Résumé
In the context of the rapid increase of climate change stressors, the Mediterranean coastal areas are threatened by declining of biodiversity and degradation of natural landscapes. The IPCC 2014 report identified the Mediterranean Sea as a hot spot region from human-driven global warming estimated to +2°C for 2050. However, the increase of the heatwave’s frequencies and the Sea Surface Temperatures (SST) during the last summer reveals that this situation is underestimated with the SST 2024 anomaly record of +5.9°C (Copernicus Marine). The Observatory Medjerda LIttoral (OMELI) initiative focuses on addressing coastal degradation in North Africa's semi-arid regions, specifically the Ghar El Melh Lagoon in Tunisia, which suffers shoreline retreat, water quality decline, and serious disruptions of biodiversity indicators resulting in the weakening and loss of its ecosystem services due to climate change and anthropogenic activities like dam construction and pollution. The Ghar El Melh Lagoon, a demosite of the UNESCO Ecohydrology Program, is a pilot area to monitor and restore the coastal ecosystem. The initiative assesses river flow, sediment transport, coastal erosion, and other indicators of ecosystem health to design Nature Based Solutions (NbS) interventions that offset disturbances while improving community resilience. Activities included capacity building, stakeholder engagement, and cross-border cooperation for knowledge exchange in water management and disaster risk reduction. The OMELI-involved projects also aim to generate science-based policy frameworks to integrate wetlands conservation into climate adaptation.Through a combination of data-driven forecasting and on-site measures, OMELI team seeks to establish a sustainable restored wetland for coastal management, addressing the pressing needs of the Mediterranean region's vulnerable ecosystems and communities. Aligned with the UNESCO International Hydrological Program (IHP-IX) strategy, the OMELI initiative focuses on sustainable water management and ecosystem-based approaches, enhancing effectiveness and scalability.