@article{Alghusni_2020, place={Al Bayda, Libya}, title={ Evaluation of nine reference evapotranspiration models in Traghen region, Southwest of Libya}, volume={35}, url={https://omu.edu.ly/journals/index.php/mjsc/article/view/299}, DOI={10.54172/mjsc.v35i3.299}, abstractNote={<p><strong>&nbsp; </strong>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 region southwest of Libya. The models applied were standard FAO Penman-Monteith, FAO Radiation, FAO Blaney-Criddle, Hargreaves-Samani, Priestley-Taylor, Makkink, Turc, Thornthwaite, Kharrufa and McCloud.&nbsp; 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<sup>2</sup>), refined index of agreement (d<sub>r</sub>), modeling efficiency (E<sub>f</sub>) and t-test.&nbsp; Results showed that FAO Radiation and FAO Blaney-Criddle models overestimated ET<sub>o</sub> by values ranged from 0.64% to 16.06%.&nbsp; However, Kharrufa and McCloud models overestimated ET<sub>o</sub> in some months and underestimated ET<sub>o</sub> in some other months.&nbsp; Whereas, the other models underestimated ET<sub>o</sub> by values ranged from -86.69 % to -6.02%.&nbsp; The FAO radiation model gave the highest d<sub>r</sub> (0.892) and E<sub>f</sub> (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 d<sub>r</sub> value of 0.851, E<sub>f</sub> value of 0.878, and RMSE value of 0.845 mm/day.&nbsp; In addition, FAO radiation model showed the second best R<sup>2</sup> and MBE values at 0.993 and 0.473, respectively&nbsp; Also, FAO Blaney-Criddle model showed the third best R<sup>2</sup> value at 0.989.&nbsp; Therefore, FAO radiation model is ranked the first and FAO Blaney-Criddle model is ranked the second.&nbsp; According to the statistical measures stated above, Turc model ranked the third, Kharrufa model ranked forth.&nbsp; Models of Hargreaves-Samani, Makkink, Priestley-Taylor, McCloud and Thornthwaite ranked fifth, sixth, seventh, eighth and ninth, respectively.&nbsp; 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.</p>}, number={3}, journal={Al-Mukhtar Journal of Sciences}, author={Alghusni, Ali Othman}, year={2020}, month={Sep.}, pages={225–246} }