The paradoxical increase of Mediterranean extreme daily rainfall in spite of decrease in total values

• Published in: Geophysical research letters Vol. 29; no. 11; pp. 31-1 - 31-4
• Main Authors: Alpert, P., Ben-Gai, T., Baharad, A., Benjamini, Y., Yekutieli, D., Colacino, M., Diodato, L., Ramis, C., Homar, V., Romero, R., Michaelides, S., Manes, A.
• Format: Journal Article
• Language: English
• Published: American Geophysical Union 01-06-2002; Blackwell Publishing Ltd
• Subjects: Categories; Climate dynamics; Coherence; Extreme values; Flash flooding; Floods; Geophysics; Global Change; Hydrology; Precipitation; Rainfall; Trends; Water management; MED, Israel; MED, Italy; MED, Cyprus; Spain
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2001GL013554

Earlier reports indicated some specific isolated regions exhibiting a paradoxical increase of extreme rainfall in spite of decrease in the totals. Here, we conduct a coherent study of the full‐scale of daily rainfall categories over a relatively large subtropical region‐ the Mediterranean‐ in order to assess whether this paradoxical behavior is real and its extent. We show that the torrential rainfall in Italy exceeding 128 mm/d has increased percentage‐wise by a factor of 4 during 1951–1995 with strong peaks in El‐Nino years. In Spain, extreme categories at both tails of the distribution (light: 0‐4 mm/d and heavy/torrential: 64 mm/d and up) increased significantly. No significant trends were found in Israel and Cyprus. The consequent redistribution of the daily rainfall categories ‐torrential/heavy against the moderate/light intensities ‐ is of utmost interest particularly in the semi‐arid sub‐tropical regions for purposes of water management, soil erosion and flash floods impacts.