Introduction— Given the reduction in water resources, irrigation should be carried out with the highest application efficiency. Irrigation pivots achieve application efficiencies close to localized ...systems; however, for citrus irrigation, the equations available for its design and management do not contribute to the efficient and rational use of water. Objective— Adapt the expression of the capacity of the machine and propose a new formulation for the discharge of the emitters, to adequately describe the operation of the central pivots for citrus irrigation. Methodology— Logical research methods were used and within these, the historical method and the deductive logic, to obtain the adequacy and the new equations presented. Results— The expression of the α coefficient was obtained to adapt the expression of the capacity of the machine and two new equations to calculate the necessary discharges of the emitters. They were applied to a case study. Conclusions— It was confirmed that the center pivot machines to irrigate citrus obtain water consumption and application efficiency comparable could with localized irrigation systems.
Introduction— The planting of 1 200 ha of citrus fruits is planned in the “Jiguaní” Agricultural Enterprise and, for the design and subsequent management of the irrigation systems, it is essential to ...previously establish the water needs of the crop. Objective— Calculate the water needs of citrus orchards using the procedures outlined by FAO-56, applying the most recent update of the Allen and Pereira (A&P) approach. Method— To calculate the water needs of the crop, the ETo × Kc approach established by FAO-56 was followed. Within this, the ETo values were calculated using the Hargreaves-Samani equation and those of Kc, from the update of the A&P approach. Results— Water needs vary between 1.0 d–1 and 1.9 mm d–1 for young orchards, from 1.7 mm d–1 to 3.5 mm d–1 for high-density adult plantations and low trees, and from 2.2 mm d–1 to 4.3 mm d–1 for tall trees. Conclusions— The pertinence of the A&P approach to estimate the Kcb and Kc coefficients to determine the water consumption of orchards benefited with localized and high-frequency irrigation techniques was corroborated.
Introduction: The use of the wind energy with practical ends is referred from old times; however at the present time it recovers validity for the necessity of finding alternative sources of energy in ...front of the conventional fossil fuel that is more and more scarce and it causes serious problems of environmental contamination. Objective: Design a windmill for the extraction of water in a simple and efficient way, from the principles of a multiblades windmill and the use of materials recovered in the locality that allows the irrigation of the garlic cultivation with sprinkle irrigation system at the minimum possible cost. Methodology: Different methodologies like the experience of the producers, established technical approaches for the selection of the relationship of speeds diameter of the rotor, coefficient of sustentation; haulage coefficient and attack angle were used. The analytic method was used for the calculation of the coefficient of solidity, the cord angles, the coefficient of power, the useful power, real flow, hydraulic power of the pump, total force in the piston, centrifugal force, sustentation force, drag force and the starting torque generated in a windmill. Results: They were obtained starting from the wind speeds registered in the locality during 30 years of systematic studies and the defined parameters and calculated for the wind rotor and the volumetric pump. It was possible to design a windmill with the mechanical and hydraulics characteristics appropriate to be used in the agriculture. Conclusions: The investigation demonstrated that the design of the windmill allows to complete the demands of the pumping of water for the irrigation system when guaranteeing a real flow of 0,17 L s-1 and a volume of water of 0,30 L displaced by the pump in each revolution of the wind rotor. The power generated by the wind rotor satisfies the power required by the pump.
Introduction: Groundwater constitutes the main source of water in the province of Ciego de Ávila, Cuba; especially in agriculture, which occupies the main economic line, however the overexploitation ...of aquifers in the southern basin of the province puts the sustainability of this important resource at risk, which is renewed through the natural recharge of rainfall. Objective: To determine the relationship between precipitation and groundwater levels in the hydrogeological sectors CA-II-2 and CA-II-3 of the Ciego de Ávila South Basin, which can constitute a way for the efficient use of water for irrigation purposes in this area of great agricultural importance. Methodology: In the development of the research, different methodologies were used: selection of the most representative rain gauges, calculation of effective precipitation, determination of accumulated monthly and annual rainfall; as well as the annual rainfall of the wet and dry periods, completion of rainfall series by the linear regression method, use of the HidroEsta 2 program to obtain the mean hiperanual rainfall and the historical mean levels, absolute minimum and maximum of all the selected wells. The mean rainfall of the area of the sectors was determined with the Isohyet method and the charts of hiperanual limnigrams were constructed using the BARHIS software. Results: The investigation showed that the average rainfall in the area is 1303.6 mm, higher than the historical average for the province. The water levels in the aquifer range between 0.84 and 12.98 m; where 7.21 m is the absolute average value. The year 1988 had great variations in rainfall, levels and the exploitation of groundwater. This study suggests the need to take measures that contribute to the rational use of groundwater in this overexploited basin due to the intensive use of water resources in agricultural irrigation. Conclusions: The study carried out was able to verify that the average rainfall in the area is 1303.6 mm, higher than the historical average for the province. The water levels in the aquifer range between 0.84 and 12.98 m, with absolute averages of 6.52 and 7.21 m respectively. The year 1988 presented high variability in rainfall, underground levels and the exploitation of groundwater.
The investigation was developed during the months of January until April of 2017, with the objective of evaluating the behavior of the pattern AquaCrop in the simulation of the agricultural yield of ...the dry bean crop under variables conditions of availability water. The investigation area belongs to the Cooperativa de Créditos y Servicios (CCS) Clemente Ramos, municipality of Bayamo, Granma province, which is located at the 20° 22' 57,1" of Latitude N and at 76° 38' 16,4" Longitude O, with a height of 52,50 msnm. A randomized experiment design was utilized, with three variants and three repetitions. The experimental variants were, mark of plantation of 0,07*0,7 m and 100 % of the evapotranspiration demand, mark of plantation of 0,07*0,7 m and 80 % of the evapotranspiration demand, mark of plantation of 0,05*0,55 m and 100 % of the evapotranspiration demand. The model simulated the canopy cover acceptably, when being achieved values of R2 (0,94; 0,94 and 0,92) and values of d (0,87; 0,77 and 0,73) for the three variants, while the values achieved in the simulation of air dry biomass under limitation conditions, alone they were acceptable the R2 0,99 and d 0,72 in the variant 1. The agricultural yield was simulated from an acceptable way when being achieved R2 98,88 and EAM 0,044.
The availability, quality and management of water constitute essential activities of national, regional and local governments and authorities. Historic annual rain (between 1961 and 2020) in Chambas ...River Basin (Central Cuba) was evaluated. Two remote sensing methods (Normalized Difference Water Index and RADAR images) were used to calculate the variation of water area and volumes of two reservoirs (Chambas II and Cañada Blanca) of Ciego de Ávila Province at end of wet and dry seasons from 2014-2021. The results showed that mean annual rain was 1330.9 ± 287.4 mm and it did not showed any significant tendency at evaluated period. For both reservoirs, mean water areas measured with two methods were 19 % and 8 % smaller than the mean water area reported by authorities for the same period. The static water storage capacity (water volume) of both reservoirs varied (as area) between seasons with the greatest volume in both reservoirs recorded in October of 2017 (30.5 million of m3 in Chambas II and 45.1 million of m3 in Cañada Blanca reservoir). Large deviations of water area and volumes occurred during the dry season (lower values) and the wet season of 2017 (influenced by rain associated to of Hurricane Irma) and wet season of 2020 (influenced by rain associated to tropical storm Laura). Calculated area – volume models with significant statistical correlation are another useful tool that could be used to improve water management in terms of accuracy and to increase reliable results in cases where gauge measurements are scarce or not available.
En la presente investigación se realiza el análisis del impacto provocado por la sequía agrícola en el cultivo del Plátano Vianda (Musa paradisiaca) en un período de 13 años en áreas de municipio de ...Venezuela de la provincia de Ciego de Ávila. Cuba, para el análisis de los períodos de sequía se utilizó el Índice de Sequía Agraria (ISA) el cual presenta dentro de su algoritmo matemático como variables determinantes la Evapotranspiración de Referencia, que en este caso se determinó con el método de Penman Monteith FAO-1998, el déficit de humedad, la precipitación efectiva y el rendimiento agrícola. Los resultados obtenidos demuestran que los procesos de sequías agrícolas se manifiestan en todos los ciclos del cultivo, afectando de manera general los rendimientos, la evaluación de fenómeno es de gran utilidad para el manejo sostenible de ecosistemas agrarios en aras de lograr mejores resultados productivos a mediano y corto plazo. El análisis de este fenómeno climatológico desde el punto de vista agrícola, permite trazar estrategias para la aplicación de métodos de conservación del suelo y del recurso hídrico a los agricultores.
La investigacion se desarrolló en el minicipio de Venezuela de la provincia de Ciego de Ávila, con el proposito de construir las curvas de intensidad frecuencia duracion de las inundaciones sobre la ...base de las precipitaciones efectivas de esa localidad y su ajuste a las funciones de Talbot y Aparicio. Se determinaron igualmente el índice de precipitación efectiva normal (IPN) de gran utilidad para la determinacion de la intensidad de este fenómeno. Los resultados demuestran que las precipitaciones efectivas máximas diarias indicaron escenarios de sequía severa en el año 2004 y exceso de precipitaciones en los años 2003 y 2007. El IPN demostró inundaciones fuertes en los años 2001 y 2007 en el mes de septiembre y severas en el 2003 es el mes de junio. Las curvas de Intensidad frecuencia y duración (IFD) de mayor ajuste se encontraron con el método de Aparicio para los periodos de retorno de 21, 11, 7, 5, 4, 3, 2 y 1 años con un coeficiente de determinación aceptable de 0,807. Palabras clave: Curvas número, precipitación efectiva, índice de precipitación normal. The research in the administrative area of Venezuela in the province of Ciego de Ávila was developed, with the purpose of building Intensity Duration Frequency curves (IDF) of flooding on the basis of effective rainfall of the town and its adjustment to the functions of Talbot and Aparicio. It also determined the normal effective precipitation index (NPI) useful for the determination of the intensity of this phenomenon. The results show that maximum daily effective rainfall scenarios indicated severe drought in 2004 and excessive rainfall in 2003 and 2007. The NPI showed strong floods in 2001 and 2007 in the month of September and severe in 2003 is the month of June. Intensity Duration Frequency curves (IDF) of greater adjustment were found with the method of Aparicio for return periods of 21, 11, 7, 5, 4, 3, 2 and 1 years with an acceptable determination coefficient 0,807. Keywords: Curves number, effective precipitation, normal effective precipitation index.
RESUMEN El cambio climático, ampliamente influenciado por diversos fenómenos identificados, ha afectado seriamente a diferentes sectores de la sociedad, amenazando la seguridad alimentaria y la ...productividad, realizar acciones para mitigar o adaptarse es vital en estos tiempos. Actualmente las tecnologías de la información y las comunicaciones juegan un papel importante en la extracción, transformación y carga de datos, por los grandes volúmenes de información almacenados. Muchas son las variables que intervienen en la identificación de cambios climáticos en todos los sectores, específicamente en la investigación se efectúa un análisis de series de datos cronológicos de precipitaciones diarias en el municipio de Venezuela, Ciego de Ávila, las cuales deben desestacionalizarse para mostrar un resultado óptimo para cualquier análisis posterior. Bajo esta premisa, el interés de este trabajo se fundamenta en la construcción de un software utilizando el lenguaje Python y el framework Django que permita desestacionalizar las series de datos cronológicas y permitan agilizar y tomar decisiones sobre la variabilidad del clima utilizando el modelado de datos, para lograr el objetivo se propone el método de los promedios mensuales. La información oficial es del Instituto de Meteorología de Ciego de Ávila, el cual prevé su utilización por los investigadores.
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