239 research outputs found

    La carrera científica en el CSIC

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    31 Pags.- Tabls.- Figs. Creative Commons License Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)Peer reviewe

    Simulación bidimensional del riego por inundación con microtopografía

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    [ES] En este artículo se describe la implementación de modelos bidimensionales del riego por inundación considerando la microtopografía del terreno. Se discuten los fundamentos teóricos de los modelos bidimensionales del flujo en lámina libre, su utilidad en el riego por superficie y la aplicación del procedimiento numérico "leapfrog" a la resolución de las ecuaciones diferenciales que gobiernan este tipo de flujo. La inclusión de la microtopografía en la modelación del riego por inundación aumenta sustancialmente el número de datos necesarios, pero puede permitir caracterizar la relación entre microtopografía y rendimiento del riego. Esto resulta particularmente interesante en nuestros días ya que la técnica de explanación guiada por rayo láser permite a los agricultores un mayor control sobre el estado de explanación de sus canteros. Finalmente, se analiza un caso hipotético para ilustrar el funcionamiento del modelo en un cantero a nivel con microtopografía. Los resultados indican que una deficiente explanación distorsiona la configuración del frente de avance, retrasa la fase de avance, induce variabilidad en el tiempo de receso y reduce la uniformidad y rendimiento potencial del riego.Playán Jubillar, E. (1994). Simulación bidimensional del riego por inundación con microtopografía. Ingeniería del Agua. 1(4):101-111. https://doi.org/10.4995/ia.1994.2651SWORD10111114Akanbi, A. A. y Katopodes, N. D. (1988) Model for flood propagation on initially dry land, J.Hyd. Div. (ASCE), 114(HY7), 689-706.Bucks, D. A. y Hunsaker, D. J. (1987) Water use variability in irrigated level basins, Transactions of the ASAE, 30(4), 1090-1098.Katopodes, N. D. y Streikoff, T. (1977) Hydrodynamics of border irrigation - complete model, J. Irrig. Drain. Div. (ASCE), 103(IR3), 309-323.Leão de Sousa, P., Countinho, J. M. y Baguinho de Sousa, J. M. (1993) O nivelamento de precisão e a sua manutenção. Condições essenciais para a automatização da rega de superfície, En: Desenvolvimento de equipamentos mecanizados para rega de gravidade. P. Leão de Sousa and M. R. Cameira, Eds. ISA/DER, Universidade Técnica de Lisboa, Lisboa, Portugal. 149 pp.Playan, E. (1992) Two dimensional hydrodynamic simulation of basin irrigation: analysis of field shape effects on irrigation performance, Ph. D. thesis, Utah State University. 143 pp.Playán, E., Walker, W. R. y Merkley, G. P. (1994a) Two-dimensional simulation of basin irrigation. I: Theory, J. Irrig. Drain. Div. (ASCE), 120(5):837-856.Playán, E., Walker, W. R. y Merkley, G. P. (1994b) Two-dimensional simulation of basin irrigation. II: Applications, J. Irrig. Drain. Div. (ASCE), 120(5):857-870.Samper, F. J. y Carrera, J. (1990) Geoestadística: Aplicaciones a la hidrología subterránea. Centro Internacional de Métodos Numéricos en Ingeniería, Barcelona, España. 484 pp.Walker, W. R. (1989) Guidelines for desinging and evaluation surface irrigation systems. FAO irrigation and drainage paper 45. Food and Agriculture Organization of the United Nations, Roma, Italia. 137 pp

    Controladores de riego automáticos en cobertura total de aspersión: oportunidades y limitaciones

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    1 .pdf (53 Pags.) copia de la presentación del autor en el Curso. Se acompaña de 1 .pdf con información general y contenidos del Curso organizado por DMACS-Universitat de Lleida, LabFerrer, IRTA.Syllabus 1. Introduction. 2. Sprinkler irrigation: a risky business 3. Opportunities for improved irrigation management. 4. (A possible) future of automatic sprinkler irrigation systems. 5. An experiment: an automatic irrigation controller. 6. Design alternatives. 7. Identifying Bottlenecks. 8. ConclusionsPeer reviewe

    Simulation of basin irrigation scheduling as a function of discharge and leveling

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    [EN] Irrigation scheduling was simulated on several case studies involving basin irrigation for two crops and twolocations using a two-dimensional irrigation model. The crops were wheat and alfalfa, and the locations hadreference evapotranspiration of 1,194 and 926 mm year-1, respectively. Two variables were considered at the farmlevel: inflow discharge and quality of land leveling. Considered discharges ranged from 0.05 to 0.20 m3s-1. Thequality of land leveling was characterized by means of the standard deviation of surface elevation (SD), rangingfrom 0 to 30 mm. Results indicated that increasing the discharge from 0.05 to 0.20 m3 s-1reduces the number ofirrigations by an average 32%. As for land leveling, if the SD was improved from 30 to 0 mm, the number of irri-gations would be cut by 22%. Low discharge and poor leveling are associated with low application efficiencywhich results in important seasonal deep percolation losses.[ES] Se realizó una simulación de una programación de riegos para varios casos con riego por inundación mediante un modelo hidrodinámico bidimensional. La programación se realizó para dos cultivos y dos localidades. Los cultivos fueron trigo y alfalfa, y las localidades fueron Zaragoza y Daroca con evapotranspiración de referencia de 1.194 y 926 mm año elevado a-1, respectivamente. Se consideraron dos variables de riego, relacionados con el diseño y el manejo. La primera de las variables fue el caudal de riego, para el que se consideraron valores de 0,05 a 0,20 m3 s elevado a -1. La calidad de la explanación, cuantificada con la desviación estándar de la elevación del terreno (SD), fue la segunda variable utilizada. Se utilizaron valores de SD de 0 a 30 mm. Los resultados indicaron que el aumento del caudal de 0,05 a 0,20 m3 s elevado a -1 reduce el número de riegos estacionales en un 32% en promedio. En cuanto a la explanación, si se mejorara la SD de 30 a 0 mm, el número de riegos estacionales se reduciría en un 22%. Un bajo caudal de riego y una mala calidad de la explanación se traducen en una baja eficiencia del riego por inundación que produce un volumen importante de pérdidas por percolación profunda.Peer reviewe

    Modelización de fertirrigación en redes de surcos

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    En XXVI Congreso Nacional de Riegos, Huesca, 24 a 26 de junio de 2008.El riego por surcos es uno de los sistemas más de riego más antiguos y más utilizados en el mundo. La simulación de la aplicación de fertilizantes disueltos en el agua (fertirrigación) en riego en redes de surcos es una herramienta que puede resultar muy útil para la optimización del riego. En este trabajo se presenta un modelo de simulación que incorpora las últimas novedades y refinamientos desarrollados en los últimos años tanto en los modelos de rozamiento, infliltración y difusión de solutos como en la resolución numérica y el tratamiento de las condiciones de contorno. Las propiedades matemáticas del modelo propuesto se demuestran en varios tests con solución analítica y en varios experimentos de fertirrigación en surcos. Además se presenta la aplicación del modelo para la optimización de la aplicación de fertilizante en fertirriego en surcos. La principal conclusión extraída es que con riego por surcos bien nivelados se puede lograr altas eficiencias y uniformidades de aplicación capaces de competir, para cultivos que se pueden adaptar a este sistema, con los más modernos sistemas de riego.Peer reviewe

    Solute transport modeling in overland flow applied to fertigation

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    A model of solute transport in overland flow is developed and applied to the simulation of surface fertigation. Water flow is simulated using the depth-averaged, 1D shallow water equations. Solute flow is represented by an advection-diffusion model. The resulting set of three partial differential equations is sequentially solved at each time step. First, water flow is computed using the explicit two-step McCormack method. Based on the obtained velocity field, solute transport is explicitly determined from the advection-diffusion equation using the operator split technique. Four field experiments involving fertigation events on an impervious free-draining border were performed to validate the proposed model and to obtain estimates of Kx, the longitudinal dispersion coefficient. A value of Kx = 0.075 m2 s-1 satisfactorily reproduces the field experiments. The model is also applied to the simulation of a fertigation event on a pervious border. A sensitivity analysis is performed to assess the dependence of fertilizer distribution uniformity on the value of Kx. Finally, the proposed model is compared with a previous model based on pure advection.The writers would like to express their gratitude to the CONSI+D of the Government of Aragón, Spain. Their Grant PCA1094 made this research possible. Thanks are also due to the INIA of the government of Spain for granting a scholarship to N. Zapata.Peer Reviewe

    Research group "Irrigation, agronomy and the environment"

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    28 Pags.- Fots.- Figs.- Tabls. Creative Commons License Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0).Research Group Objective: Generate scientific and technological information in the “soil-water-cropatmosphere” interface leading to more competitive, efficient and sustainable agricultural systems with emphasis on irrigation, agronomy and the environment, and with an applied-research focus.Research Group Priority Lines: 1- Sustainable use of water and soil resources 2- Environmental impact of agricultural activities 3- Crop agronomyPeer reviewe

    Field test of an automatic controller for solid-set sprinkler irrigation

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    13 Págs., 4 Figs., 5 Tabls. The definitive version is available at: http://link.springer.com/journal/271The application of new technologies to the control and automation of irrigation processes is becoming very important, and the automatic generation and execution of irrigation schedules is receiving growing attention. In this paper, a prototype automatic irrigation controller for solid-set systems is presented. The device is composed by software and hardware developments. The software was named Ador-Control and it integrates five modules: the first four modules simulate drop trajectories, water distribution, crop growth and yield, and the last module ensures bidirectional communication between software and hardware. Decision variables based on soil, crop, and irrigation performance indexes were used to make real-time irrigation decisions. A randomized experimental design was designed to validate the automatic controller over a corn crop during two seasons. Three treatments were analyzed: T0) manual programmer or advanced farmer; T1) automatic scheduling controlled by indexes based on soil simulated water content and irrigation performance; and T2) advanced automatic scheduling controlled by simulated thresholds of crop and irrigation indexes. Experimental results in 2009 and 2010 indicated that automatic irrigation treatments resulted in similar maize yield but using less water than manual irrigation (10 % between T0 and T1, and 18 % between T0 and T2). © 2012 Springer-Verlag Berlin Heidelberg.This research was funded by the MCINN of the Government of Spain through grants AGL2007-66716-C03-01/02 and AGL2010-21681-C03-01Peer reviewe

    Assessing Sprinkler Irrigation Performance Using Field Evaluations at the Medjerda Lower Valley of Tunisia

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    10 Pags., 6 Figs., 7 Tabls.Irrigation uniformity and wind drift and evaporation losses (WDEL) are major concerns for the design and management of sprinkler irrigation systems under arid or semi-arid conditions. Field trials were carried out to assess irrigation uniformity and WDEL under various wind velocities, sprinkler spacings and operating pressure heads. Based on experimental data, a frequency analysis was performed to infer the occurrence probability of a given uniformity coefficient (UC). In addition, statistical regressions were used to model WDEL as a function of different climatic variables. Increasing the operating pressure head improved uniformity at low wind speeds. It was shown that UC has been severely impaired at wind speeds above 4 m/s. In the prevailing wind conditions, the frequency analysis showed that a sprinkler spacing of 12 m × 12 m provided the best uniformity. In the local conditions, it is recommended to stop irrigation when wind velocity exceeds 4 m/s. Moreover, it was shown that wind speed and relative humidity were the main significant variables influencing WDEL.The authors are thankful to the INRGREF for the valuable support of this research.Peer reviewe
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