Modelo de distribución de agua en suelo regado por goteo

[ES] Se desarrolla un modelo de simulación de la dinámica del agua en el suelo en riego localizado, denominado SIMDAS. Para el desarrollo del procedimiento numérico, se utiliza la teoría de flujo de agua en condiciones de no saturación, sin efecto histerético, resolviendo la ecuación de flujo axisimétrico sin y con extracción de agua por la planta a partir de un método en diferencias finitas, con la consideración de los distintos horizontes del suelo. Verificado el modelo en campo, los resultados que presenta son satisfactorios cuando no se contempla la presencia de cultivo, pero no lo son cuando interviene la extracción de agua por la planta. Por consiguiente, el grado de aceptabilidad es suficiente para fines de diseño agronómico de sistemas de riego localizado, pero no lo es para aquellos casos en que la extracción de agua por la planta interviene de manera destacada, como en el manejo y la programación de riegos.Ramírez De Cartagena Bisbe, F.; Sáinz Sánchez, MA. (1997). Modelo de distribución de agua en suelo regado por goteo. Ingeniería del Agua. 4(1):57-70. https://doi.org/10.4995/ia.1997.2716SWORD577041Armstrong C.F., Wilson T.V. (1983) Computer model for moisture distribution in stratified soils under a trickle source. Transactions of the American Society of Agricultural Engineers: 1704-1709.Belmans C., Wesswling J.G., Feddes R.A. (1983) Simulation model of the water balance of a cropped soil: SWATRE. Journal of Hidrology. 63 & 21: 271-286.Ben-Asher J., Charach CH., Zemel A. (1986) Infiltration and water extraction from trickle irrigation source: The effective hemisphere model. Soil Science Society of America Journal. 50: 882-887.Brandt A., BreslerE., Diner N., Ben-Asher J., Heller J., Goldberg. (1971) Infiltration from a trickle source: I. Mathematical models. Soil Science Society of America Proceedings, 35: 675-682.Bresler R E. (1975) Two-dimensional transport of solutes during nonsteady infiltration from a trickle source. Soil Science Society of America Proceedings, 39: 604-613.Feddes R.A., Kowalik P.J., Zaradny H. (1978) Simulation of field water use and crop yield. PUDOC, Wageningen. 189pp.Ghali S.G. (1986) Mathematical modelling of soil moisture dynamics in trickle irrigated fields. Thesis, University of Southampton (UK).Gupta S.C., Larson W.E. (1979) Estimating soil wáter retention characteristics from particle size distribution, organic matter percent, and bulk density. Water Resources Research, 15(6): 1633-1635.Hillel D. (1977) Computer simulation of soil-waters dynamics. A compendium of recent work. IDRC, Ottawa, Canada. 214 pp.Jackson R.D. (1972) On the calculation of hydraulic conductivity. Soil Science Society of America Proceedings. 36: 380-382.Keller J. (1978) Trickle irrigation. In Irrigation (Ch. 7). National Engineering Handbook USDA-SCS.Keller J., Karmelid. (1975) Trickle irrigation design. Rain Bird Corp. Glendora, California USA. 133 pp.Khatri K.C. (1984) Simulation of soil moisture migration from a point source. Thesis, McGill University, Quebec, Canada.Kunze R.J., Uehara G., Graham K. (1968) Factors important in the calculation of hydraulic conductivity. Soil Science Soc. Amer. Proc., 32: 760-765.Lafolie F., Guenelon R., Van Genuchten M.TH. (1989a.) Analysis of water flow under trickle irrigation: I. Theory and numerical solution. Soil Science Society of America Journal, 53: 1310-1318.Lafolie P., Guenelon R., Van Genuchten M.TH. (1989b.) Analysis of water flow under trickle irrigation: II. Experimental evaluation. Soil Science Society of America Journal. 53: 1318-1323.Marino M.A., Tracy J.C. (1988) Flow of water through root-soil environment. Journal of Irrigation and Drainage Engineering, 114 (4): 588-604.Marshall T.J. (1958) A relation between permeability and size distribution of pores. Journal of Soil Science, 9 (8): 1-8.Millington R.J., Quirk J.P. (1959) Permeability of porous media Nature, 183: 378-388.Molz F.J., Remson I. (1970) Extraction term models of soil moisture use by transpiring plants. Water Resources Research, 6 (5): 1346-1356.Philip J.R. (1971) General theorem on steady infiltration from surface sources, with application to point and line sources. Soil Science Society of America Proceedings, 35: 867-871.Pradad R. (1988) A linear root water uptake model Journal of Hidrology, 99: 297-306.Raats P.A.C. (1977) Laterally confined, steady flows of water from sources and to sinks in unsaturated soils. Soil Science Society of America Journal, 41:294-304.Ramírez De Cartagena F. (1994) Simulación numerica de la dinámica del agua en el suelo. Aplicacion al diseño de sistemas de riego LAF. Tesis Doctoral. ETSEA. Universidad de Lleida.Rawls W.J., Brakensiek D.L. (1982) Estimating soil water retention from soil properties. Journal of the Irrigation and Drainage Division, Proc. of the ASCE, 108, IR2: 166-171.Saxton K.E., Rawls W.J., Romberger J.S., Papendick R.I. (1986) Estimating generalized soil-water characteristics from texture. Soil Science Society of America Journal, 50: 1031-1036.Taghavi S.A., Mariño M.A., Rolston D.E. (1985) Infiltration from a trickle source in a heterogeneous soil medium. Journal of Hidrology, 78: 107-121.Van Der Ploeg R.R., Benecke P. (1974) Unsteady, unsaturated, n-dimensional moisture flow in soil: A computer simulation program. Soil Science Society of America Proceedings, 38: 881-885Vermeiren L., Jobling G.A. (1986) Riego localizado. Estudios FAO Riego y Drenaje, n°36. FAO. Roma. 203 pp.Warrick A.W., Lomen D.O., Amoozegarfard A. (1980) Linearized moisture flow with root extraction for three dimensional, steady conditions. Soil Science Society of America Journal, 44: 911-914

Microbial Communities Under Distinct Thermal and Geochemical Regimes in Axial and Off-Axis Sediments of Guaymas Basin

Cold seeps and hydrothermal vents are seafloor habitats fueled by subsurface energy sources. Both habitat types coexist in Guaymas Basin in the Gulf of California, providing an opportunity to compare microbial communities with distinct physiologies adapted to different thermal regimes. Hydrothermally active sites in the southern Guaymas Basin axial valley, and cold seep sites at Octopus Mound, a carbonate mound with abundant methanotrophic cold seep fauna at the Central Seep location on the northern off-axis flanking regions, show consistent geochemical and microbial differences between hot, temperate, cold seep, and background sites. The changing microbial actors include autotrophic and heterotrophic bacterial and archaeal lineages that catalyze sulfur, nitrogen, and methane cycling, organic matter degradation, and hydrocarbon oxidation. Thermal, biogeochemical, and microbiological characteristics of the sampling locations indicate that sediment thermal regime and seep-derived or hydrothermal energy sources structure the microbial communities at the sediment surface

Group delay times of whistler-mode signals from VLF transmitters observed at Faraday, Antarctica

The group delay times (tg) of whistler-mode waves generated by the NAA (f= 24.0 kHz) and NSS (f = 21.4 kHz) U.S. Navy transmitters and recorded at Faraday, Antarctica (L= 2.3), after following a ducted field-aligned path are analysed theoretically for different L-shells of propagation using models of electron density, temperature, and ion composition distribution for typical day and night-time conditions. tg is presented as the sum of (1) a group delay time calculated for the simplest model of wave propagation parallel to the magnetic field in a cold, dense plasma with the effects of ions neglected (tgo) and (2) the corrections due to finite electron density, that is, finite ratio of electron plasma frequency to electron gyro frequency (Δtgc), contribution of ions (Δtgr), and non-zero electron temperature (Δtgh). It is pointed out that the correction Δtgc is the dominant one, while the ratioΔtgh/Δtgc is only about 1 % for L close to 2.3. The total correction Δtgs, = Δtgc + Δtgr + Δtgh at L = 2.3is about 10 ms and is to be taken into account when interpreting the measurements of tg. However, on the assumption of strictly longitudinal propagation, the parameter [tgm(NSS) – tgm(NAA)]tgm(NSS) [index m indicates measured parameters] can be used for estimating L without taking into account the corrections Δtgs, if we do not require an accuracy better than ± 0.02

Long Term Productivity Benefits of Soil Conservation

Please contact the NWISRL if you have a copy of this publication