Desertification indicators as diagnosis criteria for desertification risk assessment in Europe

Despite the seriousness of the environmental and socio-economic impacts of desertification, few efforts have been made to devise diagnostic and monitoring techniques for appraising the status and trend of desertification. Indicators are integrated and synthetic information that can provide data on threshold levels, status and evolution of relevant physical, chemical, biological and anthropogenic processes. Existing studies have taken a global perspective, and most have dealt with rangeland conditions. Moreover, the zones usually studied have included countries whose socio-economic and cultural backgrounds differ from those prevailing in Europe. This paper presents a methodology and discussion of indicator requirements, selection and definition, procedures for measuring or making estimates, sensitivity, range of values and interactions. Emphasizing the need to use indicators to develop a system of desertification evaluation, this paper outlines the advantages and difficulties of using such an evaluation system. (C) 1998 Academic Press Limited.