Résumé:
Rainfall is a fundamental element of the climate. Its importance is such that the different climate classifications are based essentially on the annual or monthly average precipitation, it is necessary to know the recent evolution and variability of the climate in arid and semi-arid regions To better understand the irregularity of precipitation and estimate consequences such as floods and extreme droughts which can cause economic losses and ecological and environmental damage. Although increased precipitation can enhance agricultural production and water supply. We have helped to study the essential element of the balance which is precipitation by using statistical processing and analysis of drought indices, so we have adopted a methodology characterized by the collection of rainfall data and the creation of a computer database.
The calculation of the indices for the different stations reveals the existence of two distinct wet and dry periods, the degree of severity is not too high in our stations, we see that there is a dominance of the wet period classes. From the point of view of the evolution of the rainfall of the stations, we notice that the average increases from West to East.
