Spatiotemporal Characterization Of The Annual Rainfall In Setif Region-algeria

The annual rainfall in Sétif during 1970-2011 series reveals a spatial pattern oriented north-east/south-west, with annual average of 458 mm. A positive trend of rainfall is noted between 1970-1990 and 1991-2011 sub periods, with annual records of 442 mm and 456 mm respectively. Based on 5 rainfall classes of 150 and 250mm for each, precipitation maps best illustrate the rainfall pattern. However, rainfall probability maps are performed on the basis of exceeding annual threshold of 400 mm. The variability is increasingly observed during the period 1991-2011 for the central zone of the study area. There is also a shift of the barycenters of the rainfall classes and shrinkage of the humid zone in the north between the two sub periods 1970-1990 and 1991-2011.