Three decades of vegetation change in Jabel Marra: climate drivers and post-conflict vegetation dynamics

Abstract

Understanding long-term vegetation dynamics in semi-arid and conflict-affected environments is important for sustainable land management and climate adaptation. This study investigated vegetation change and climate variability in the Jabel Marra region of Central Darfur, Sudan, during 1994–2024 using Landsat-derived Normalized Difference Vegetation Index (NDVI), CHIRPS precipitation, MERRA-2 temperature, and the Standardized Precipitation Evapotranspiration Index (SPEI). Long-term vegetation trends were assessed using the Mann-Kendall trend test and Sen’s slope estimator, whereas climate–vegetation relationships were evaluated using correlation analysis. The annual NDVI showed a significant positive trend (Mann–Kendall Z = 4.78, p < 0.001), with a Sen’s slope of 0.00143 NDVI units year⁻¹, indicating a gradual increase in vegetation greenness. Spatial trend analysis showed that positive vegetation trends were concentrated primarily in mid-to-high elevation vegetated areas. Annual precipitation exhibited substantial interannual variability (R² = 0.06), whereas temperature increased consistently (R² = 0.51). NDVI was positively correlated with precipitation (r = 0.48) and negatively correlated with temperature (r = − 0.57). The SPEI identified recurrent drought episodes before 2018, followed by predominantly wetter conditions thereafter. The findings indicate that vegetation dynamics in Jabel Marra were primarily associated with climatic variability, particularly precipitation and drought conditions, while conflict-related processes were considered contextual because they were not directly analyzed. This study demonstrates the value of integrating long-term satellite observations and climate datasets to monitor vegetation changes in data-scarce dryland environments.