Identification of rainfall onset for meteorological use regarding to region in the Algerian highlands

Keywords: meteorology, weather, El-Niño, rainfall, forecast


The data from several weather stations in Western Algeria show a semi-arid climate during last decades. The entire study region showed a great variability in the occurrences of the first and second rainy days in the year. This variability is associated with a positive trend, showing a continuous increasing aridity in the south Mediterranean and the late arrival of the rainy season is well marked. The rainy season in the north of Algeria, spreads from September to June. The origin of the rains differ according to the seasons. The rainfall from June to October is of localized stormy origin, whereas in winter, the rainfall comes from the classical atmospherically perturbations arriving from North or North West. This work objective was to give a definition of the rainy season onset and to show its inter - annual variability according to the Niño and Niña years. The El - Niño phenomenon by its positive and negative phases seems to affect the start of the rainy season. The variability of the rainfall onset indices is very significant. There is a relative stability of the rainy season length over the long term period. A significant delay in the precipitation onset was observed during certain years. A method to define rainy season onset based on daily rainfall data from a weather station in the Algerian highlands was proposed. This approach is based on a climatic point of view, using a frequency analysis of precipitation and dates of their first occurrence. It delays the first heavy rain day (20 mm) when La - Niña settles. If EL-Niño settles, the first heavy rain (20 mm) day will be earlier. These results will improve the probabilistic forecasts of the beginning of the rainy seasons, the cessation as well as the lengths. This work is a preliminary confirmation that the El-Niño phenomenon really affects the Mediterranean climate.

Author Biographies

Lazreg Benaichata
Ibn Khaldoun university
Mahmoud Houari
National Office of Meteorology
Mhamed Maatoug
Ibn Khaldoun university
Mohamed Azzaoui
Higher Agronomic School of Mostaganem
Naceur Khadidja
Ibn Khaldoun university


1. Adams, K.A., Lawrence E.K. 2019. Research Methods, Statistics and Applications, Sage Publi., Calif. Second Edition. 672 p.
2. Ati O.F., Stigter C..J., Oladipo E.O. 2002. A comparison of methods to determine the onset of the growing season in Northern Nigeria. International Journal of Climatology 22: 731–742.
3. Aviad Y., Kutiel H., Lavee H. 2004.Analysis of beginning, end and length of the rainy season along a Mediterraneen–arid climate transect for geomorphic purposes. Journal of Arid Environments. 59, 189-204.
4. Balme M., Galle S., Lebel T. 2005. Démarrage de la saison des pluies au Sahel: variabilité aux échelles hydrologique et agronomique, analysée à partir des données EPSAT-Niger. Sécheresse, 16 (1), 15-22.
5. Belaid D. 1996. Aspects de la céréaliculture Algérienne. Ed. Office des publications universitaires, BenAknoun (Alger), 206 p.
6. Benaichata L., Mederbal K., Chouieb M. 2015. Climate Change Detection with Extreme Weather Factors Concerning Algeria. ESJ. 11: 220-232.
7. Benoit, P., 1977. The start of the growing season in northern Nigeria. Agric. Meteorol. 18, 91–99.
8. Camberlin P. Janicot S., Poccard, I. 2001. Seasonality and atmospheric dynamics of the teleconnection between African rainfall and tropical sea-surface temperature: Atlantic vs. ENSO, International Journal of Climatology, 21(8), 973 - 1005.
9. Camberlin P., Diop M., 2002. Application of daily rainfall PCA to the assessment of the rainy season characteristics in Senegal. Climate Research.
10. Cook G.D., Heerdegen R.G., 2001. Spatial variation in the duration of the rainy season in monsoonal Australia. International Journal of Climatology, 21, 1723 - 1732.
11. Cornillon P.A., Guyader A., Husson F., Jélou N., Josse J., Kloareg M., Matzner - Lober E., Rouvière L. 2012. Statistiques avec R. Presse Universitaire de Reines.
12. Curtis S. 2008. The El-Nino southern oscilation and global precipitation. Geogr.Compass, 2, 600-619.
13. Dodd D.E.S, Joliffe I.T. 2001. Early detection of the start of the wet season in semiarid tropical climates of western Africa. International Journal of Climatology, l21: 1251-1262.
14. Essotalani A., Kossi M., Badameli S., Dubreuil V., 2010. Evolution of rainy seasons potentially useful for Togo on the 1950-2000 period, Climatologie, 89-107.
15. Fitzpatrick, R.G., Bain, C.L., Knippertz, P., Marsham J.H., Parker, D.J. 2015. The West African monsoon onset : A concise comparison of definitions, Journal of Climate, 28(22), 8673-8694.
16. Hapuarachchi H.A.S.U., Jayawardena I.M.S.P. 2015. Modulation of seasonal rainfall in Sri Lanka by ENSO extremes.Sri Lanka Journal.of Meteorology.Vol.1:3-11
17. Joseph P.V., Eischeid J.K., Pyle R.J., 1994. International variability of the onset of the Indian Summer monsoon and its association with atmospheric features, El Nino, and sea surface temperatures. Journal of Climate, 7: 81-105.
18. Marega O. 2016. Changements socio-environnementaux et évolution des pratiques agropastorales en Afrique sahélienne : étude comparée entre le Ferlo (Sénégal), le Gourma (Mali) et le Fakara (Niger)», thèse de doctorat, Université Diderot - Paris 7, 700 p.
19. Marteau R., Benjamin Sultan B., Moron V., Baron C., Traoré S.B. 2010. Démarrage de la saison des pluies et date de semis du mil dans le sud-ouest du Niger. XXIIIe colloque de l’Association Internationale de Climatologie. Risques et changement climatique:379-384.
20. Reiser H., Kutiel H. 2007. The rainfall regime and its uncertainty in Valencia and Larnaca. Advances Geosciences, European Geosciences Union,101-106.
21. Seck M., Moussa N.A., Abou M., Wade S., Thomas J.P. 2005. Adaptation aux changements climatiques. L’étude de cas des systèmes de production agricoles de Sébikotane (Sénégal), ENDA TiersMonde, 33 p.
22. Stern, R.D., 1982. Computing a Probability Distribution for the Start of the Rains from a Markov Chain Model for Precipitation. Journal Applied Meteorology, 21, 420–423.
23. Trenberth K.E.,Hoar T.J. 1997. El Nino and climate change.Geophys.Res. Lett., 24, 3057-3060.
How to Cite
Benaichata, L., Houari, M., Maatoug, M., Azzaoui, M., & Khadidja, N. (2019). Identification of rainfall onset for meteorological use regarding to region in the Algerian highlands. Journal of Geology, Geography and Geoecology, 28(1), 106-113.