Détermination de la formule appropriée pour l'estimation de l'évapotranspiration potentielle "ETP" dans une région aride : Application à la station de Béchar (SO Algérien).

The sustainable management of water resources requires a good command of the quantitative assessment of the terms of the hydrological balance, such as evapotranspiration, which is a relatively difficult parameter to estimate, especially in the presence of several empirical expressions, making the choice a delicate one. In the arid region of Béchar (south-west Algeria), which suffers from a lack of rainfall and an ever-increasing demand for water as a result of demographic pressure and agricultural activity, evapotranspiration is the main factor of water loss. The aim of this work is to select the most appropriate method for calculating evapotranspiration by comparing several methods. Evapotranspiration is estimated using different methods (Turc, Thornthwaite, Blaney-Criddle, Penman, Penman-FAO and ANRH) over a series from 1978 to 2010 (32 years) based on climatic data (temperature, relative humidity, precipitation, sunshine duration and wind speed). The results indicate that on a monthly scale for the Béchar station, the TURC model provides the best quantitative estimate of potential evapotranspiration (ETP). [ABSTRACT FROM AUTHOR]