تقييم تسع نماذج لتقدير البخر–نتح المرجعي في منطقة تراغن جنوب غرب ليبيا

Abstract EN

This research was carried out to evaluate nine reference evapotranspiration, and find out an alternative models to the standard FAO Penman-Monteith model in Traghen re- gion southwest of Libya.

The models applied were standard FAO Penman-Monteith, FAO Radiation, FAO Blaney-Criddle, Hargreaves-Samani, Priestley-Taylor, Makkink, Turc, Thomthwaite, Kharrufa and McCloud.

The models were compared with the FAO Penman- Monteith model using root mean square error (RMSE), mean bias error (MBE), Pearson type goodness of fit index (R‘), refined index of agreement (dr), modeling efficiency (Ef) and t-test.

Results showed that FAO Radiation and FAO Blaney-Criddle models overestimated ET0 by values ranged from 0.64% to 16.06%.

However, Kharrufa and McCloud models overestimat- ed ET0 in some months and underestimated ET0 in some other months.

Whereas, the other models underestimated ETC by values ranged from -86.69 % to -6.02%.

The FAO radiation model gave the highest dr (0.892) and Ef (0.951) values, and the lowest RMSE (0.534 mm/day), indicating that this model was the best alternative to the FAO Penman-Monteith model in the study region, followed by FAO Blaney-Criddle model with dr value of 0.851, Ef value of 0.878, and RMSE value of 0.845 mm/day.

In addition, FAO radiation model showed the second best R2 and MBE values at 0.993 and 0.473, respectively Also, FAO Blaney- Criddle model showed the third best R' value at 0.989.

Therefore, FAO radiation model is ranked the first and FAO Blaney-Criddle model is ranked the second.

According to the statis- tical measures stated above, Turc model ranked the third, Kharrufa model ranked forth.

Mod- els of Hargreaves-Samani, Makkink, Priestley-Taylor, McCloud and Thomthwaite ranked fifth, sixth, seventh, eighth and ninth, respectively.

T-test analysis at 5% level of significance indicated that there is a significant difference between the FAO Penman-Monteith model and all models except Kharrufa and McCloud models.