A Continental-Scale tracking for mobile drought dynamics across Africa using Multivariate drought Index Fusion

• Multivariate Drought Index Fusion (MDIF) was developed with integrating NDVI, LST, precipitation, SPEI, and VHI using PCA. • The tracked mobile drought fronts across Africa (2000–2024) provided the first continental-scale drought movement dynamics. • Dominant northeast-to-southwest drought propagation was identified with peak front speeds exceeding 180 km/month in Southern Africa. • MDIF was validated against SPI-3 with showing strong correlation (r = 0.72–0.84), especially in arid and semi-arid regions. Drought remains the most widespread and debilitating climate hazard in Africa, which threatens food safety and socio-ecological stability across the continent. Traditional drought monitoring systems, however, typically never register the dynamic evolution of drought episodes, which can extend between areas and amplify effects downstream. This study proposes a new Multivariate Drought Index Fusion (MDIF) that, apart from merging different drought indicators, mainly tracks the spatiotemporal trajectory of mobile drought fronts across Africa from 2000 to 2024. Avoiding the shortcomings of static drought maps, this approach offers a dynamic presentation of drought propagation patterns required for timely warning and management. Through the use of Principal Component Analysis (PCA), MDIF integrates multiple drought indicators, Normalized Difference Vegetation Index (NDVI), Land Surface Temperature (LST), precipitation, Standardized Precipitation-Evapotranspiration Index (SPEI), and Vegetation Health Index (VHI), into a fused, highly reliable, meteorological-ecological sensitivity drought index. The MDIF exhibited significant correlations with SPI-3 (r = 0.72–0.84), particularly across arid and semi-arid regions, and with VHI (r = 0.76–0.87), further underscoring its robustness in capturing both meteorological and ecological drought conditions. The findings indicate the Horn of Africa as a long-term drought hotbed, with severe events during 2006, 2011, 2017–2019, and 2022–2023, while Southern Africa experienced severe multi-year droughts from 2014 to 2017. Our tracking analysis, for the first time, indicates a dominant northeast-to-southwest trajectory of drought fronts over sub-Saharan Africa. This research enhances continental drought early warning through dynamic mapping of intensity and mobility for resilience planning.