Assessing Land Degradation Neutrality (LDN) in Southeastern Tunisia Based on Earth Observation Data and Open Source Applications

Land Degradation Neutrality (LDN) is a new approach, which is receiving considerable interest worldwide, in assessing current land condition. An LDN assessment was undertaken for the Dhahar-Jeffara transect in southeastern Tunisia. The assessment was performed following the United Nations Convention to Combat Desertification (UNCCD) method in terms of three indicators: land cover, land productivity and soil organic carbon. Over a 20-year period (1999–2018), satellite data, Geographic Information Systems (GIS), and Open Source applications were used to assess the changes in these indicators. As a result, the LDN baseline status was evaluated across the region to better understand its distribution, to evaluate trends as well as drivers of land degradation, and eventually identify “hot-spots”, targeted for restoration options and used to achieve the Sustainable Development Goal (SDG15.3) by 2030 in the studied area. The Trends.Earth tool under the QGIS software has been explored to support UNCCD-LDN indicators. Based on the three derived indicators, the majority of the study area (89%) showed clear stability toward the land degradation process. Only 3% (7330 ha) of the Dhahar-Jeffara transect were identified as degraded land areas; however, 8% (17860 ha) are identified as improved (not degraded) land. This study recommends the implementation of an LDN target setting at a regional level, in addition to targeting land degradation drivers behind the land degradation process by implementing different sustainable land practices to tackle this phenomenon.