Calibration of the Hargreaves–Samani method for the calculation of reference evapotranspiration in different Köppen climate classes

The Penman–Monteith equation (FAO-56) is accepted as the standard model for estimating reference evapotranspiration (ETo). However, the major obstacle to using FAO-56 widely is that it requires numerous climatic data. The Hargreaves–Samani (HS) method is frequently used for the calculation of ETo since it is based on measurements of daily minimum and maximum air temperature alone. Those are commonly recorded at many meteorological stations throughout the world. It is the objective of this paper to evaluate the quality of HS and calibrate the coefficients of this method for different climates as represented by the Köppen classification. Estimated values are compared with Penman–Monteith ETo values in terms of the coefficient of efficiency Ceff as well as the root mean square error, the mean absolute error and the Bayes information criterion. The Penman–Monteith equation for ETo (FAO-56) is based on physics and known to provide best estimates of ETo. The results of our work show that the correlation between long-term monthly means of HS and FAO-56 can be improved significantly by introducing climate-class specific coefficients.

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Assessing of evapotranspiration models using limited climatic data in Southeast Anatolian Project Region of Turkey

PeerJ ◽

10.7717/peerj.11571 ◽

2021 ◽

Vol 9 ◽

pp. e11571

Author(s):

Yusuf Aydın

Keyword(s):

Standard Model ◽

Standard Method ◽

Reference Evapotranspiration ◽

Study Data ◽

Ease Of Use ◽

Climatic Data ◽

Climate Data ◽

The Standard Model ◽

Annual Total

Evapotranspiration carries vital importance in areas with arid and semi-arid climate properties for many issues, including the planning of irrigation water as a scarce resource, the establishment of irrigation programs and conducting project design for drainage. The empirical equations used for determining plant water consumption are classified subject to the diversity of the utilized data. The Penman–Monteith method used frequently in many parts of the world as a standard method needs more climate data. Models that yield results that are similar to those of the standard method with less climate parameters are preferred due to their ease of use and wide impact. Temperature, relative humidity and radiation data for the years 2008–2017 were utilized to analyze the usability of the Hargreaves–Samani and Turc-1961 equations with regard to the estimation of reference evapotranspiration in four provinces located in Southeastern Anatolia Region. Results obtained via models were compared in pairs by way of the standard method in order to define the performance of the models. While the best performances were obtained from the comparison with the standard method and Hargreaves–Samani value pair, the comparison of the standard model with Turc displayed the lowest performance. Based on the study data, ETo-Turc values were higher in the provinces analyzed, thus displaying a lower performance. While maximum long term annual monthly average ETo-HS value was identified as 7.6 mm at Diyarbakır in July, whereas the lowest value was determined at Kilis with 5.8 mm; the highest and lowest ETo-Turc values were obtained in the same month at Diyarbakır and Kilis with 13.3 and 10.3 mm respectively. It was calculated based on the long term average annual total ETo values that while highest ETo-HS was calculated at Diyarbakır with 1,500 mm, whereas the lowest value was calculated at Batman with 1,183 mm. The highest value for ETo-Turc was obtained at Diyarbakır with 2,365 mm while Mardin had the lowest ETo value with 1,920 mm. Accordingly, based on the ETo values calculated at both cities studies based on both models, Diyarbakır had the highest values, whereas Kilis had the lowest ETo values. According to the standard method known as PM, lowest daily ETo values were calculated in all provinces, which displayed the highest performance among the models. As a result of this study, it is possible to use the Hargreaves-Samani model instead of the standard model in the absence of reliable climatic data.

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Comparative evaluation of different reference evapotranspiration models

Journal of Applied and Natural Science ◽

10.31018/jans.v9i1.1239 ◽

2017 ◽

Vol 9 (1) ◽

pp. 609-613

Author(s):

C. K. Arya ◽

R. C. Purohit ◽

L. K. Dashora ◽

P. K. Singh ◽

Mahesh Kothari ◽

...

Keyword(s):

Water Resource Management ◽

Meteorological Parameters ◽

Reference Evapotranspiration ◽

Potential Evapotranspiration ◽

Accurate Estimation ◽

Climatic Data ◽

Pan Evaporation ◽

Alternative Method ◽

Monteith Equation

The study was carried out to select best alternative method for the estimation of reference evapotranspi-ration (ET0). Accurate estimation of potential evapotranspiration is a necessary step in water resource management. Recently, the FAO-56 version of Penman-Monteith equation has been established as a standard for calculating ref-erence evapotranspiration (ET0) which requires measurement of a number of meteorological parameters namely, air temperature, relative humidity, solar radiation, and wind speed which may not be available in most of the meteoro-logical stations. Still there are different approaches (requiring less data) which estimate ET0 closely to Penman- Monteith (P-M) method for different climatological conditions. The present study is based on analysis of long term of 13 years (2000 to 2012) climatic data to calculate monthly reference evapotranspiration for Capsicum production (September–March) and also to compare the performance of evapotranspiration equations for Jhalawar district of Rajasthan with the standard FAO-56 Penman-Monteith method on the basis of the least root mean square error (RMSE) analysis. Hargreaves method and Pan evaporation (E-Pan) method overestimated the values of ETo when compared with FAO-56 Penman-Monteith method. On the basis of lowest value of RMSE, Pan evaporation method is found best alternative method to FAO-56 Penman-Monteith method in the study area.

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Forecasting the Carsharing Service Demand Using Uni and Multivariable Models

10.21203/rs.3.rs-99113/v1 ◽

2020 ◽

Author(s):

Victor Aquiles Alencar ◽

Lucas Ribeiro Pessamilio ◽

Felipe Rooke da Silva ◽

Heder Soares Bernardino ◽

Alex Borges Vieira

Keyword(s):

Short Term Memory ◽

Meteorological Data ◽

Absolute Error ◽

Climatic Data ◽

Short Term ◽

Car Sharing ◽

Urban Centers ◽

Service Demand ◽

Boosting Algorithms

Abstract Car-sharing is an alternative to urban mobility that has been widely adopted. However, this approach is prone to several problems, such as fleet imbalance, due to the variance of the daily demand in large urban centers. In this work, we apply two time series techniques, namely, Long Short-Term Memory (LSTM) and Prophet, to infer the demand for three real car-sharing services. We also apply several state-of-the-art models on free-floating data in order to get a better understanding of what works best for this type of data. In addition to historical data, we also use climatic attributes in LSTM applications. As a result, the addition of meteorological data improved the model’s performance, especially on Evo: an average Mean Absolute Error (MAE) of approximately 61.13 travels was obtained with the demand data on Evo, while MAE equals 32.72 travels was observed when adding the climatic data, the other datasets also improved but none other improved this much. For the free-floating data test, we got the Boosting Algorithms (XGBoost, Catboost, and LightGBM) got the best performance short term, the worst one has an improvement of around 22% of MAE over the next best-ranked (Prophet). Meanwhile in the long term Prophet got the best MAE result, around 22.5% better than the second-best (LSTM).

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Evapotranspiration and crop coefficients of melon plants measured by lysimeter and estimated according to FAO 56 methodology

Engenharia Agrícola ◽

10.1590/s0100-69162013000500005 ◽

2013 ◽

Vol 33 (5) ◽

pp. 929-939 ◽

Cited By ~ 3

Author(s):

Talyana K. de Melo ◽

José F. de Medeiros ◽

José E. Sobrinho ◽

Vladimir B. Figueiredo ◽

Paulo S. de Souza

Keyword(s):

Reference Evapotranspiration ◽

Irrigation Management ◽

Climatic Conditions ◽

Climatic Data ◽

And Performance ◽

Crop Coefficients ◽

The City ◽

Adequate Management ◽

Monteith Equation ◽

Statistical Indicators

Aiming at contributing to an adequate management of water resources, this study aimed to analyze and compare evapotranspiration (ETc) and crop coefficients (Kc) of melon plants measured by a lysimeter and estimated according to the FAO 56 methodology, in the city of Mossoró, state of Rio Grande do Norte (RN), Brazil. In order to measure ETc, weighing lysimeters with an area of 2.25m² were used, with two repetitions. The Penman-Monteith equation parameterized by FAO was used to estimate the reference evapotranspiration, and crop coefficients were those recommended in FAO-56 Bulletin adjusted to local climatic conditions. The required climatic data and lysimeter measurements were collected by an automatic weather station installed at the site. The results were compared by means of statistical indicators: of precision (r), of accuracy (d), and performance (c), in daily and weekly intervals. The data estimated by the FAO 56 methodology were adjusted optimally to the values measured by the lysimeters in accordance with index "c" in the two time scales assessed, indicating the potential of the method proposed by FAO to irrigation management in the climatic conditions of Agripole Assú-Mossoró.

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INTEGRATIVE USE OF PENMAN-MONTEITH EQUATION WITH REMOTE SENSING AND GEOGRAPHICAL INFORMATION SYSTEM TECHNIQUES TO ESTIMATE EVAPOTRANSPIRATION VRIANCES IN IRAQ

IRAQI JOURNAL OF AGRICULTURAL SCIENCES ◽

10.36103/ijas.v51i2.979 ◽

2020 ◽

Vol 51 (2) ◽

pp. 530-541

Author(s):

Jawad & Abed Mohamed

Keyword(s):

Remote Sensing ◽

Information System ◽

Wind Speed ◽

Reference Evapotranspiration ◽

Geographical Information ◽

Long Period ◽

Integrative System ◽

Daily Evapotranspiration ◽

Monteith Equation

This research was aimed to construct an integrative system which is capable of accurate determining and analyzing evapotranspiration rates in Iraq for long period , Since high evapotranspiration rates and extreme shortage in precipitation are the main causes of aridity, which considered principal reason for land degradation and land desertification eventually. FAO Penman-Monteith method was adopted because it's the international standard method. In this work meteorological readings of nine stations with comprehensive covering for Iraq's area were taken for every ten years in a long-term range (31 years). The daily evapotranspiration values had been calculated, then after the annual summation value determined for the years (1987, 1997, 2007, and 2017). The use of spatial analysis schemes proved that generally eighties decade of the last century had climax (Etr) values, then ETr rates rapidly decreased in whole Iraq except some anomalies. There were two reasons for this decrement, firstly air temperature value decent which increase relative humidity. Secondly wind speed rates falling (which considered the principal cause for reference evapotranspiration rates descending in this case).

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Thinking Beyond Language: Intervention for Severe Aphasia

Perspectives on Neurophysiology and Neurogenic Speech and Language Disorders ◽

10.1044/nnsld19.1.15 ◽

2009 ◽

Vol 19 (1) ◽

pp. 15-22 ◽

Cited By ~ 3

Author(s):

Nina Simmons-Mackie

Keyword(s):

Quality Of Life ◽

Communication Training ◽

Language Intervention ◽

Specific Training ◽

Environmental Support ◽

Total Communication ◽

Communication Partners

Abstract Purpose: This article addresses several intervention approaches that aim to improve life for individuals with severe aphasia. Because severe aphasia significantly compromises language, often for the long term, recommended approaches focus on additional domains that affect quality of life. Treatments are discussed that involve increasing participation in personally relevant life situations, enhancing environmental support for communication and participation, and improving communicative confidence. Methods: Interventions that have been suggested in the aphasia literature as particularly appropriate for people with severe aphasia include training in total communication, training of communication partners, and activity specific training. Conclusion: Several intervention approaches can be implemented to enhance life with severe aphasia.

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Communication Disordered: Program Implementation in Long-Term Care

Perspectives of the ASHA Special Interest Groups ◽

10.1044/persp1.sig15.64 ◽

2016 ◽

Vol 1 (15) ◽

pp. 64-67

Author(s):

George Barnes ◽

Joseph Salemi

Keyword(s):

Program Implementation ◽

Long Term Care ◽

Family Satisfaction ◽

Regulatory Compliance ◽

Care Staff ◽

Term Care ◽

Staff Members ◽

Change Policy

The organizational structure of long-term care (LTC) facilities often removes the rehab department from the interdisciplinary work culture, inhibiting the speech-language pathologist's (SLP's) communication with the facility administration and limiting the SLP's influence when implementing clinical programs. The SLP then is unable to change policy or monitor the actions of the care staff. When the SLP asks staff members to follow protocols not yet accepted by facility policy, staff may be unable to respond due to confusing or conflicting protocol. The SLP needs to involve members of the facility administration in the policy-making process in order to create successful clinical programs. The SLP must overcome communication barriers by understanding the needs of the administration to explain how staff compliance with clinical goals improves quality of care, regulatory compliance, and patient-family satisfaction, and has the potential to enhance revenue for the facility. By taking this approach, the SLP has a greater opportunity to increase safety, independence, and quality of life for patients who otherwise may not receive access to the appropriate services.

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