The depressions centered on the northeast of the western Mediterranean have a negative influence on rainfall in Oranien, since their action results in a drought in the west. The matorrals located on the mountainous massifs of northwestern Orania, with the steppes of western Algeria (Beni-Saf, Sidi Djilali, Sebdou, El-Bayadh, El-Aricha, Mecheria, El-Kreider, etc. ...) have been strongly marked by drought. Relying mainly on climatic data, bioclimatic...