Browsing by Author "Yoder, R."

Now showing 1 - 8 of 8
  • Asian irrigation in transition: Responding to challenges
    Shivakoti, G. P. (New Delhi, India: Sage Publications, 2005)
    This book presents observations and informed views on what will be required of irrigation policies, institutions and governance for Asia and for the rest of the world.
  • Effect of hydraulic head and slope on water distribution uniformity of a low-cost drip irrigation system
    Ella, Victor B.; Reyes, Manuel R.; Yoder, R. (2008)
    Assessment of the effect of topography and operating heads on the emission uniformity distribution in drip irrigation systems is important in irrigation water management and could serve as basis for optimizing water use efficiency and crop productivity. This study was carried out to evaluate the effect of hydraulic head and slope on the water distribution uniformity of a low-cost drip irrigation system developed by the International Development Enterprises (IDE). The drip system was tested for water distribution uniformity under varying system heads and slope conditions. The laboratory experiments were conducted at the facilities of the College of Engineering and Agro-industrial Technology, University of the Philippines Los Baños. A drum reservoir served as water supply for the IDE drip system. A sub-main of 10 m and lateral-sub holder of 10 m with adjustable slope was fabricated to enable slope variations during laboratory experiments. The drip system was operated at pre-specified operating heads of 1.0 m, 2.0 m and 3.0 m for slopes of 0%, 10%, 20%, 30%, 40% and 50% for the sub-main and 0% slope for the laterals. The discharge in each emitter was monitored for each chosen slope through direct volumetric measurements. The water distribution uniformity was then evaluated using the Christiansen's method and the Merriam and Keller's method. Mathematical relationships were then developed to characterize the effect of slope and heads on uniformity coefficient. On the basis of the results, appropriate recommendations were formulated to minimize non-uniformity of water distribution under field conditions in sloping drip-irrigated lands.
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    Effect of hydraulic head and slope on water distribution uniformity of a low-cost drip irrigation system
    Ella, Victor B.; Reyes, Manuel R.; Yoder, R. (Blacksburg, VA: SANREM CRSP, 2008)
    Assessment of the effect of topography and operating heads on the emission uniformity distribution in drip irrigation systems is important in irrigation water management and could serve as the basis for optimizing water use efficiency and crop productivity. This study was carried out to evaluate the effect of hydraulic head and slope on the water distribution uniformity of a low-cost drip irrigation system developed by the International Development Enterprises (IDE). The drip system was tested for water distribution uniformity under varying system heads and slope conditions. The laboratory experiments were conducted at the facilities of the College of Engineering and Agro-industrial Technology, University of the Philippines Los Baños. A drum reservoir served as water supply for the IDE drip system. A sub-main of 10 m and lateral-sub holder of 10 m with adjustable slope was fabricated to enable slope variations during laboratory experiments. The drip system was operated at pre-specified operating heads of 1.0 m, 2.0 m and 3.0 m for slopes of 0%, 10%, 20%, 30%, 40% and 50% for the sub-main and 0% slope for the laterals. The discharge in each emitter was monitored for each chosen slope through direct volumetric measurements. The water distribution uniformity was then evaluated using the Christiansen's method and the Merriam and Keller's method. Mathematical relationships were then developed to characterize the effect of slope and heads on uniformity coefficient. On the basis of the results, appropriate recommendations were formulated to minimize non-uniformity of water distribution under field conditions in sloping drip-irrigated lands.
  • Effect of hydraulic head and slope on water distribution uniformity of a low-cost drip irrigation system
    Ella, Victor B.; Reyes, Manuel R.; Yoder, R. (St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2008)
    Assessment of the effect of topography and operating heads on the emission uniformity distribution in drip irrigation systems is important in irrigation water management and could serve as basis for optimizing water use efficiency and crop productivity. This study was carried out to evaluate the effect of hydraulic head and slope on the water distribution uniformity of a low-cost drip irrigation system developed by the International Development Enterprises (IDE), a non-profit organization dedicated to ending poverty in the developing world. The drip system was tested for water distribution uniformity under varying system heads and slope conditions. The laboratory experiments were conducted at the facilities of the College of Engineering and Agro-industrial Technology, University of the Philippines Los Baños. A drum reservoir served as water supply for the IDE drip system. A sub-main of 10 m and lateral-sub holder of 10 m with adjustable slope was fabricated to enable slope variations during laboratory experiments. The drip system was operated at pre-specified operating heads of 1.0 m, 2.0 m and 3.0 m for slopes of 0%, 10%, 20%, 30%, 40% and 50% for the sub-main and 0% slope for the laterals. The discharge in each emitter was monitored for each chosen slope through direct volumetric measurements. The water distribution uniformity was then evaluated using the Christiansen's method and the Merriam and Keller's method. Mathematical relationships were then developed to characterize the effect of slope and heads on uniformity coefficient. We found that the coefficient of uniformity (UC) and the emission uniformity (EU) generally increase with increasing heads and decrease with increasing slope. The coefficient of uniformity generally followed a linear relationship with either head or slope. The UC and EU decrease substantially at submain slopes steeper than 30%. For level surface, a head differential of 0.5 m does not cause significant change in either UC or EU. For all slopes tested, we found that a head of 3.0 m with respect to the junction of the most upstream lateral may be considered to be optimum from both hydraulic and practical standpoints. On the basis of the results, appropriate recommendations were formulated to minimize non-uniformity of water distribution under field conditions in sloping drip-irrigated lands.
  • Effect of hydraulic head and slope on water distribution uniformity of the IDE drip irrigation system
    Ella, Victor B.; Reyes, Manuel R.; Yoder, R. (2008)
    Assessment of the effect of topography and operating heads on the emission uniformity distribution in drip irrigation systems is important in water management and could serve as the basis for optimizing water-use efficiency and crop productivity. This study was carried out to evaluate the effect of slope and hydraulic head on the water distribution uniformity of a low-cost drip irrigation system developed by International Development Enterprises (IDE). The drip system was tested for water distribution uniformity under varying system heads and slope conditions. The experiments were conducted at the hydraulic laboratory facilities of the College of Engineering and Agro-industrial Technology, University of the Philippines-Los Baños. A drum reservoir served as water supply for the IDE drip system. A sub-main of 10 m and lateral-sub holder of 20 m with adjustable slope was fabricated to enable slope variations during laboratory experiments. The drip system was operated at pre-specified operating heads of 1 m, 2 m, and 3 m from the reservoir outlet for slopes of 0 percent, 10 percent, 20 percent, 30 percent, 40 percent, and 50 percent for the sub-main; and 0 percent slope for the laterals. The discharges in selected emitters were monitored under each chosen slope through direct volumetric measurements. The uniformity coefficient was then estimated using Christiansen's method. Mathematical relationships were then developed to characterize the effect of slope and heads on uniformity coefficient. On the basis of the results, appropriate recommendations were formulated to minimize non-uniformity of water distribution under field conditions in sloping drip-irrigated lands.
  • Improving the water distribution uniformity of a low-cost drip irrigation system using adjustable pressure-loss lateral takeoff valves
    Ella, Victor B.; Keller, J.; Reyes, Manuel R.; Yoder, R. (2010)
    This presentation explains a study conducted at the University of the Philippines Los Baños which measured the effect of using Adjustable Pressure-Loss Lateral Takeoff Valves (APLTVs) on the water distribution uniformity of a low-cost drip irrigation system under sloping conditions. These researchers used many calculations and graphs to show that in general, the inclusion of APLTVs as a built-in component of the low-cost drip irrigation system can potentially increase crop productivity and yield.
  • Technical note: A low-cost pressure regulator for improving the water distribution uniformity of a microtube-type drip irrigation system
    Ella, Victor B.; Keller, J.; Reyes, Manuel R.; Yoder, R. (2013-07-24)
    The use of low cost drip-irrigation systems represents a sustainable, practical and efficient water-saving and water-use technology; however, water distribution tends to be non-uniform, especially under steep slopes. This study sought to address this issue by evaluating the effect of an adjustable valve (AV) pressure regulator on water distribution uniformity. The inexpensive pressure regulator was tested on microtube type drip irrigation systems at the University of the Philippines Los Baños. It was found that the AV pressure regulator significantly improved the water distribution uniformity of the low-cost microtube-type drip irrigation system on relatively steep slopes, especially at low pressure heads.
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    Water distribution uniformity improvement of microtube-type and button-type drip irrigation system using adjustable pressure-loss lateral takeoff valves
    Ella, Victor B.; Keller, J.; Reyes, Manuel R.; Yoder, R. (Hokaido, Japan: International Commission of Agricultural and Biosystems Engineers (CIGR), 2012)
    Irrigation application using microtube-type and button-type drip irrigation systems tends to be relatively non-uniform especially under steep slopes and low operating heads. This study was conducted to determine the effect of using a device called Adjustable Pressure-Loss Lateral Takeoff Valves (APLTVs) on water distribution uniformity of both types of drip systems