An estimation of evapotranspiration by simple models in the semi arid Mediterranean zone of the North-West of Algeria

Four temperature-based evapotranspiration models were applied and compared to daily measurements obtained by a Piche evaporimeter in a Mediterranean climate zone of the semi arid type in the North-West of Algeria. Direct measurements of evaporation obtained by Piche on five stations were corrected by the Bouchet model. Evapotranspiration was calculated according to the following models: Blaney-Criddle, Blaney-Criddle (SCS), Linacre and Romanenko. The results showed that the best model is the Blaney-Criddle (SCS) one which gave excellent results for almost all of the stations studied, presenting the lowest statistical parameters [root mean squared error (RMSE), mean bias error (MBE) and t-statistic and a higher index of agreement (d). The Blaney-Criddle (SCS) also showed the lowest overestimation of evapotranspiration compared with other models. Therefore, the Blaney-Criddle (SCS) model is the most suitable model for estimating the daily evapotranspiration when direct evaporation measurements are not available.