Comparison of Standardized Reference Evapotranspiration Equations in Southern Spain

ASCE and FAO-56 standardized reference evapotranspiration ( ET0 ) equations were compared using data from 31 meteorological stations in Andalusia, Southern Spain. Comparisons were made between daily ET0 obtained by summing hourly standardized ASCE–Penman–Monteith estimations and calculated from the addition of hourly FAO56–Penman–Monteith estimations, daily ET0 estimated on a daily basis, and calculated by the Hargreaves equation. On an hourly basis, the FAO-56 version estimated lower than the ASCE version as 6% in some locations, with a difference of 4% on the average, mainly due to the higher surface resistance (70 s m−1 ) used in the FAO-56 version during daytime periods, as opposed to the 50 s m−1 rs value used by the ASCE version. Differences between both estimates were higher when evaporative demand increases. The level of agreement improved when the two computational time steps were compared, because differences were lower (2% on the average) and did not depend on the wind speed or ET0 values. The ...

[1]  L. S. Pereira,et al.  A recommendation on standardized surface resistance for hourly calculation of reference ETo by the FAO56 Penman-Monteith method , 2006 .

[2]  C. Willmott.  Some Comments on the Evaluation of Model Performance , 1982 .

[3]  Terry A. Howell,et al.  Conversion between evapotranspiration references and methods. , 2000 .

[4]  George H. Hargreaves,et al.  Reference Crop Evapotranspiration from Temperature , 1985 .

[5]  A. Martínez-cob,et al.  A wind-based qualitative calibration of the Hargreaves ET0 estimation equation in semiarid regions , 2004 .

[6]  Qi Hu,et al.  Quality control of daily meteorological data in China, 1951–2000: a new dataset , 2004 .

[7]  W. O. Pruitt,et al.  Crop water requirements , 1997 .

[8]  Zohrab Samani,et al.  Estimating solar radiation and evapotranspiration using minimum climatological data , 2000 .

[9]  Baryohay Davidoff,et al.  Comparison of Some Reference Evapotranspiration Equations for California , 2005 .

[10]  P. Steduto,et al.  Daily reference evapotranspiration estimates by the Penman-Monteith equation in Southern Italy. Constant vs. variable canopy resistance , 2003 .

[11]  Ayse Irmak,et al.  Solar and Net Radiation-Based Equations to Estimate Reference Evapotranspiration in Humid Climates , 2003 .

[12]  I. Lorite,et al.  Regional calibration of Hargreaves equation for estimating reference ET in a semiarid environment , 2006 .

[13]  P. Gavilán,et al.  Reference Evapotranspiration Estimation in a Highly Advective Semiarid Environment , 2005 .

[14]  Juan Vicente Giráldez,et al.  Assessing Reference Evapotranspiration by the Hargreaves Method in Southern Spain , 2004 .

[15]  Richard G. Allen,et al.  Assessing Integrity of Weather Data for Reference Evapotranspiration Estimation , 1996 .

[16]  Jerry L. Hatfield,et al.  Data quality checking for single station meteorological databases , 1994 .

[17]  Richard G. Allen,et al.  Estimating Reference Evapotranspiration Under Inaccurate Data Conditions , 2002 .

[18]  Brent Clothier,et al.  ESTIMATION OF SOIL HEAT FLUX FROM NET RADIATION DURING THE GROWTH OF ALFALFA , 1986 .

[19]  R. L. Snyder,et al.  An evaluation of common evapotranspiration equations , 1999, Irrigation Science.

[20]  Richard G. Allen,et al.  Comparison of Reference Evapotranspiration Calculations as Part of the ASCE Standardization Effort , 2003 .

[21]  Mladen Todorovic,et al.  Single-Layer Evapotranspiration Model with Variable Canopy Resistance , 1999 .

[22]  R. Allen,et al.  History and Evaluation of Hargreaves Evapotranspiration Equation , 2003 .

[23]  R. Ziemer.  Evaporation and transpiration , 1979 .

[24]  S. Idso,et al.  Analysis of an empirical model for soil heat flux under a growing wheat crop for estimating evaporation by an infrared-temperature based energy balance equation , 1987 .

[25]  Richard G. Allen,et al.  STANDARDIZED ASCE PENMAN-MONTEITH: IMPACT OF SUM-OF-HOURLY VS. 24-HOUR TIMESTEP COMPUTATIONS AT REFERENCE WEATHER STATION SITES , 2005 .

[26]  Christopher A. Fiebrich,et al.  Quality Assurance Procedures in the Oklahoma Mesonetwork , 2000 .

[27]  José O. Payero,et al.  ESTIMATING SOIL HEAT FLUX FOR ALFALFA AND CLIPPED TALL FESCUE GRASS , 2005 .

[28]  L. S. Pereira,et al.  Crop evapotranspiration : guidelines for computing crop water requirements , 1998 .