Results 221 to 230 of about 9,210 (256)

Defining and Using Reference Evapotranspiration

Journal of Irrigation and Drainage Engineering, 1994
Values of reference evapotranspiration (ET0) are used with crop coefficients (KC) for many aspects of irrigation and water resources planning and management. More than a score of methods are used for estimating ET0. Estimated values vary widely due to the lack of standardization of the reference.
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Reference and Crop Evapotranspiration in South Central Nebraska. I: Comparison and Analysis of Grass and Alfalfa-Reference Evapotranspiration

Journal of Irrigation and Drainage Engineering, 2008
In Nebraska, historically, there have been differences among the water regulatory agencies in terms of the methods used to compute reference evapotranspiration ( ETref ) to determine actual crop water requirements and hydrologic balances of watersheds.
A. Irmak, S. Irmak, D. L. Martin
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ASCE's Standardized Reference Evapotranspiration Equation

Watershed Management and Operations Management 2000, 2001
The ASCE Evapotranspiration in Irrigation and Hydrology Committee (ASCE-ET) is recommending, for the intended purpose of establishing uniform evapotranspiration (ET) estimates and transferable crop coefficients, two Standardized Reference Evapotranspiration Surfaces : (1) a short crop (similar to grass) and (2) a tall crop (similar to alfalfa), and
I. A. Walter, R. G. Allen, R. Elliott, M. E. Jensen, D. Itenfisu, B. Mecham, T. A. Howell, R. Snyder, P. Brown, S. Echings, T. Spofford, M. Hattendorf, R. H. Cuenca, J. L. Wright, D. Martin   +14 more
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Reference Crop Evapotranspiration from Temperature

Applied Engineering in Agriculture, 1985
MEASURED lysimeter evapotranspiration of Alta fescue grass (a cool season grass) is taken as an index of reference crop evapotranspiration (ETo). An equation is presented that estimates ETo from measured values of daily or mean values of maximum and minimum temperature. This equation is compared with various other methods for estimating ETo.
null George H. Hargreaves, null Zohrab A. Samani   +1 more
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An update for the definition of reference evapotranspiration

1994
International ...
Allen, R.G., Smith, M., Perrier, A., Pereira, L.S.   +3 more
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FAO‐24 Reference Evapotranspiration Factors

Journal of Irrigation and Drainage Engineering, 1991
Improved equations are presented tor calculating correction factors for the United Nations Food and Agriculture Organization Irrigation and Drainage Paper Number 24 (FAO‐24) grass reference evapotranspiration methods. Equations duplicate tables of correction factors contained in the original FAO‐24 report and simplify development of computer ...
Richard G. Allen, William O. Pruitt
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Spatial variability of reference evapotranspiration in Greece

Physics and Chemistry of the Earth, Parts A/B/C, 2002
Abstract Optimal interpolation using geostatistical techniques, such as kriging, can be used for contouring and mapping of regionalized variables. In this study spatial variability of reference evapotranspiration over Greece is investigated using geostatistics. An exponential semivariogram model with only one pair of drift coefficients is used as the
Nicolas R Dalezios, Athanasios Loukas, Dimitrios Bampzelis   +2 more
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An update for the calculation of reference evapotranspiration

1994
International ...
Allen, R.G., Smith, M., Pereira, L.S., Perrier, A.   +3 more
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Accuracy of reference evapotranspiration forecast

2000
The ability to forecast reference evapotranspiration (ETo) accurately greatly enhances our ability to manage the irrigation of high-frequency irrigation systems. If the synoptic and mesoscale models are accurate, then ETo predictions from the forecasts are likely to be more accurate than statistical models.
Duce P, Snyder RL, Spano D
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Accuracy of Estimated Reference Crop Evapotranspiration

Journal of Irrigation and Drainage Engineering, 1989
Evapotranspiration from cool‐season grasses is used as the reference for ET0. The requirements for local calibration for three equations for ET0 recommended by the Food and Agriculture Organization of the United Nations (FAO) are shown for different climatic regions of California.
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