Science et changements planétaires / Sécheresse


Hydropluviometric fluctuations of the Tafna watershed at Beni Bahdel (North West of Algeria) Volume 21, issue 2, avril-mai-juin 2010


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Université Aboubekr Belkaid Faculté de technologie Département d'hydraulique BP 230 Tlemcen 13000 Algérie, Institut national des sciences appliquées de Strasbourg 24, boulevard de la victoire67084Strasbourg France

The Tafna watershed at Beni Bahdel, located in North-West Algeria with a land area of 1,016 km 2, collects a mean annual rainfall of 469 mm, computed over a period of 66 years (1939-1940 to 2004-2005). This basin, like most of the Maghreb, has been undergoing a persistent drought for a few decades. In order to show the severity of this drought, we intend to study fluctuations in rainfall and water flow in this basin during the period mentioned above. Despite the fact that the period between 1943-1944 and 1974-1975 was mainly wet, there has been a dramatic decrease in pluviometric values since 1974-1975. This deficiency, estimated at 27% relative to the wet period, results in a 69% decrease in water flow. A prevalence of evapo-transpiration over the other terms of hydrologic assessment can be expected. On the other hand, it has been established that the dry period is characterized by a greater aptitude to flow compared to the wet period.