Evaluation of pan coefficient for reference crop evapotranspiration for semi-arid region

Gundekar, H. G.; Khodke, U. M.; Sarkar, Shibayan; K., R.

doi:10.1007/s00271-007-0083-y

Cited by 50 publications

(31 citation statements)

References 5 publications

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“…The mean monthly k p values for the 2-years study period using the Eqs.3 up to 9 are given in Table 4. Using the ASCE-PMos(h) for the estimation of the daily ET o and the statistical criteria of R 2 , RMSE and MBE (Figure 2) from the comparison analysis between the different k p equations, resulted the follow order in prediction acing [14,15], different predictive accuracy is observed among the aforementioned k p equations, which can be ascribed a) mainly to the different reference evapotranspiration method, which is used for the comparisons and b) secondly to the different climatic-environmental conditions. This indicates the necessity to validate these equations before their use.…”

Section: Evaluation Of Pan Coefficients Equationsmentioning

confidence: 99%

“…Based on literature review, the values of k p cover a range between 0.3 and 1.1, and are proportional to relative humidity and inverse proportional to wind speed [6,14,15] …”

Section: Epan and Pan Coefficient Equationsmentioning

confidence: 99%

“…The k p is obtained as a constant value adjusted to specific environmental conditions [6] or as equations [14,15]. The use of E pan measurements and k p coefficients has the advantage of the low cost equipment, while it has the disadvantage of the k p calibration and the frequent visits for the preservation of water level and clarity versus the agro-meteorological stations.…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of pan coefficient equations in a semi-arid Mediterranean environment using the ASCE-standardized Penman-Monteith method

Aschonitis¹,

Antonopoulos²,

Papamichail³

2012

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Section: Evaluation Of Pan Coefficients Equationsmentioning

confidence: 99%

“…Based on literature review, the values of k p cover a range between 0.3 and 1.1, and are proportional to relative humidity and inverse proportional to wind speed [6,14,15] …”

Section: Epan and Pan Coefficient Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of pan coefficient equations in a semi-arid Mediterranean environment using the ASCE-standardized Penman-Monteith method

Aschonitis¹,

Antonopoulos²,

Papamichail³

2012

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“…Santos et al (2008) ressaltaram que uma das limitações no uso de tanques evaporimétricos é a ocorrência de precipitações. De fato, Jensen et al (1990) observaram que, durante períodos chuvosos, *Hopkins (2000); ** Camargo & Sentelhas (1997 (Gundekar et al 2008).…”

Section: Efficiency Of Methods For Calculating Class a Pan Coefficienunclassified

Eficiência de métodos para o cálculo de coeficientes do tanque classe A na estimativa da evapotranspiração de referência

Cunha

Nascimento

Silveira

et al. 2013

Pesqui. Agropecu. Trop.

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INTRODUÇÃOO processo de ocorrência simultânea da evaporação da água do solo e da transpiração da água pela planta é denominado evapotranspiração, sendo uma ABSTRACT RESUMOparcela da água cedida à atmosfera. A evapotranspiração é o principal componente de saída do balanço hídrico, sendo um processo de grande relevância para o manejo agrícola. Para Pereira et al. (1997), a evapotranspiração é controlada, principalmente, pela Efficiency of methods for calculating class A pan coefficients to estimate evapotranspiration referenceThe class A pan coefficients (Kp) can be determined with several methods, most based on wind speed, relative humidity and conditions and extension of the border which circles the pan. This study aimed at evaluating the performance of methods used for estimating the Kp, as well as an average and constant Kp (0.70), to evaluate the reference evapotranspiration (ET 0 ) under Brazilian Savannah conditions, in Santo Antônio de Goiás, Goiás State, Brazil. The methods were assessed on an annual basis and during the dry and rainy seasons. The ET 0 resulting from the class A pan evaporation, multiplied by the Kp values estimated with the aid of the Doorenbos & Pruitt (1977), Cuenca (1989), Snyder (1992, Pereira et al. (1995) and Allen et al. (1998) methods, were compared with the ET 0 estimated by using the Penman-Montheit equation. The coefficients of determination (r 2 ), correlation (r), Willmott index of agreement (d) and performance (c), as well as the mean and maximum absolute errors, were also estimated. Considering the weather conditions during the experiment, the best Kp method to estimate the annual ET 0 was the one proposed by Pereira et al. (1995). For the dry season, the method proposed by Cuenca (1989) performed better, while, for the rainy season, all methods showed a low performance, with the Pereira et al. (1995) method being the most efficient one. The use of a constant Kp of 0.70 resulted in a good performance and showed to be a practical option, however, it is necessary to determine it where it will be applied.

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“…One method to determine the reference evapotranspiration (ET 0 [mm]) is the use of a class-A pan. Due to differences in albedo between water and grass and island effects, among other factors, these measured data have to be corrected by a so-called pan coefficient (Irmark et al, 2002;Gundekar et al, 2008), which is location dependent (Howell et al, 1983). Actual evapotranspiration is even more difficult to measure under field conditions.…”

Section: Introductionmentioning

confidence: 99%

Separating precipitation and evapotranspiration from noise – a new filter routine for high-resolution lysimeter data

Peters

Nehls

Schonsky

et al. 2014

Hydrol. Earth Syst. Sci.

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Abstract. Weighing lysimeters yield the most precise and realistic measures for evapotranspiration (ET) and precipitation (P ), which are of great importance for many questions regarding soil and atmospheric sciences. An increase or a decrease of the system mass (lysimeter plus seepage) indicates P or ET. These real mass changes of the lysimeter system have to be separated from measurement noise (e.g

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Evaluation of pan coefficient for reference crop evapotranspiration for semi-arid region

Cited by 50 publications

References 5 publications

Evaluation of pan coefficient equations in a semi-arid Mediterranean environment using the ASCE-standardized Penman-Monteith method

Evaluation of pan coefficient equations in a semi-arid Mediterranean environment using the ASCE-standardized Penman-Monteith method

Eficiência de métodos para o cálculo de coeficientes do tanque classe A na estimativa da evapotranspiração de referência

Separating precipitation and evapotranspiration from noise – a new filter routine for high-resolution lysimeter data

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