DISTRIBUIÇÃO DA EVAPORAÇÃO EM ESTUFA PLÁSTICA NA PRIMAVERA

Irriga ◽  
2001 ◽  
Vol 6 (3) ◽  
pp. 120-127
Author(s):  
Reginaldo Ferreira Santos ◽  
Antonio Evaldo Klar
Keyword(s):  
Spatial Variability ◽  
Pan Evaporation ◽  
Spring Season ◽  
Class A ◽  
Agricultural Sciences ◽  
E Mail ◽  
Center Area ◽  
Class A Pan

DISTRIBUIÇÃO DA EVAPORAÇÃO EM ESTUFA PLÁSTICA NA PRIMAVERA  Reginaldo Ferreira SantosCentro de Ciências Exatas e Tecnológica da UNIOESTE- CP 711CEP 858114-110, Cascavel, PR - Fone: 0XX45 2203155.  E-mail: [email protected] Evaldo KlarDepartamento de Engenharia Rural - Faculdade de Ciências Agronômica- UNESP - CEP 18603-970 - Botucatu, SP. CP: 237.  E-mail:  [email protected]  1  RESUMO O presente trabalho teve como objetivo avaliar a distribuição da evaporação no interior de uma estufa plástica, com uma cultura de pimentão, através da variabilidade espacial e comparar a evaporação dos microevaporímetros com os valores do Tanque classe "A". O experimento foi conduzido no Campus da Universidade Estadual Paulista - FCA/UNESP, no período de primavera, em estufa plástica de polietileno de baixa densidade (PEBD). Na distribuição da evaporação em estufa com orientação norte/sul, verificou-se que as maiores evaporações ocorreram nas extremidades sul e norte tendente ao lado oeste. Já as menores evaporações localizaram-se no centro. No período de primavera, a evaporação média nos microevaporímetros superestimou em 55% a evaporação determinada no Tanque classe "A". UNITERMOS: evaporação, geoestatística, estufa.  SANTOS, R.F, KLAR, A.E.  EVAPORATION DISTRIBUTION INSIDE A PLASTIC TUNNEL IN THE SPRING SEASON  2  ABSTRACT                 The main aim of this study was to verify the evaporation distribution inside a plastic tunnel, with pepper crop, oriented to north/south, through spatial variability and to compare Class A Pan evaporation to punctual evaporations of 40 equidistant microevaporimeters placed from 50cm the soil. The study was carried out at the College of Agricultural Sciences/UNESP, Botucatu – SP in the spring season.  The highest evaporation occurred next to north and to south sides of the tunnel, with tendency to west. Consequently, the lowest evaporations occurred at the center area. The microevaporimeter evaporations were 55% higher than those obtained from Class A Pan. KEYWORDS: evaporation distribution, microevaporimeter.

scholarly journals Annual Actual Evapotranspiration Estimation via GIS Models of Three Empirical Methods Employing Remotely Sensed Data for the Peloponnese, Greece, and Comparison with Annual MODIS ET and Pan Evaporation Measurements

2021 ◽  
Vol 10 (8) ◽  
pp. 522
Author(s):  
Stavroula Dimitriadou ◽  
Konstantinos G. Nikolakopoulos
Keyword(s):  
Time Scale ◽  
Gradual Decrease ◽  
Actual Evapotranspiration ◽  
Pan Evaporation ◽  
Empirical Methods ◽  
Remotely Sensed Data ◽  
Upward Trend ◽  
Class A ◽  
Evapotranspiration Estimation ◽  
Class A Pan

Actual evapotranspiration (ETa) has been insufficiently investigated in Greece. This study aimed to estimate annual ETa by empirical methods (Turc, modified Turc, and Coutagne) for the Peloponnese, Greece, a Mediterranean testbed, between 2016–2019, four of the warmest years since the preindustrial era, and compare them to MODIS ET. Furthermore, measurements of annual pan evaporation (Epan) were performed for two Class A pan stations in the Peloponnese with different reliefs and conditions. The empirical methods and statistical formulae (RMSD, MB, and NMB) were developed as models in ArcMap. The outcomes of the Turc method resembled MODIS ET ranges for all years, followed by those of Coutagne. The estimates by the modified Turc method were almost identical to MODIS ET. Therefore, the modified Turc method can be used as an alternative to MODIS ET (and vice versa) for the Peloponnese for 2016–2019. Moreover, the Epan at Patras University station (semiurban, low elevation) exhibited an upward trend resembling the trends of the empirical methods over the study years, whereas the Epan at Ladonas station (higher elevation, lakeside) required investigation on a monthly time scale. Additionally, the gradual decrease of pan-water icing at Ladonas in December (from 20 d in 2016 to 0 d in 2019) could imply an undergoing decrease in snowpack storage retention across the mountains of the Peloponnese.

scholarly journals Measurement and Estimation of Annual Variability of Water Loss at Njuwa Lake Using Class ‘A’ Pan Evaporation Method

2020 ◽  
pp. 11-21
Author(s):  
A. A. Sadiq
Keyword(s):  
Water Loss ◽  
Irrigation Scheduling ◽  
Water Volume ◽  
Pan Evaporation ◽  
Morphometric Characteristics ◽  
Average Width ◽  
Evaporation Method ◽  
Class A ◽  
Annual Variability ◽  
Class A Pan

Aim: To measure and estimate the annual variability of water loss at Njuwa Lake using Class ‘A’ Pan Evaporation Method. Place and Duration of Study: Njuwa Lake in Yola South LGA, Adamawa State Nigeria between November, 2019 and May, 2020. Methodology: Direct measurements of morphometric characteristics of the lake were adopted using simple bathymetric method. Evaporation rates data and other related weather variable for the periods of ten (2007-2016) years were obtained from Upper Benue River Basin Development Authority located near the lake where the volume of water in the lake and the annual water loss were estimated using FAO estimate of water requirement procedures. Results: The results revealed that Njuwa Lake has morphometric characteristics of 1, 325 m average length, 180m average width, average depth 3.4 m, 238, 500 m2 of  surface area, 1,445 m shoreline length and 0.834 m shoreline development with an estimated water volume of  810, 900 m3 respectively. Similarly, highest Class ‘A’ Pan evaporation rates were found in the year 2011, 2007 and 2008 with the corresponding total annual values of 2688.06 mm, 2403.64 mm and 2389.63 mm having an estimated values of water lost from the lake of 641, 102.310 m3 (79.07%), 573, 268.140 m3(70.7%) and 569, 926.755 m3 (70.29 %) correspondingly. Conversely, the year 2013,2012 and 2014 were found with the lowest measured Pan evaporation rates (1585.00 mm, 1611.54 mm and 1663.27 mm) with an estimated water lost on the lake of about  378, 022.500 m3 (46.6 %), 384, 352.290 m3 (47.4 %) and 396, 689.895 m3 (48.9 %). Conclusion: The rate of water loss was through evaporation was estimated to be greater than the stored water in the Lake in most of the years under study which led to untimely drying of the lake thereby affecting the irrigation farming in the area. Valuable strategies of water use efficiency and irrigation scheduling for effective utilization of the limited stored water in the lake for sustainable food production should be therefore adopted. The research work, however, need further work to make a comparison between the class ‘A’ Pan method and other empirical models method to revalidate the reliability.

scholarly journals Yield, Growth, and Mineral Nutrition of Young `Ray Ruby' Grapefruit Trees under Trickle or Flood Irrigation and Various Nitrogen Rates

1992 ◽  
Vol 117 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Dariusz Swietlik
Keyword(s):  
Mineral Nutrition ◽  
Soil Depth ◽  
Fruit Size ◽  
Growth Yield ◽  
N Fertilization ◽  
Citrus Paradisi ◽  
Pan Evaporation ◽  
Class A ◽  
Size Growth ◽  
Class A Pan

Growth, fruiting, and mineral nutrition of trickle- or flood-irrigated young `Ray Ruby' grapefruit (Citrus paradisi Macf.) trees on sour orange (C. aurantium L.) rootstock were compared in a 4-year field study. Trickle irrigations (two emitters per tree) were scheduled based on: 1) 0.7 (first 3 years) or 0.5 (4th year) of Class A pan evaporation (TPAN) adjusted to the ground area covered by tree canopies, or 2) tensiometer readings (TTEN) of - 0.02 MPa at 30-cm soil depth. The flood irrigations (FLOOD) were scheduled at 50% available soil water depletion at 30 cm (first 3 years) or 30- and 60-cm soil depth (the 4th year). Nitrogen at NO (none), N1(20, 40, 80, 160 g N/tree per year in the four consecutive years), or N2(twice the amount of NJ was injected into the trickle lines from January to August or, under FLOOD, split into January and May soil applications. TPAN and TTEN trees were irrigated with <10% of the water amount applied to FLOOD trees without negatively affecting tree growth, yield, or fruit size. Growth of the trees was not affected by N fertilization, but fruit count and yield and leaf N concentration were increased by the N1 and N2 treatments in the fourth growing season. Frequent N fertigations under the trickle system provided no benefits over two split-soil broadcast applications under the flood system. Fruit size was reduced by the N2 treatment. Based on the water amounts applied to TTEN trees, irrigation needs under the trickle system were estimated to be 0.75, 0.57, 0.30, and 0.20 of Class A pan evaporation adjusted to the ground area covered by the plant canopies, in the first, 2nd, 3rd, and 4th year of orchard life. The decreasing pan coefficient indicated increasing extraction of water from outside the irrigated zones. Roots of TPAN and TTEN trees grew at least 210 cm past the wetted zones into the row middles. More than half of the roots in the TPAN and TTEN treatments were found at 60- to 230-cm soil depth compared to only 17% in the FLOOD treatment.

scholarly journals DISTRIBUIÇÃO DA EVAPORAÇÃO NO INTERIOR DE UM AMBIENTE PROTEGIDO.

Irriga ◽  
2006 ◽  
Vol 11 (2) ◽  
pp. 246-256
Author(s):  
Cleber Junior Jadoski ◽  
Antonio Evaldo Klar ◽  
Marcio Furlan Maggi ◽  
Juliana Ramiro Alexandre Barreto Almeida dos Santos ◽  
Samuel Rodrigues Fulan
Keyword(s):  
Energy Distribution ◽  
Spatial Variability ◽  
Soil Surface ◽  
Longitudinal Axis ◽  
Class A ◽  
Set Up ◽  
Equidistant Points ◽  
Class A Pan

DISTRIBUIÇÃO DA EVAPORAÇÃO NO INTERIOR DE UM AMBIENTE PROTEGIDO.  Cleber Junior Jadoski1; Antonio Evaldo Klar1; Marcio Furlan Maggi2; Juliana Ramiro1 Alexandre Barreto Almeida  dos Santos1;  Samuel Rodrigues Fulan11Departamento de Engenharia Rural, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, SP,  [email protected]  2Universidade Estadual do Centro Oeste, UNICENTRO, Guarapuava, PR   1 RESUMO. Este trabalho teve por objetivo estudar a distribuição da evaporação no interior de um ambiente protegido. O experimento foi instalado em uma estufa de polietileno na Fazenda Experimental Lageado da Faculdade de Ciências Agronômicas (FCA), no período do inverno de 2005. Para analisar a distribuição espacial da energia, foram utilizados microevaporímetros plásticos de 500 ml (13,7 cmde diâmetro) com o que foram obtidos os valores respectivos de evaporação que integram os elementos meteorológicos envolvidos. Foram instalados 132 microevaporímetros distribuídos em três alturas, 0,40, 0,80 e1,20 m, a partir da superfície do solo, perfazendo 44 pontos uniformemente distribuídos. A estufa plástica é do tipo túnel com 7,5m de largura por 27,5m de comprimento, 3,20m de altura no centro e 2,00m nas paredes laterais fechadas com tela do tipo “sombrite”. A orientação noroeste/sudeste, com base no norte verdadeiro, foi adotada para o eixo longitudinal da estufa. Para a comparação das variáveis, foram utilizados princípios de geoestatística com auxílio do programa GS+. Os dados obtidos permitiram chegar às seguintes conclusões: ocorreu variabilidade espacial nas diferentes regiões e alturas de instalação dos microevaporímetros, com maior evaporação na altura mais próxima do solo no mês de julho; o tanque Classe “A” não difere significativamente em relação aos microevaporímetros; pode-se estimar a evaporação interna do ambiente protegido através de medições em um tanque Classe “A” instalado fora do ambiente protegido. UNITERMOS: Geoestatística, microevaporímetro, tanque Classe “A”,  Jadoski, c. j.; KLAR, A. E.; MAGGI, M. F.; RAMIRO, J.; Santos,  a. b. a. dos;  Fulan S. R. EVAPORATION DISTRIBUTION IN A PROTECTED ENVIRONMENT  2 ABSTRACT             This work aimed to study evaporation distribution in a protected environment.  The experiment was set up in polyethylene greenhouse at the Lageado Experimental Farm in theSchoolofAgronomic Sciences(FCA, UNESP-Botucatu) in the  winter of  2005. 132  500-ml plastic micro evaporimeters  (13.7 diameter) were used used to obtain evaporation values and analyze spatial energy distribution. These micro evaporimeters were distributed in 44 equidistant points, at three different heights from the soil surface: 0.40, 0.80 and 1.20cm The tunnel-type greenhouse was7.5 mwide,27.5 mlong and  3.20 mhigh at the center, and was covered with black shadow screen (sombrite) on the sides.  Southeast /northwest orientation, based on true north, was used foro othe greenhouse longitudinal axis.  For variable comparison,  a geostatistics  was used through the  GS+ program. From obtained data, it was concluded that: there was spatial variability at different points and heights of the microevaporimeters and higher evaporation values for the height near to  soil surface in July; evaporation values   obtained from micro evaporimeters were not statistically different from those obtained from Class “A” Pan installed in the center of  the greenhouse; the Class “A” Pan installed outside the greenhouse can be used to evaluate the internal evaporation. KEYWORDS: Geostatistics, microevaporimeter, Class “A” Pan.. 

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