Understanding Flash Droughts in Greece: Implications for Sustainable Water and Agricultural Management

Flash droughts—characterized by their sudden development, severity, and short duration—impose considerable challenges on the soil–water complex of agricultural systems, especially under the Mediterranean climate. Though gaining increasing global significance, Mediterranean flash droughts are still understudied. This study examines the spatiotemporal variability of flash droughts in Greece for the period 1990–2024 using 5-day (pentad) ERA5-Land root-zone soil moisture (0–100 cm) at 0.25° resolution. A percentile-threshold approach detected flash drought events, and their main features—including frequency, duration, magnitude, intensity, decline rate, recovery rate, and recovery duration—were evaluated at the annual and seasonal levels. Findings indicate that Central Greece and Thessaly face the highest frequency and longevity of flash droughts, while Western Greece and Peloponnese and Western Macedonia are characterized by rapid development but intense recovery. An innovative empirical classification framework founded on decline and recovery rates indicated that Mild Fast Recovery events prevail in northern and central Greece, while Intense but Recovering events dominate in western and southern Greece. These results offer new perspectives on how flash droughts impact soil–water availability and agricultural resilience, providing a data-driven platform to aid sustainable water management, early warning systems, and adaptation strategies for Mediterranean agriculture in conditions of climate variability.