Can desertification be mapped? Lights and shadows of a challenging task

Abstract

Desertification is a complex and multi-faceted phenomenon. There have been many attempts to map it. However, none of the approaches used over the years has been consolidated, and the criteria and methodologies have changed over the years. This lack of robustness makes the interpretation of these maps confusing and not very operational. In this paper we briefly review the attempts to map this complex environmental problem, analyze its difficulties and show the latest trends. The latest World Atlas of Desertification, published in 2018 by the European Commission, renounces this and proposes an alternative approach. Its proposal is to identify those sites that may be most prone to degradation due to a combination of factors that threaten the balance between resource use and regeneration. The increasing availability of spatial databases opens the door to new approaches. However, this large potential of data must be combined with a clear understanding of the problem, distinguishing between mapping the state of desertification or its risk and determining, as objectively as possible, the thresholds of degradation that lead to persistent degradation.