Evolutions Concerning The Concentration Of Daily Precipitation On The Coast Of The Western Mediterranean Basin (1951-2010)

In this paper, the nonparametric MANN-KENDALL test is used to detect the trends of the annual values of the daily precipitation concentration index (CI1) recorded in the coastal areas of the western Mediterranean Sea. Daily series of 45 meteorological observatories distributed in a relatively uniform way to the coastal lands of the western Mediterranean Sea and the Balearic Islands, Corsica, Sardinia and Sicily of the period of 60 years (1951-2010) were analyzed. The results reveal significant changes of the annual concentration index (CI1) of the daily precipitation for the complete period and two sub-periods of 30 years studied (1951-1980 and 1981-2010). Over the full period, ten stations out of thirty show a significant positive evolution of the index and only two significant negative developments. The same trend is evident in the sub-period 1981-210 (25.6 % of stations with significant positive developments). But the lack of homogeneity of the results does not lead to the conclusion of a general change in the distribution of daily rainfall.