scholarly journals Reference evapotranspiration estimation by the Irrigameter in Southern Tocantins State, Brazil

2017 ◽  
Vol 21 (5) ◽  
pp. 293-297
Author(s):  
Luan B. Giovanelli ◽  
Rubens A. Oliveira ◽  
Jair C. Oliveira-Filho ◽  
Júlio C. M. Baptestini ◽  
Fábio T. Delazari ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Experimental Design ◽  
Crop Yield ◽  
Water Depth ◽  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Climatic Conditions ◽  
Equipment Acquisition ◽  
Evapotranspiration Estimation ◽  
Water Height

ABSTRACT The choice for the most appropriate method to estimate evapotranspiration depends on the availability of meteorological data, required level of precision and cost of equipment acquisition. For this estimate, the Irrigameter is simple to operate, precise and economically viable to farmers. In addition, it collaborates in the application of the necessary water depth to crops, thus avoiding unnecessary energy consumption, environmental degradation, and increasing crop yield and improving crop quality. In this context, the objective of this research was to estimate the reference evapotranspiration using the Irrigameter, for the climatic conditions of the Southern Tocantins state, Brazil. The experimental design was completely randomized with Irrigameters operating with seven water heights in the evaporator, as treatments, with three replicates. The reference evapotranspiration was obtained by FAO-56 Penman-Monteith method. For the analyzed climatic conditions, the water height in the evaporator recommended to estimate the reference evaporation in the spring is 3.4 cm; summer, 4.0 cm; fall, 3.8 cm; and winter, 2.3 cm.

scholarly journals Empirical methods for reference evapotranspiration estimation

2020 ◽  
Vol 19 (3) ◽  
pp. 203-210
Author(s):  
Oswaldo Palma Lopes Sobrinho ◽  
Wady Lima Castro Júnior ◽  
Leonardo Nazário Silva dos Santos ◽  
Gerlange Soares da Silva ◽  
Álvaro Itaúna Schalcher Pereira ◽  
...  
Keyword(s):  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Physical Phenomenon ◽  
Climatic Conditions ◽  
Alternative Methods ◽  
Empirical Methods ◽  
Class A ◽  
Evapotranspiration Estimation ◽  
Almost All ◽  
Meteorological Elements

The reference evapotranspiration (ETo) is a parameter applied in meteorological, climatological and hydrological studies being of great importance for the planning, management and management of water resources. Due to the need for knowledge about the loss of water from vegetated surfaces, researchers have developed a variety of methods for estimating ETo, some of which are well accepted, while others are criticized, such as the Penman-Monteith-FAO (PM-FAO) meteorological data, which is not always available by limiting its use. The PM-FAO method has been used for decades to be considered internationally and most appropriate for ETo estimates. This method represents the physical phenomenon of evapotranspiration that involves almost all meteorological elements analyzed in automatic and conventional meteorological stations. On the other hand, when this method is impossible to apply due to the lack of some input data, alternative methods are justified (Hargreaves-Samani, Blaney-Criddle, Priestley-Taylor, Jensen-Haise, Camargo, Makkink, Kharrufa , Linacre, Class A tank, Thornthwaite and solar radiation) according to soil and climatic conditions. 

scholarly journals Performance of different methods for reference evapotranspiration estimation in Jaíba, Brazil

2018 ◽  
Vol 22 (2) ◽  
pp. 83-89 ◽  
Author(s):  
Gustavo H. da Silva ◽  
Santos H. B. Dias ◽  
Lucas B. Ferreira ◽  
Jannaylton É. O. Santos ◽  
Fernando F. da Cunha
Keyword(s):  
Wind Speed ◽  
Solar Radiation ◽  
Standard Method ◽  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Air Humidity ◽  
Method Performance ◽  
Relative Air Humidity ◽  
Evapotranspiration Estimation ◽  
Missing Variables

ABSTRACT FAO Penman-Monteith (FO-PM) is considered the standard method for the estimation of reference evapotranspiration (ET0) but requires various meteorological data, which are often not available. The objective of this work was to evaluate the performance of the FAO-PM method with limited meteorological data and other methods as alternatives to estimate ET0 in Jaíba-MG. The study used daily meteorological data from 2007 to 2016 of the National Institute of Meteorology’s station. Daily ET0 values were randomized, and 70% of these were used to determine the calibration parameters of the ET0 for the equations of each method under study. The remaining data were used to test the calibration against the standard method. Performance evaluation was based on Willmott’s index of agreement, confidence coefficient and root-mean-square error. When one meteorological variable was missing, either solar radiation, relative air humidity or wind speed, or in the simultaneous absence of wind speed and relative air humidity, the FAO-PM method showed the best performances and, therefore, was recommended for Jaíba. The FAO-PM method with two missing variables, one of them being solar radiation, showed intermediate performance. Methods that used only air temperature data are not recommended for the region.

scholarly journals Calibration of reference evapotranspiration models in Pará

2019 ◽  
Vol 42 ◽  
pp. e42475
Author(s):  
Vivian Dielly da Silva Farias ◽  
Deborah Luciany Pires Costa ◽  
Joao Vitor de Novoa Pinto ◽  
Paulo Jorge Oliveira Ponte de Souza ◽  
Everaldo Barreiro de Souza ◽  
...  
Keyword(s):  
Water Management ◽  
Linear Regression ◽  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Climatic Conditions ◽  
Estimation Methods ◽  
Correction Factors ◽  
Regression Methods ◽  
Dry Seasons ◽  
Statistical Criteria

The use of empirical agrometeorological models that can be adjusted to the climatic conditions of different regions has become increasingly necessary to improve water management in grain-producing municipalities. The aim of this work is to examine the correlation between various reference evapotranspiration (ETo) estimation methods and the standard FAO 56 Penman-Monteith method, as well as to determine correction factors, when necessary, for crop-producing municipalities in the northeast of Pará, during both the rainy and dry seasons. We compared simpler methods of ETo estimation to the FAO 56 Penman-Monteith method. For this purpose, meteorological data from Tracuateua, Bragança, Capitão Poço and Castanhal, provided by the National Institute of Meteorology (INMET), were used. The calibration of equations was performed through linear regression. The accuracy of different estimation methods was examined. The Turc, FAO 24 Blaney-Criddle and regression methods presented the best results for all statistical criteria; the Priestley-Taylor, Makkink and FAO 24 Radiation methods presented excellent results after calibration. The methods of Camargo and Hargreaves-Samani produced the worst results for all the criteria.

scholarly journals FUNÇÃO DE PRODUÇÃO DA CULTURA DO MELÃO PARA NÍVEIS DE ÁGUA E ADUBAÇÃO NITROGENADA NO VALE DO CURU-CE

Irriga ◽  
2002 ◽  
Vol 7 (2) ◽  
pp. 98-105 ◽  
Author(s):  
Viviane Da Silva Barros ◽  
Raimundo Nonato Távora Costa ◽  
José Vanglésio de Aguiar
Keyword(s):  
Experimental Design ◽  
Crop Yield ◽  
Water Depth ◽  
Deep Water ◽  
Irrigation Water ◽  
Nitrogen Fertilization ◽  
Water Levels ◽  
Experimental Station ◽  
Maximum Economic Yield ◽  
Fertilization Effect

FUNÇÃO DE PRODUÇÃO DA CULTURA DO MELÃO PARA NÍVEIS DE ÁGUA E ADUBAÇÃO NITROGENADA NO VALE DO CURU-CE  Viviane da Silva BarrosRaimundo Nonato Távora CostaJosé Vanglésio de AguiarDepartamento de Engenharia Agrícola,Universidade Federal do Ceará, Campus do Pici, Bloco 804,CEP 60455-760, Fortaleza – CE.   1 RESUMO  Na presente pesquisa avaliaram-se os efeitos dos níveis de água, da adubação nitrogenada e da interação destes fatores sobre o rendimento econômico da cultura do melão, variedade AF-682. O experimento foi conduzido na área irrigada da Fazenda Experimental Vale do Curu, Pentecoste - CE, no período de agosto a dezembro de 1998. O delineamento experimental  foi em blocos completos ao acaso com parcelas subdivididas e quatro repetições. Os tratamentos consistiram da combinação de  seis  lâminas de irrigação (233,8, 221,4, 204,4, 183,5, 158,9 e 132,2mm) e quatro doses de nitrogênio (0, 75, 150 e 300 kg.ha-1). A aplicação de água foi realizada através de um sistema de irrigação por sulcos retos e abertos ao final. As irrigações foram controladas por tensiômetros, utilizando-se um potencial mátrico crítico e indicativo de quando irrigar, equivalente a –30kPa.  O rendimento máximo de 30574 kg.ha-1 foi obtido com uma lâmina total de água de 222,4mm e uma dose de nitrogênio de 209,2kg.ha-1. Constatou-se não apresentar vantagem econômica a substituição do fator lâminas de água pelo fator doses de nitrogênio. Nas parcelas que receberam o maior nível de adubação nitrogenada (300kg.ha-1),  a eficiência de uso da água decresceu com o aumento da lâmina total de água.  Quanto à eficiência ótima econômica do uso de água, de 13,77 kg.m-3 ou 137,7 kg.ha-1.mm-1, correspondeu a uma adubação nitrogenada de 195,24 kg.ha-1.  UNITERMOS: irrigação por sulcos, adubação nitrogenada, rendimento.   BARROS, V.S., COSTA, R. N. T., AGUIAR, J. V.  IRRIGATION AND NITROGEN FERTILIZATION EFFECT ON MELON CROP YIELD   2 ABSTRACT  This experiment aimed to determine the irrigation and nitrogen fertilization effect on melon crop  yield. This experiment was carried out  from August to  December 1998 in  Curu Valley Experimental Station at Pentecoste-CE. The experimental design was split plot randomized blocks and treatments consisted of six irrigation water levels (233.8, 221.4, 204.4, 183.5, 158.9 e 132.2mm) and four nitrogen fertilization levels (0, 75, 150 e 300 kg.ha-1). The crop was irrigated by tensiometer monitoring set at 0.15 m deep. Water was applied every time the tensiometers reached –30 kPa. Maximum economic yield (30574 kg.ha-1) was obtained through  the production function using 222.4 mm of water and 209.2 kg ha-1 of nitrogen. It could be concluded that there has been no advantage on the water depth substitution for nitrogen fertilization The optimum economical water using was 13.8 kg.m3 or 138 kg.ha-1.mm-1, corresponding to 195.2 kg.ha-1 of nitrogen.  KEYWORDS: furrow irrigation, nitrogen fertilization, yield.

scholarly journals Global comparison of 20 reference evapotranspiration equations in a semi-arid region of Iran

2018 ◽  
Vol 50 (1) ◽  
pp. 282-300 ◽  
Author(s):  
Hadi Farzanpour ◽  
Jalal Shiri ◽  
Ali Ashraf Sadraddini ◽  
Slavisa Trajkovic
Keyword(s):  
Arid Region ◽  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Irrigation Scheduling ◽  
Climatic Conditions ◽  
Accurate Estimation ◽  
Management Scenarios ◽  
Global Comparison ◽  
Semi Arid Region ◽  
Semi Arid

Abstract Accurate estimation of reference evapotranspiration (ETo) is a major task in hydrology, water resources management, irrigation scheduling and determining crop water requirement. There are many empirical equations suggested by numerous references in literature for calculating ETo using meteorological data. Some such equations have been developed for specific climatic conditions while some have been applied universally. The potential for usage of these equations depends on the availability of necessary meteorological parameters for calculating ETo in different climate conditions. The focus of the present study was a global cross-comparison of 20 ETo estimation equations using daily meteorological records of 10 weather stations (covering a period of 12 years) in a semi-arid region of Iran. Two data management scenarios, namely local and cross-station scenarios, were adopted for calibrating the applied equations against the standard FAO56-PM model. The obtained results revealed that the cross-station calibration might be a good alternative for local calibration of the ETo models when proper similar stations are used for feeding the calibration matrix.

scholarly journals ESTUDO COMPARATIVO ENTRE METODOLOGIAS DE ESTIMATIVA DA EVAPOTRANSPIRAÇÃO DE REFERÊNCIA PARA LOCALIDADES DO NORTE DE MINAS GERAIS

Irriga ◽  
2022 ◽  
Vol 1 (4) ◽  
pp. 714-721
Author(s):  
Lucas da Costa Santos ◽  
Lucas Santos do Patrocínio Figueiró ◽  
Alex Xavier Ribeiro Andrade ◽  
Antônio Costa Ferreira Neto ◽  
Caroline Salezzi Bonfá
Keyword(s):  
Meteorological Data ◽  
Irrigation Management ◽  
Absolute Error ◽  
Minas Gerais ◽  
Climatic Conditions ◽  
Empirical Methods ◽  
The North ◽  
And Performance ◽  
Evapotranspiration Estimation ◽  
E Mail

ESTUDO COMPARATIVO ENTRE METODOLOGIAS DE ESTIMATIVA DA EVAPOTRANSPIRAÇÃO DE REFERÊNCIA PARA LOCALIDADES DO NORTE DE MINAS GERAIS     LUCAS DA COSTA SANTOS1; LUCAS SANTOS DO PATROCÍNIO FIGUEIRÓ1; ALEX XAVIER RIBEIRO DE ANDRADE1; ANTÔNIO COSTA FERREIRA NETO1 E CAROLINE SALEZZI BONFÁ1   1 Departamento de Agronomia, Universidade Federal dos Vales do Jequitinhonha e Mucuri – UFVJM, Campus JK, Rodovia MGT 367-KM 583, nº 5000, Alto da Jacuba. CEP: 39.100-000, Diamantina, Minas Gerais, Brasil. E-mail: [email protected];[email protected];[email protected]; [email protected]; [email protected].     1 RESUMO   A determinação da evapotranspiração é imprescindível para a prática racional da irrigação, o que tem conduzido à formulação de diversas equações para estimativa desta importante variável meteorológica. Nesse sentido, faz-se necessário estudos comparativos com estas equações de modo a avaliar, localmente, sua aplicabilidade. Em linha com o exposto, objetivou-se comparar, para as condições climáticas de Salinas e Januária (ambos situados no Norte de Minas Gerais, Brasil), métodos empíricos de estimativa da evapotranspiração com o método padrão de Penman-Monteith (FAO56). Para tanto, utilizou-se dados meteorológicos de cinco anos (2016 a 2020) obtidos do Instituto Nacional de Meteorologia (INMET). Para a análise comparativa foram utilizados os seguintes indicadores estatísticos: coeficientes de determinação (R²) e correlação (r), erro absoluto médio (EAM), raiz do erro quadrado médio (REQM), índice de concordância (d) e índice de desempenho (c). Os resultados obtidos demonstram que, para as duas localidades avaliadas, o método de Blaney-Criddle apresenta o melhor desempenho para a estimativa da evapotranspiração, por outro lado, as equações de Hargreaves-Samani e Priestley-Taylor exibiram performance insatisfatória.   Palavras-chave: métodos empíricos, demanda hídrica de cultivos, manejo da irrigação.     SANTOS, L. C.; FIGUEIRÓ, L. S. P.; ANDRADE, A. X. R.; FERREIRA NETO, A. C.; BONFÁ, C. B. COMPARATIVE STUDY BETWEEN REFERENCE EVAPOTRANSPIRATION ESTIMATION METHODOLOGIES FOR NORTHERN MINAS GERAIS LOCATIONS     2 ABSTRACT   The determination of evapotranspiration is essential for the rational practice of irrigation, which has led to the formulation of several equations to estimate this important meteorological variable. In line with the above objective was to compare, for the climatic conditions of Salinas and Januária (both located in the North of Minas Gerais, Brazil), empirical methods for estimating evapotranspiration with the standard method of Penman-Monteith (FAO56). For this purpose, meteorological data for five years (2016 to 2020) obtained from the National Institute of Meteorology (INMET) were used. For the comparative analysis, the following statistical indicators were used: coefficients of determination (R²) and correlation (r), mean absolute error (EAM), root mean square error (REQM), agreement index (d) and performance index (c). The results obtained demonstrate that, for the two locations evaluated, the Blaney-Criddle method presents the best performance for estimating evapotranspiration, on the other hand, the Hargreaves-Samani and Priestley-Taylor equations showed unsatisfactory performance.   Keywords: crop water demand, empirical methods, irrigation management.

scholarly journals HARGREAVES & SAMANI SUBESTIMA A EVAPOTRANSPIRAÇÃO DA CEBOLA NO ALTO VALE DO ITAJAÍ

Irriga ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 377-387
Author(s):  
Jaquelini Garcia ◽  
João Célio De Araújo ◽  
Francisco Olmar Gervini de Menezes Júnior
Keyword(s):  
Experimental Design ◽  
Allium Cepa ◽  
Water Depth ◽  
Reference Evapotranspiration ◽  
Santa Catarina ◽  
Dry Biomass ◽  
National Production ◽  
Number Of Leaves ◽  
E Mail ◽  
Santa Catarina State

HARGREAVES & SAMANI SUBESTIMA A EVAPOTRANSPIRAÇÃO DA CEBOLA NO ALTO VALE DO ITAJAÍ     JAQUELINI GARCIA1; JOÃO CÉLIO DE ARAÚJO2 E FRANCISCO OLMAR GERVINI DE MENEZES JÚNIOR3   1 Instituto Federal Catarinense, Campus Rio do Sul. Estrada do Redentor, 5665, Canta Galo, CEP 89163-356, Rio do Sul,SC, Brasil. E-mail: [email protected] 2 Instituto Federal Catarinense, Campus Rio do Sul. Estrada do Redentor, 5665, Canta Galo, CEP 89163-356, Rio do Sul, SC, Brasil. E-mail: [email protected]. 3Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina, Estação Experimental de Ituporanga. Estrada Geral Lageado Águas Negras, 459, Águas Negras, CEP 88400-000, Ituporanga, SC, Brasil. Email: [email protected]     1 RESUMO   A cultura da cebola é amplamente difundida na região do Alto Vale do Itajaí, SC, que desempenha papel de destaque na produção nacional. Esta pesquisa teve por objetivo avaliar a eficiência da equação Hargreaves & Samani (HS) na estimativa da evapotranspiração da cultura da cebola produzida na região do Alto Vale do Itajaí, SC. O experimento foi conduzido em ambiente protegido utilizando o cultivar Bola Precoce. Para a estimativa da lâmina de água a ser aplicada, utilizou-se da equação de determinação da evapotranspiração de referência de HS. Os tratamentos consistiram em: lâmina calculada por HS, 70% da lâmina calculada por HS, 130% da lâmina calculada por HS e precipitação local. O delineamento experimental foi de blocos ao acaso. Avaliou-se o número de folhas, diâmetro de pseudocaule, diâmetro, classificação e estimativa de produtividade dos bulbos, biomassa fresca/seca dos bulbos, além da biomassa seca da parte aérea. A lâmina de água baseada em 130% da equação apresentou bulbos com maior diâmetro, biomassa fresca/seca, maior percentual de bulbos classe 3 e maior estimativa de produtividade. Conclui-se que a equação de HS subestima a evapotranspiração da cultura e requer ajustes para ser utilizada na região do Alto Vale do Itajaí, SC.   Palavras-chave: Allium cepa, ETo, irrigação, produtividade.     GARCIA, J.; ARAÚJO, J. C. de; MENEZES JÚNIOR, F. O. G. de. HARGREAVES & SAMANI UNDERSTATES THE EVAPOTRANSPIRATION OF ONION IN THE UPPER VALLEY OF ITAJAÍ     2 ABSTRACT   The onion crop is widespread in Itajaí Upper Valley region,  SC, which plays a prominent role in national production. This research aimed to evaluate the efficiency of the Hargreaves & Samani (HS) equation in estimating the evapotranspiration of the onion crop produced in Itajaí Upper Valley region, Santa Catarina State. The experiment was conducted in a greenhouse using the cultivar Bola Precoce. To estimate the water depth to be applied, the reference evapotranspiration HS equation was used. The treatments consisted of: depth calculated by HS, 70% of depth calculated by HS, 130% of depth calculated by HS and local precipitation. The experimental design was randomized blocks. The number of leaves, pseudostem diameter, classification and estimate of bulb productivity, fresh / dry biomass of the bulbs, in addition to the dry biomass of the shoot were evaluated. The water depth based on 130% of the equation showed bulbs with larger diameter, fresh / dry biomass, higher percentage of class 3 bulbs and higher estimate of productivity. Therefore, the HS equation underestimates the evapotranspiration for Itajaí Upper Valley region, SC, requiring adjustments for use.   Keywords: Allium cepa, ETo, irrigation, productivity.

scholarly journals Optimal Selection of Empirical Reference Evapotranspiration Method in 36 Different Agricultural Zones of China

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 31
Author(s):  
Yong Yang ◽  
Rensheng Chen ◽  
Chuntan Han ◽  
Zhangwen Liu ◽  
Xiqiang Wang
Keyword(s):  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Aridity Index ◽  
Empirical Method ◽  
Climatic Conditions ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Temperature Method ◽  
The Relationship ◽  
Selection Of

The Food and Agriculture Organization has proposed the current version of the Penman–Monteith method (FAO56-PM) as the standard for calculating reference evapotranspiration (ET0); however, high meteorological data requirements limit its application in many areas. There is thus an urgent need to identify the best alternative empirical method to accurately calculate ET0 in regions that lack sufficient meteorological data. In this study, three temperature-based methods and five radiation-based methods were evaluated using ET0 values generated using the FAO56-PM method in 36 agricultural zones in China based on meteorological data from 823 stations, measured between 2011 and 2020. The results showed that the optimal temperature-based method and radiation-based method differed for different agricultural zones, and no one temperature method or radiation method could be suitable for all agricultural zones. The eight empirical methods were regionally calibrated to improve the ET0 calculation accuracy in the different zones. The relationship between the optimal methods and climatic conditions showed that the most reliable empirical method could be selected according to the local annual mean temperature and aridity index. The results provide useful guidance for the selection of reliable empirical ET0 methods in agricultural zones outside China.

scholarly journals How Climate Change Affects the Building Energy Consumptions Due to Cooling, Heating, and Electricity Demands of Italian Residential Sector

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 410 ◽  
Author(s):  
Francesco Mancini ◽  
Gianluigi Lo Basso
Keyword(s):  
Climate Change ◽  
Energy Consumption ◽  
Climate Adaptation ◽  
Meteorological Data ◽  
Critical Role ◽  
Climatic Conditions ◽  
Slight Reduction ◽  
Air Conditioners ◽  
Residential Sector ◽  
Heating And Cooling

Climate change affects the buildings’ performance, significantly influencing energy consumption, as well as the indoor thermal comfort. As a consequence, the growing outdoor environmental temperatures entail a slight reduction in heating consumption and an increase in cooling consumption, with different overall effects depending on the latitudes. This document focuses attention on the Italian residential sector, considering the current and reduced meteorological data, in anticipation of future climate scenarios. According to a sample of 419 buildings, referring to the climatic conditions of Milan, Florence, Rome, and Naples, the heating and cooling needs are calculated by a simplified dynamic model, in current and future conditions. The effects of the simplest climate adaptation measure, represented by the introduction of new air conditioners, have been also evaluated. The simulations results show an important reduction in complex energy consumption (Milan −6%, Florence −22%, Rome −25%, Naples −30%), due to the greater incidence of heating demand in the Italian context. However, the increase in air conditioning electrical consumption over the hot season (Milan +11%, Florence +20%, Rome +19%, Naples +16%) can play a critical role for the electrical system; for that reason, the introduction of photovoltaic arrays as a compensatory measure have been analysed.

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