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 AVALIAÇÃO DA FERTIRRIGAÇÃO POTÁSSICA NA PRODUÇÃO E QUALIDADE DA ALFACE (Lactuca sativa L.) AMERICANA EM ESTUFA

Irriga ◽  
2001 ◽  
Vol 6 (1) ◽  
pp. 1-12
Author(s):  
Leandro Manoel Alves de Sousa ◽  
Hélio Grassi Filho
Keyword(s):  
Lactuca Sativa ◽  
Drip Irrigation ◽  
Water Volume ◽  
Pan Evaporation ◽  
Class A ◽  
Lactuca Sativa L ◽  
Significant Difference ◽  
Culture Development ◽  
Class A Pan

AVALIAÇÃO DA FERTIRRIGAÇÃO POTÁSSICA NA PRODUÇÃO E QUALIDADE DA ALFACE (Lactuca sativa L.) AMERICANA EM ESTUFA  Leandro Manoel Alves de SousaDep. de Eng. Rural- Faculdade de Ciências Agronômicas -UNESP -  Botucatu - SPFone: (14) 6820 - 7165 - Fax: (14) 6820 - 7194  CEP: 18603-970 [email protected]élio Grassi FilhoDep. de Recursos Naturais Área de Ciência do Solo - Faculdade de Ciências Agronômicas -UNESP - Botucatu - SP  Fone: (14) 6820 - 7100   CEP: [email protected]  1 RESUMO O ensaio foi  realizado na área experimental do Departamento de Engenharia Rural FCA/UNESP, Campus de Botucatu - SP, Brasil, no período de junho à agosto, e teve por objetivo avaliar níveis de adubação potássica em cobertura, aplicadas via água de irrigação (fertirrigação), na cultura da alface tipo americana. Utilizou-se uma estufa de arcos com 192 m2 e altura de 4,0 m, onde foram instaladas 24 parcelas (6 tratamentos x 4 repetições) de 3,0 x 1,10 m, nas quais foram transplantadas as mudas de alface com espaçamento de 0,30 m  entre plantas e que receberam os seguintes tratamentos: K0-sem potássio, K30-com 30kg ha-1 de K2O, K60-com 60kg ha-1 de K2O, K90-com 90kg ha-1 de K2O, K120-com 120kg ha-1 de K2O, e Padrão do produtor, que teve os mesmos níveis de adubação de cobertura, usada por produtores da região de Lavras - MG (200 kg de K2O + 70 kg de CaO).  Os tratamentos receberam dosagens fixas de 90kg ha-1 de N e foram divididos em 4 aplicações de cobertura (8, 18, 26 e 34 dias, após o transplante).  O sistema de irrigação utilizado foi por gotejamento e o manejo foi realizado  em função de tensiômetros com turno de rega variado, o qual foi comparado com o método de tanque Classe A para 100% da evaporação do tanque.O experimento mostrou que a aplicação de doses crescentes de potássio (0, 30, 60, 90 e 120 kg ha-1) via fertirrigação não proporcionaram diferença significativa e nem correlação entre elas, para a produção e qualidade da alface americana.  O manejo da fertirrigação proposto pelos produtores não diferenciou dos demais tratamentos. O uso de tensiômetros no monitoramento da umidade do solo, mostrou-se mais eficiente do que o método do tanque Classe A, para 100% da evaporação, alcançando uma economia de 54% do volume de água utilizado, sem afetar o desenvolvimento da cultura.  UNITERMOS: fertirrigação, potássio, alface, estufa, irrigação localizada  SOUSA, L. M. A. de,  GRASSI FILHO, H.  EVALUATION OF POTASSIUM FERTIGATION ON THE PRODUCTION AND QUALITY OF CRESPHEAD LETTUCE (Lactuca sativa L.) IN GREENHOUSE  2 ABSTRACT The present work was accomplished at the experimental area of the Department of Rural Engineering FCA/UNESP, Botucatu - SP, Brazil, and the objective was to evaluate levels of potassium fertilizer in covering, applied by irrigation water (fertigation), in cresphead lettuce.A greenhouse of metallic arches was used with 4,0 m tall and 192 m2 of area, where 24 portions were installed (6 treatments x 4 repetitions) of 3,0 x 1,10 m, in which the lettuce seedlings were transplanted with spacing of 0,30 m between plants and that received the following treatments: K0 (without potassium), K30 (using 30kg ha-1 of K2O), K60 (using 60kg ha-1 of K2O), K90 (using 90kg ha-1 of K2O), K120 (using 120kg ha-1 of K2O), and T-control, with the same levels of covering fertilizer, used for farmers of Lavras - MG (200 kg of K2O + 70 kg of CaO).The treatments received fixed levels of 90kg ha-1 of N and that were divided in 4 covering applications (8, 18, 26 and 34 days, after the transplant). The system used was drip irrigation and the setting of the quantity of water to be applied was made through the tensiometers, which was compared with the 100% Class A Pan evaporation method.The experiment verified that the application of growing doses of potassium (0, 30, 60, 90 and 120 kg ha-1) by fertigation, didn't provide significant difference  nor correlation between them, for the production and quality of the cresphead lettuce. The handling of the fertigation proposed by the farmers  didn't differentiate of the other treatments.The tensiometers use in the monitoring of the humidity of the soil, has shown more efficient than the 100% Class A Pan evaporation method, reaching an economy of 54% of the water volume used, without affecting the culture development.   KEYWORDS: fertigation, potassium, lettuce, plastic tunnel, drip irrigation

scholarly journals Effects of Irrigation on Sweetpotato Yields

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 606b-606
Author(s):  
Eric Simonne ◽  
James Bannon ◽  
Marvin Ruf
Keyword(s):  
Soil Water ◽  
Irrigation Scheduling ◽  
Pan Evaporation ◽  
Limited Effect ◽  
Class A ◽  
Drought Tolerant ◽  
Scheduling Model ◽  
Ipomea Batatas ◽  
Temporary Water ◽  
Class A Pan

Sweetpotato (Ipomea batatas L.) is a drought-tolerant crop mostly produced without irrigation. Consequently, sweetpotato may be exposed to temporary water stress. In 1997, an irrigation scheduling model using a water balance and class A pan evaporation (Ep) was evaluated with `Beauregard' on a loam sandy soil. The model was (12.7 DAT + 76) 0.5 ASW = DDAT-1 + [Ep (0.12 + 0.023 DAT – 0.00019 DAT2) – RDAT – IDAT], where DAT is days after transplanting (DAT = 0 on 20 June), ASW is available soil water (15%), D is soil water deficit (mm), R is rainfall (mm), and I is irrigation (mm). Root depth expanded at a rate of 13 mm/day to a maximum depth of 305 mm. Irrigation rates ranging between 0 and 145% of the model rate were created with sprinklers. The model scheduled 10 irrigations between DAT = 26 and 116 (harvest). Irrigation did not alter storage root quality, but did influence all the marketable grades (P < 0.01; R2 > 0.87). However, between 0 and 129% yield increases were linear and small, suggesting that the model overestimated sweetpotato water use. Thus, deficit irrigation between 50% to 70% of the model would have a limited effect on sweetpotato yields.

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.

Development and use of a variable-speed lateral boom irrigation system to define water requirements of 11 turfgrass genotypes under field conditions

2007 ◽  
Vol 47 (1) ◽  
pp. 86 ◽  
Author(s):  
D. C. Short ◽  
T. D. Colmer
Keyword(s):  
Water Conservation ◽  
Irrigation System ◽  
Water Status ◽  
Irrigation Scheduling ◽  
Variable Speed ◽  
Leaf Water Status ◽  
Area Index ◽  
Class A ◽  
Irrigation Requirements ◽  
Class A Pan

Improved irrigation scheduling is one strategy by which water management can be improved in turfgrass systems. The development and testing of a variable-speed lateral boom irrigation system for use in field-based irrigation trials is reported. Christiansen’s coefficient of uniformity was greater than 92% and the efficiency of irrigator discharge was greater than 90% for application depths (mm/unit land area) of 0.5–13 mm. The minimum irrigation requirements were determined for 11 turfgrass genotypes from a summer irrigation dose–response field trial that applied daily treatments of 100 (control), 80, 60, 40 and 20% of the previous day’s net evaporation measured using a US Class A pan. Responses of several shoot parameters, including clipping production, green leaf area index, leaf chlorophyll and leaf water status were evaluated to define minimum irrigation requirements for the turfgrasses. Minimum irrigation requirements (as defined by declines of 10% in several shoot responses) for C3 and C4 turfgrasses were 64–94% and 32–78% of US Class A pan, respectively. Variability in irrigation requirements within C3 or C4 types was due mainly to variations in estimates based on the different shoot parameters. The results demonstrate the opportunity for water conservation by using C4 rather than C3 turfgrasses in locations with hot dry summers (and mild winters) typical of a Mediterranean-type climate.

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