Analysis and trends of rainfall amounts and extreme events in the Western Mediterranean region

Abstract

Since the dawn of civilization, the Western Mediterranean region has been a unique path for encounters and exchanges. The stability of the general conditions prevailing in its surrounding was crucial to ensure this vital link between north and south and east and west. However, any imbalance would be the precursor of a harmful domino effect to these environments, where the natural vulnerabilities are combined to a worsening socioeconomic congestion. In both banks, efforts are made not to give way to the fragile balance of water availability and risks. Here, we show that the amount and recurrence of extreme rainfall events contradict with current management scenarios. Our pixel-based assessment of the rain components extracted from the African Rainfall Climatology product reveals an annual increase in the total amount of rainfall and extreme rainfall events. A spatial and a trend analysis of the studied rainfall components were carried out to determine their spatial patterns and magnitude. The cumulative annual rainfall alone will not mean if a year is dry or wet. A wet year can experience great periods of drought, which will have serious repercussions on the socioeconomic and ecological levels. In addition, the increased occurrence of extreme rains can produce floods, intensifying land degradation processes, loss of biodiversity, water availability and economic growth. Decision-makers should be aware that current models of territorial management will not be able to cope with this change and that interdisciplinary cohesion and cross-border actions are the most appropriate solution.