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Evaluation of Reference Evapotranspiration Methods in Arid, Semiarid, and Humid Regions
Author(s) -
Gao Fei,
Feng Gary,
Ouyang Ying,
Wang Huixiao,
Fisher Daniel,
Adeli Ardeshir,
Jenkins Johnie
Publication year - 2017
Publication title -
jawra journal of the american water resources association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.957
H-Index - 105
eISSN - 1752-1688
pISSN - 1093-474X
DOI - 10.1111/1752-1688.12530
Subject(s) - evapotranspiration , mean squared error , arid , hydrology (agriculture) , mathematics , unavailability , environmental science , statistics , ecology , geology , geotechnical engineering , biology
It is often necessary to find a simpler method in different climatic regions to calculate reference crop evapotranspiration ( ET o ) since the application of the FAO ‐56 Penman‐Monteith method is often restricted due to the unavailability of a comprehensive weather dataset. Seven ET o methods, namely the standard FAO ‐56 Penman‐Monteith, the FAO ‐24 Radiation, FAO ‐24 Blaney Criddle, 1985 Hargreaves, Priestley‐Taylor, 1957 Makkink, and 1961 Turc, were applied to calculate monthly averages of daily ET o , total annual ET o , and daily ET o in an arid region at Aksu, China, in a semiarid region at Tongchuan, China, and in a humid region at Starkville, Mississippi, United States. Comparisons were made between the FAO ‐56 method and the other six simple alternative methods, using the index of agreement D , modeling efficiency ( EF ), and root mean square error ( RMSE ). For the monthly averages of daily ET o , the values of D , EF , and RMSE ranged from 0.82 to 0.98, 0.55 to 0.98, and 0.23 to 1.00 mm/day, respectively. For the total annual ET o , the values of D , EF , and RMSE ranged from 0.21 to 0.91, −43.08 to 0.82, and 24.80 to 234.08 mm/year, respectively. For the daily ET o , the values of D , EF , and RMSE ranged from 0.58 to 0.97, 0.57 to 0.97, and 0.30 to 1.06 mm/day, respectively. The results showed that the Priestly‐Taylor and 1985 Hargreaves methods worked best in the arid and semiarid regions, while the 1957 Makkink worked best in the humid region.