Changes of the rainfalls rates and the possibility for extremism in Tartous During the period 1970 – 2010 using Gamble's distribution

This research aims to analyze the slope of the general line rates of the annual and quarterly rainfalls in some stations in Tartous, during the period 1970 – 2010 in order to determine the change in rates of rainfalls and the effect of this change on the vary of potential density for the occurrence of extreme rates of rains high or low according to Gamble's distribution about the values ??of extreme rainfall.

The results indicated the presence of a decline in the annual rates of rainfalls at all stations, between 54and 77 mm during the period of this study. Spring recorded statistically the largest important decline where the decline was (86 – 132 mm) while the winter rainfall increased between (27 – 59 mm). The share of Spring of the total annual rainfall fell around 5 – 6% against rising the rates of winter rainfall between 4 – 6%.

The probable density of the high extreme annual Rainfall increased at all stations, according to Gamble's distribution, and there was a significant increase in the likely hood of extreme low rainfall in Spring, which indicates a significant drought in this season. While the probability of Rainfalls increased more in winter so that the winter is wetter than before.