies. The European Environmental Agency (EEA) has considered that an indicator can be defined as a parameter or value derived from parameters, which provides information about a phenomenon (OECD, 1993; EEA, 1998). In this sense indicators should not be confused with raw data, from which they are derived. Indicators are quantified information which helps to explain how things are changing over time and space (EEA, 1998). Indicators generally simplify the reality in order to make complex phenomena quantifiable, so that information can be communicated (Department of Environment, UK, 1996; EEA, 1998). It should be added at this point that when a complex process has to be described (for example the process of soil erosion), a single indicator is generally not sufficient, thus, several indicators would be necessary, even if not many, but organized into a precise set. In particular, an environmental indicator is a parameter, which provides information about the situation or trends in the state of environment, in the human activities that affect or are affected by the environment, or about relationships among such variables (USA EPA, 1995; EEA, 1998). The objectives of this WB are to:
- Define a practical number of indicators based on a shortlist of indicators available from literature, previous and ongoing research programs.
- Analyse stakeholders perceptions of desertification: an institutional and stakeholder analysis will be performed (with WB1 and WB3) to characterize major stakeholder groups in different sectors and regions and socio-economic backgrounds, their interests, their power, the current formal and informal institutional settings.
- Document and develop a harmonized data base of indicators used or being used by different parties in the selected study areas by conducting field surveys on prevailing land use types affecting desertification in Mediterranean locales.
- Compare and link indicators and land management practices among the various studied hot spots
- Develop a methodology to simulate and evaluate the various land management practices and techniques in terms of land degradation and economic feasibility for combating desertification using the appropriate indicators.
