Journal of Irrigation and Drainage Engineering: Recent submissions

Now showing items 3341-3360 of 3826

    • Closure to “<i>Simulation Models of Sequences of Dry and Wet Days</i>” by J. W. Delleur, T. J. Chang, and M. L. Kavvas (June, 1989, Vol. 115, No. 3) 

      J. W. Delleur; T. J. Chang; M. L. Kavvas (American Society of Civil Engineers, 1991)

    • Critical Depth, Velocity Profile, and Channel Shape 

      R. J. Heggen (American Society of Civil Engineers, 1991)
      Critical depth can be defined as (1) The depth at which fluid velocity equals the speed of a gravity wave; (2) the depth at which the Froude number equals one; (3) the depth at which specific force corrected for velocity ...

    • Simulation of Wind‐Distorted Sprinkler Patterns 

      Ido Seginer; Dov Nir; R. D. von Bernuth (American Society of Civil Engineers, 1991)
      Single‐sprinkler wind‐distorted distribution patterns are simulated utilizing drop trajectory computations, and compared with measured patterns. It is found that the exact formulation of the drag coefficient of single drops ...

    • Closure to “<i>Roughness Values for Overland Flow in subcatchments</i>” by S. Y. Liong, S. Selvalingam, and D. K. Brady, (April, 1989, Vol. 115, No. 2) 

      S. Y. Liong; S. Selvalingam (American Society of Civil Engineers, 1991)

    • Alternative Linear Weir Design 

      Prabhata K. Swamee; Santosh K. Pathak; Mahesh Agarwal; Anwar S. Ansari (American Society of Civil Engineers, 1991)
      Weirs are devices installed in channels by means of which flow may be measured within a given degree of accuracy. Linear weir flow‐measuring devices introduce less relative error in discharge measurement. The design of a ...

    • Drainage of Clay Overlying Artesian Aquifer. II: Technical Analysis 

      I. C. Tod; M. E. Grismer (American Society of Civil Engineers, 1991)
      Subsurface drains in clay soil overlying a shallow artesian aquifer intercept water from the aquifer and the deep percolation from the root zone. Flow down the backfilled drain‐line trench is significant immediately after ...

    • Sensitivity of Reservoir Sizing to Evaporation Estimates 

      K. C. Gan; T. A. McMahon; I. C. O'Neill (American Society of Civil Engineers, 1991)
      Net reservoir evaporation is defined as the open water evaporation less the original evapotranspiration from the reservoir site. These rates are estimated on an average monthly basis by the method of Morton using sparse ...

    • Importance of Demand Estimation in Irrigation‐System Management 

      Numan Mizyed; Jim Loftis; Ramchand Oad; Alan Early (American Society of Civil Engineers, 1991)
      Systems engineering research is conducted to analyze improvements in performance of a water‐storage and ‐distribution system in response to improved monitoring of irrigation demands. The Mahaweli system in Sri Lanka, a ...

    • Irrigation of Small‐Level Basins in Egypt 

      Wadie F. Mankarious; Timothy K. Gates; Mohamed A.‐H. Rady (American Society of Civil Engineers, 1991)
      A major effort is under way to rehabilitate Egypt's vast irrigation system and to improve its management. To be effective, planning decisions must be in concert with irrigation needs at the farm level. Data on conventional ...

    • Centralized Scheduling Logic for Canal Operation 

      G. P. Merkley; W. R. Walker (American Society of Civil Engineers, 1991)
      Many schemes and devices have been developed and tested during the past three decades for automatic control of canal networks. Most of these have used local flow criteria to determine gate settings. Computer simulation of ...

    • Overseas Perspectives for Managing Irrigation Drainage in California 

      Emery M. Roe (American Society of Civil Engineers, 1991)
      International perspectives on irrigation organization provide new and useful ways of looking at old and increasingly difficult problems of drainage management in the United States. One particularly intractable issue at the ...

    • Drainage of Clay Overlying Artesian Aquifer. I: Hydrologic Assessment 

      M. E. Grismer; I. C. Tod (American Society of Civil Engineers, 1991)
      The performance of subsurface drains in a clay soil overlying an artesian aquifer is evaluated at a site in Imperial Valley, California. Field studies are undertaken to examine water and salt movement through the soil ...

    • Design Procedure for Flow over Side Weirs 

      Ali Uyumaz; Roger H. Smith (American Society of Civil Engineers, 1991)
      Numerical investigations of flow over side weirs in rectangular and circular channels are reported. Numerical models are obtained from energy principles and solved by a finite difference method. The results are presented ...

    • Practical Two‐Stage Pipe Expansions for Centrifugal Pumps 

      Walter L. Trimmer; John A. Fazio (American Society of Civil Engineers, 1991)
      Four two‐stage pipe expansions were designed, constructed, and tested to estimate their annual operating cost in irrigation service. The hydraulic performances of these fittings were compared with past two‐stage expansion ...

    • Sensitivity of Furrow Irrigation System Cost and Design Variables 

      J. Mohan Reddy; Horacio M. Apolayo (American Society of Civil Engineers, 1991)
      Considering the minimum cost as the objective, the furrow irrigation system design problem is formulated as an optimization problem. A combination of monotonicity analysis, constraint activity, and condensation are used ...

    • Interactive Computer‐Aided Design of Inverted Siphons 

      Pravi Shrestha; Johannes J. De Vries (American Society of Civil Engineers, 1991)
      An interactive computer program was developed for the design of inverted‐siphon conduits. In addition to the basic hydraulic processes involved in the design process, the program takes into consideration the head loss due ...

    • Problems and Potential of Irrigated Agriculture in Sub‐Saharan Africa 

      Mahmood Alam (American Society of Civil Engineers, 1991)
      Examination of 15 World Bank—funded irrigation projects in sub‐Saharan Africa revealed no specific pattern of project performance or cost of development of irrigated agriculture in the area. Some of the projects have been ...

    • Backwater Curves in Circular Channels 

      Willi H. Hager (American Society of Civil Engineers, 1991)
      Backwater curves in circular sewers and drainage conduits are considered by an explicit approach. The new method is based on simple expressions for uniform and critical flows, and a transformation of the longitudinal ...

    • Ditch Drainage in Layered Soils 

      H. C. Sharma; H. S. Chauhan; P. N. Kapoor; Sewa Ram (American Society of Civil Engineers, 1991)
      The assumption of considering the lower layer to be impervious, if its hydraulic conductivity is one‐fifth or less from that of the upper layer, leads to erroneous results. Many research workers have attempted solutions ...

    • Normal‐Depth Calculations in Complex Channel Sections 

      Edward D. Shirley; Vicente L. Lopes (American Society of Civil Engineers, 1991)
      The general problem of solving for normal flow depth in open‐channel flow has a complication in that some types of channel cross sections do not always have a unique solution. This paper analyzes an alternative iterative ...