Recommended citation: Sori, R., Stojanovic, M., Pérez-Alarcón, A., Mohamed, M. S., Mekhiel, A. F. S., Nieto, R., Gimeno, L. (2025). Seasonal Compound Drought Typologies and Hazard in Northern Africa during the 1980–2023 period. MedGU Annual Meeting. Athens, Grece, 10-12 November 2025.

Abstract

Northern Africa encompasses Mediterranean woodlands, semi-arid rangelands, and intensively farmed lowlands, making it highly sensitive to the impacts of drought and becoming a hotspot in recent years. Using ERA5-Land Reanalysis and Euro-pean Space Agency data for the 1980–2023 period, we derive 3-month Standardised Precipitation (SPI3), Standardised Precipita-tion–Evapotranspiration (SPEI3) and a 3-month Standardised Soil Moisture Index (SSMI3), to first build a drought typology and then map monthly compound-drought hazard. Typologies are defined with strict thresholds for drought conditions (<- 0.84), and wet conditions (> 0.84) via mutually exclusive logical rules: Compound (SPI, SPEI and SSMI all below drought threshold), Hydrological (SSMI and SPI<-0.84, SPEI > 0.84), Evapotranspiration-driven (SSMI, SPEI<-0.84; SPI > 0.84) and Soil-anomaly hydrology (SSMI<-0.84, SPI and SPEI > 0.84). This analysis was performed for indices values of February, May, August and November, chosen because at a 3-month ac-cumulation they typify winter, spring, summer and autumn. Complementarily, monthly compound-drought hazard is quanti-fied, for each anchor month and grid cell, as the empirical fre-quency that SPI3, SPEI3 and SSMI3 fall simultaneously below −0.84 and is classified into five spatial-percentile levels. The results reveal that the compound drought forms pronounced hot-spots over Morocco, northern Algeria, Tunisia, whereas hy-drological type is the most spatially extensive along the Maghreb belt, and Evapotranspiration and Soil-anomaly types are rare and patchy, consistent with episodic heat-demand effects and local soil–land-use controls on both sides of the Nile riverbed. In addi-tion, a coherent hazard belt along the northern African Mediter-ranean margin, with the highest relative hazard in northwestern Africa, is observed in all seasons, with maxima in winter and spring. By distinguishing how drought manifests (typology) and how often multivariate deficits co-occur (hazard), this frame-work delivers transparent, reproducible and transferable diagnos-tics to support risk-informed decision-making across water allo-cation, drought preparedness for rain-fed agriculture and the stewardship of Mediterranean forests, thereby strengthening the resilience of ecosystems and livelihoods in this socio-economically vital region.