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| Titel |
Variation in the estimations of ETo and crop water use due to the sensor accuracy of the meteorological variables |
| VerfasserIn |
R. Moratiel, A. Martínez-Cob, B. Latorre |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 13, no. 6 ; Nr. 13, no. 6 (2013-06-03), S.1401-1410 |
| Datensatznummer |
250018490
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| Publikation (Nr.) |
 copernicus.org/nhess-13-1401-2013.pdf |
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| Zusammenfassung |
| In agricultural ecosystems the use of evapotranspiration (ET) to improve
irrigation water management is generally widespread. Commonly, the crop ET
(ETc) is estimated by multiplying the reference crop
evapotranspiration (ETo) by a crop coefficient (Kc).
Accurate estimation of ETo is critical because it is the main
factor affecting the calculation of crop water use and water management. The
ETo is generally estimated from recorded meteorological variables
at reference weather stations. The main objective of this paper was assessing
the effect of the uncertainty due to random noise in the sensors used for
measurement of meteorological variables on the estimation of ETo,
crop ET and net irrigation requirements of grain corn and alfalfa in three
irrigation districts of the middle Ebro River basin. Five scenarios were
simulated, four of them individually considering each recorded meteorological
variable (temperature, relative humidity, solar radiation and wind speed) and
a fifth scenario combining together the uncertainty of all sensors. The
uncertainty in relative humidity for irrigation districts Riegos del Alto
Aragón (RAA) and Bardenas (BAR), and temperature for irrigation district
Canal de Aragón y Cataluña (CAC), were the two most important factors
affecting the estimation of ETo, corn ET
(ETc_corn), alfalfa ET
(ETc_alf), net corn irrigation water requirements
(IRncorn) and net alfalfa irrigation water requirements
(IRnalf). Nevertheless, this effect was never greater than
±0.5% over annual scale time. The wind speed variable (Scenario 3) was the
third variable more influential in the fluctuations (±) of
evapotranspiration, followed by solar radiation. Considering the accuracy for
all sensors over annual scale time, the variation was about ±1% of
ETo, ETc_corn,
ETc_alf, IRncorn, and
IRnalf. The fluctuations of evapotranspiration were higher at
shorter time scale. ETo daily fluctuation remained lower than
5 % during the growing season of corn and alfalfa. This estimation
fluctuation in ETo, ETc_corn,
ETc_alf , IRncorn, and
IRnalf at daily time scale was within an acceptable range, and it
can be considered that the sensor accuracy of the meteorological variables is
not significant in the estimation of ETo. |
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