Etude de la variation spatiotemporelle des précipitations dans le Nord-Est algérien.

Abstract

Precipitation variability is one of the most important elements for climate and hydrometeorological studies. North African countries, and specifically Algeria, have an increased sensitivity to climate variability, particularly the precipitation, due to its effect on economic, social and demographic structure. In the present study, the main objective is to contribute to a better understanding of the spatial and temporal variability of rainfall for 22 meteorological stations distributed in Northeastern Algeria for the period1978-2010. The results showed that, spatially, precipitation decreases from North to South and from East to West. The application of the Mann–Kendall test to the time series data showed that for annual precipitation, no station showed statistically significant trends, unlike the number of rainy days, where there was a significant negative trend in four stations (Jijel, Constantine, Oum El Bouaghi and Tébessa). For the monthly time series, significant positive trends were observed during the months of September in the coastal stations and July for the plateaus and southern Saharan Atlas stations, while significant negative trends were recorded during the months of February and March for the stations of the extreme East in the study area. The regionalization of stations in northeastern Algeria based on inter-annual variability through Principal Component Analysis (PCA) and Hierarchical Ascending Classification (HAC) has identified five distinct groups of stations for the period 1978-2010. These results revealed that for the period analyzed, there was no significant climate change in northeastern Algeria but there is a seasonal delay.