A systematic review of the applications of the mediterranean desertification and land use model for assessing desertification sensitivity

The Mediterranean Desertification and Land Use (MEDALUS) model, originally developed in 1999, has become one of the most widely adopted frameworks for assessing and mapping desertification sensitivity globally. Despite its widespread and growing application across diverse geographic and climatic contexts, no systematic review of its global implementation has previously been conducted. This study addresses that gap through a systematic review of peer-reviewed literature published between 1999 and 2024, following PRISMA 2020 guidelines. The review evaluated the temporal evolution and geographic distribution of MEDALUS applications, the frequency and nature of model modifications, indicator selection and data sourcing practices, validation approaches, and classification schemes employed across studies. Seventy-three eligible studies were identified from an initial pool of 262 records. Key findings reveal a marked increase in applications from 2013 onwards, with single-year assessments dominating the literature. North Africa and the Middle East account for the largest share of applications, while major dryland regions such as Central Asia and East Africa remain entirely unrepresented. Model modifications were nearly universal at the indicator level, with available evidence suggesting that data availability frequently influenced indicator selection alongside local environmental considerations. Validation of Environmentally Sensitive Area Index (ESAI) outputs remains critically underperformed, with only 6 studies conducting any form of independent assessment. Poorly documented weighting procedures, inconsistent classification schemes, and limited transparency in management indicator reporting represent the most pressing methodological challenges facing the framework. The review provides actionable guidance for improving the scientific rigor, reproducibility, and policy relevance of future MEDALUS applications.