Résumé
Lebanon, Middle-East
While recent drought assessments predominantly rely on international meteorological indices, agro-environmental impacts are more closely linked to the diverse facets of drought derived from daily soil moisture depletion. This study investigates how recent climate change (1960–2020) has differentially affected drought facets in Lebanon. The DFEAT tool (Drought FEature Assessment Tool) was employed, which utilizes a daily soil water content time series derived from the empirical KBDI (Keetch-Byram Drought Index), to extract and analyze yearly trends in these drought facets, including onset/offset timings, duration, peak drought timing and severity value, and soil drying/rewetting rates.
A gradual shift toward drier conditions was revealed by the analysis, marked by a 5-day delay in drought offset and a significant earlier onset by 17 days. This trend emerges under annual precipitation stability but a seasonal redistribution, enhanced by rising temperatures. These changes have resulted in more prolonged drought episodes, extending by 15 days over the coastal areas and becoming more pronounced in the arid eastern regions of the country. Additionally, an increase in peak drought severity by 3 mm, a marginal rise in soil moisture drying rates by 0.096 mm.day−1, and a total reduction in the intensity of autumnal rainfall pulses by 10 mm were observed. The escalating drier pattern underscores the need for adaptive management strategies in Lebanon’s drought-prone sectors.
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•Monitoring regional spatiotemporal drought trends benefits from considering its multiple facets.•Precipitation trends are non-significant over the period 1960–2020, while temperature shows a significant increase.•Rising temperatures play a dominant role in shaping regional drought trends in Lebanon.•Modest increases in drought duration are observed, driven by significantly earlier drought onset occurrences.•Despite a non-significant trend in offset timing, earlier drought occurrence intensifies significantly peak drought severity.