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Haie N.,International Water Resources Association | Haie N.,University of Minho | Keller A.A.,Keller Bliesner Engineering LLC
Water International | Year: 2014

Efficiency of water resources is essential; just as important is the terminology that describes it. Paradoxes in terminologies used by various international institutions and professionals in the agricultural, urban and environmental domains are examined. Integrated terminologies are proposed, starting from flow-path types in water balance and expanded into the "macro, meso, and micro-efficiencies" (3ME) formulation. The 3ME is a systemic framework based on the principle of the conservation of mass, integrating water-flow paths of a water system, their beneficial and quality attributes (the usefulness criterion), climate, and two types of water totals. These terminologies, with nine examples for urban (three types) and agricultural areas (rainfed, surface, drip and sprinkler), are used to discuss the 3ME framework and possible flawed policy implications. © 2013 International Water Resources Association. Source

Ella V.B.,University of the Philippines at Los Banos | Keller J.,Keller Bliesner Engineering LLC | Reyes M.R.,North Carolina A&T State University | Yoder R.,Yoder Consulting LLC
Applied Engineering in Agriculture | Year: 2013

Irrigation application using a low-cost microtube-type drip irrigation system tends to be relatively nonuniform especially under steep slopes and low operating pressure heads. This study was conducted to evaluate the effect of using a simple and inexpensive adjustable valve (AV) pressure regulator on water distribution uniformity of the low-cost microtube-type drip system under sloping conditions at various operating pressure heads. A 100 m2 microtube-type drip kit developed by the International Development Enterprises (IDE) was tested for water distribution uniformity with and without AVs under average operating pressure heads of 0.5, 1.0, and 1.5 m, submain slopes of 10%, 20%, and 30%, and lateral slope of 0%. Based on volumetric measurement of emitter discharge, the average Christiansen's coefficient of uniformity (CU) and Merriam and Keller's distribution uniformity (DU) values improved to a range of 76% to 94% and 64% to 91%, respectively, with AV adjustment. For all pressure heads and submain slope of 30%, CU and DU were increased by an average of 25% and 82%, respectively, with AV adjustment. Pair-wise t-test comparison (α=5%) of average CU and DU values for each setting showed significant improvement of water distribution uniformity except for a combination of a high pressure head of 1.5 m and steep slopes of 20% and 30%. These exceptional results suggest that at relatively steep slopes, the microtube-type drip system may be operated at relatively low pressure heads with proper AV adjustment to increase the water distribution uniformity. Results indicated that the use of AVs can significantly improve water distribution uniformity of the low-cost microtube-type drip irrigation system at low pressure heads even at slopes as steep as 30%, and offers the potential for maximizing crop yield in steep upland areas. © 2013 American Society of Agricultural and Biological Engineers. Source

Keller J.,Utah State University | Keller J.,Keller Bliesner Engineering LLC | Polak P.,Paul Polak Enterprises | Storaci P.,Ball Aerospace & Technologies | Yoder R.,Yoder Consulting
Resource: Engineering and Technology for Sustainable World | Year: 2013

Jack Keller, P.E., Paul Polak, Paul Storaci, and Robert Yoder are a team of professionals dedicated to improving the income of the rural poor. Presently, they are in the process of developing cost-effective PV-based, low-pressure irrigation systems and establishing a commercial enterprise to promote their adoption by farmers in India and other Asian counties. To afford a PV-powered pumping system supplying a lowcost drip system, and make a reasonable livelihood at the same time, smallholder farmers need to irrigate in the dry season, when vegetable prices are two or three times as high as they are during the rainy season, when everybody can grow vegetables. The best way to reach scale is to release market forces, creating opportunities for every participant in the market to earn a reasonable profit. Paul Polak Enterprises is partnering with volunteer engineers from Ball Aerospace, called the Design Revelation Employee Resource Group, for providing workshop facilities, and staff engineers and technicians are donating their time and talents as a contribution to this initiative. Source

Keller J.,Keller Bliesner Engineering LLC | Keller A.A.,Keller Bliesner Engineering LLC | Ray J.N.,International Development Enterprises India
American Society of Agricultural and Biological Engineers Annual International Meeting 2011, ASABE 2011 | Year: 2011

To profit from growing high value commodity, vegetable, and horticultural crops smallholder farmers need affordable irrigation products to get the most "crop per drop" and net income from small-plot (0.1 to 1 ha) irrigation systems. In view of this we have developed a generic Small-plot Irrigation Product (SIP) line that includes three types of drip, two types of sprinkle, and a piped surface irrigation application system. Simple to manufacture polyethylene layflat tubing of diameters between 16 mm and 75 mm and with thicknesses ranging from 125 to 900 microns is used for the pipe networks. The SIP drip systems are designed to operate at pressure heads of 1 to 3 m and cost between $500 and $600 per ha. They are the most efficient irrigation method in terms of both the volume of water required and the yield per unit of area irrigated as well as the yield per unit of water actually consumed by evaporation and crop transpiration. The SIP sprinkle systems are almost as efficient. They operate at pressure heads of 6 to 10 m, and cost about $400 per ha. The SIP row irrigation systems are designed to operate with pressure heads as low as 0.3 m and cost about $140 per ha. In addition to describing these SIPs, the content and application of a design manual for utilizing the SIPs and discussion of how they are being disseminated to smallholder farmers throughout the world is also included. Source

Haie N.,Keller Bliesner Engineering LLC | Pereira R.M.,University of Minho | Pereira R.M.,Keller Bliesner Engineering LLC | Machado G.J.,University of Minho | And 3 more authors.
Water Resources | Year: 2012

Multiple stresses are putting great pressure on water resources systems. Population growth, climate change, prosperity, energy production, food crisis, and water governance are among the factors straining water resources. Decision makers from rich to poor countries and from commercial to non-governmental organisations are struggling to devise schemes to adapt to these stressed water conditions. Better efficiency for water resources systems, and particularly irrigation systems, is recommended as one of the most important responses to climate change, unsustainable development, and water shortage. However, using certain efficiencies such as Classical Efficiency caused systems not to perform according to decision makers' objectives. Effective Efficiency is a robust composite indicator that includes in its formulation both a flow weight, taking into account the leaching fraction, and reuse of return flows. Classical Efficiency is defined as the percentage of the diversion consumed beneficially, such as by crop evapotranspiration. Effective Efficiency, on the other hand, is defined as the ratio of beneficial consumptive use to total consumption, expressed as a percentage. In this paper, a normalised and non-dimensional form of Effective Efficiency is developed and necessary constraints for its successful application are explained. These constraints express water balance, flow weights and their thresholds, water reuse, and total consumptive use. Basic guidelines are proposed for better decision making in determining possible interventions for improving Effective Efficiency. This is done by analysing its domain through analytical and graphical methods. Three real cases are considered, namely, Imperial Irrigation District and Grand Valley irrigation systems in the United States and Nile Valley in upper Egypt. Three-dimensional sensitivity analysis is performed on Effective Efficiency and its variables using the three cases. This leads to an examination of the validity of the analysis and to suggestions for better intervention options. Meanwhile, it is also shown why Classical Efficiency should be used with care. © 2012 Pleiades Publishing, Ltd. Source

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