SECULAR EVOLUTION OF PRECIPITATION IN THE NORTH AFRICAN STEPPE

North Africa is one of the most disadvantaged regions in the world in terms of water resources.In the context of global warming, any water deficit could significantly impact the water balance, particularly in arid areas.Analysis of long-term rainfall patterns, especially in steppe and semi-arid regions, is crucial to anticipate potential effects on water resources and local ecosystems.Previous studies have highlighted a decreasing rainfall gradient across North African countries but were limited by spatial and temporal constraints.This study examines rainfall trends across all North African countries, utilizing 27 gridded statistical series, distributed as follows: 4 in Morocco, 10 in Algeria, and 13 in Tunisia, from the CRU (Climatic Research Unit) at a resolution of 0.5 0.5 (50 km 50 km) from the year 1901 to the year 2022.The data are aggregated by wilayas (local governorates) or departments for a precise analysis of climatic trends.This work is structured around three main hypotheses: (1) Has rainfall in North Africa shown a declining trend?(2) Does a longitudinal drying gradient exist?(3) Can any period be identified during which a break in rainfall homogeneity occurred?The results reveal regional variations.Stations located in Eastern Algeria and Tunisia do not show a long-term decrease in rainfall, while those in Western Algeria and Eastern Morocco indicate a general downward trend.A decreasing gradient from east to west is observed, as well as breaks in homogeneity at certain stations.These results are essential for developing region-specific adaptation strategies to ensure sustainable water resource management in the face of climate change.