D. Zerihun
University of Arizona
Subsurface flowIrrigation managementMathematical optimizationGeologyEngineeringInfiltration (hydrology)Pressure headLow-flow irrigation systemsSoil waterHydraulicsGeotechnical engineeringField (physics)InletInflowCutoffScale (ratio)Hydraulic simulationMathematicsHydrologyEnvironmental scienceComputer scienceSurface irrigationMechanicsFunction (mathematics)Mathematical modelEnvironmental engineeringAgricultural engineeringIrrigation
40Publications
9H-index
275Citations
Publications 40
#1D. ZerihunH-Index: 9
#2Charles A. SanchezH-Index: 26
Last. Hagler Mj
view all 4 authors...
This is the third manuscript of a three-part paper that presents the development and evaluation of a hydraulic simulation model for linear-move laterals equipped with pressure reducing valve (prvs). System description, model assumptions, and specification of the lateral hydraulic simulation problem are discussed in part-one of the paper. Formulation and numerical solution of the lateral hydraulic simulation problem are described in manuscript-two. Results of model evaluation and simulation examp...
#1D. ZerihunH-Index: 9
#2Charles A. SanchezH-Index: 26
This manuscript presents a hydraulic simulation model for linear-move sprinkler irrigation laterals equipped with pressure reducing valves (prvs). The linear-move lateral considered here consists of a series of arched spans with a specified geometry and multiple outlet-ports. Lateral diameter, hydraulic resistance characteristics, field slope, spacing between outlets, and sprinkler hydraulic characteristics can be constant or variable along a lateral. Lowpressure sprinklers, or spray nozzles, co...
#1D. ZerihunH-Index: 9
#2Charles A. SanchezH-Index: 26
An equation that expresses lateral pressure as an explicit function of distance from the lateral inlet is derived for linear-move sprinkler irrigation systems. The equation takes into account the effects of both field slope and span geometry on lateral pressure. The proposed equation is not intended for predictive use. Instead, it is used here in an additional evaluation of the validity of the unique pressure profile variability patterns, of linear-move laterals, produced in an earlier study thr...
#1D. ZerihunH-Index: 9
#2Charles A. SanchezH-Index: 26
Last. Eduardo BautistaH-Index: 13
view all 3 authors...
Source
#1D. ZerihunH-Index: 9
#2Charles A. SanchezH-Index: 26
Last. Eduardo BautistaH-Index: 13
view all 3 authors...
The pressure head profile of an irrigation lateral is a function of the hydraulic and geometric characteristics of the lateral and its slope. Slope effects on pressure variability along a lateral are typically limited. However, for a lateral with a spatially invariant parameter set well-defined relationships can be discerned between lateral slopes and the spatial patterns of the lateral pressure profiles. Thus, a comprehensive understanding of these relationships can be useful in the evaluation ...
Source
#1D. Zerihun (UA: University of Arizona)H-Index: 9
#2Charles A. Sanchez (UA: University of Arizona)H-Index: 26
AbstractLaterals constitute the basic element of a field-scale pressurized irrigation hydraulic network. The availability of accurate and robust computational methods applicable to lateral hydrauli...
Source
#1D. ZerihunH-Index: 9
#2Charles A. SanchezH-Index: 26
view all 5 authors...
In modern farming systems, fertigation is widely practiced as a cost effective and convenient method for applying soluble fertilizers to crops. Along with efficiency and adequacy, uniformity is an important fertigation performance evaluation criterion. Fertigation uniformity is defined here as a composite parameter consisting of irrigation and fertilizer application uniformity indicators. The field and computational procedures for sprinkler irrigation uniformity evaluation have been the subject ...
Source
view all 50 authors...
#1D. Zerihun (UA: University of Arizona)H-Index: 9
#2Charles A. Sanchez (UA: University of Arizona)H-Index: 26
Last. Arthur W. Warrick (UA: University of Arizona)H-Index: 33
view all 3 authors...
AbstractDroplet dynamics simulations are key to predicting sprinkler irrigation precipitation patterns. This paper includes derivations of equations describing droplet motion through a steady, uniform horizontal airflow (wind). The assumptions on which sprinkler irrigation droplet dynamics is based are stated, and the limitations they entail are highlighted. The motion of droplets is treated as an impulsively started accelerated motion of rigid spheres, originating at the sprinkler nozzle with k...
5 CitationsSource
#1D. Zerihun (UA: University of Arizona)H-Index: 9
#2Charles A. Sanchez (UA: University of Arizona)H-Index: 26
Last. Arthur W. Warrick (UA: University of Arizona)H-Index: 33
view all 3 authors...
AbstractA system of equations, with strong physical basis, was derived for sprinkler irrigation droplet dynamics in the companion paper. Numerical solution of these equations and model evaluation is discussed in this paper. With the aim of enhancing computational efficiency and robustness, the droplet dynamics equations were scaled using four characteristic variables: characteristic time, length, velocity, and density. The characteristic time, length, and velocity are derived based on considerat...
1 CitationsSource