Journal of Irrigation and Drainage Engineering: Recent submissions
Now showing items 3641-3660 of 3826
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Canal Design: Optimal Cross‐Sections
(American Society of Civil Engineers, 1987)Canal cross‐section designs for uniform flows are contrasted and compared by using nondimensional shape parameters. The basic relations among the cross‐section shapes and design variables (the wetted perimeter, the water ... -
Alternative Metric Units for Acre‐Foot and Acre‐Inch
(American Society of Civil Engineers, 1987)Acre‐foot is an important water measurement term in the United States, particularly in the American west. Although less common, its derivative, acre‐inch, is widely used within the irrigation community. No meaningful ... -
Closure to “<i>Economic Consideration of Deficit Irrigation</i>” by George H. Hargreaves and Zohrab A. Samani (December, 1984)
(American Society of Civil Engineers, 1987) -
Simplified Irrigation Scheduling and Crop Selection for El Salvador
(American Society of Civil Engineers, 1987)A unique condition exists for the country of El Salvador: By knowing only the elevation, the type of crop suitable for the area and the crop water requirement can be evaluated. This paper shows how elevation can be used ... -
Improving Tubewell Irrigation System Performance
(American Society of Civil Engineers, 1987)Results of a field investigation on 10 selected deep tubewell irrigation systems in Bangladesh are presented. Development and application of a service area model to predict the impact of various improvement options are ... -
Drainage of Sloping Lands with Constant Replenishment
(American Society of Civil Engineers, 1987)An analytical solution is derived using the Boussinesq equation to describe an unsteady rising water‐table profile in an aquifer lying over a mildly sloping impervious bed in response to constant replenishment. A Hele‐Shaw ... -
Irrigation Efficiency: Economic Interpretation
(American Society of Civil Engineers, 1987)To clarify the nature of irrigation efficiency, economic efficiency is defined and its relation to technical efficiency examined. Yield efficiency in water demand and cost efficiency in water supply are both necessary for ... -
Furrow Irrigation Using Canal Side Weirs
(American Society of Civil Engineers, 1987)The potential of canal side weirs for uniform water delivery to irrigation furrows and system flexibility is assessed. Weir discharge uniformity is affected by: (1) Canal velocity and weir entrance conditions; (2) variations ... -
Modeling Saturated‐Unsaturated Water Flow in Soils
(American Society of Civil Engineers, 1987)A model for the transient one‐dimensional water movement in the saturated‐unsaturated zone using a finite difference method with stochastic inputs is developed. Hysteresis in the soil water retention and hydraulic conductivity‐ ... -
Evaluation of Simple, Dynamic Soil Moisture Model
(American Society of Civil Engineers, 1987)The dynamics of soil moisture in the root zone is of fundamental importance in agricultural water management. A simple, yet physically based model is presented which describes the processes of redistribution of the soil ... -
1‐D, 2‐D, and 3‐D Infiltration for Irrigation
(American Society of Civil Engineers, 1987)Models for one‐, two‐, and three‐dimensional infiltration for irrigation are derived using an energy equation and Darcy's law. The models were verified with Fok and Chiang's (4) experimental data. A good agreement is found ... -
Discussion of “<i>Economic Consideration of Deficit Irrigation</i>” by George H. Hargreaves and Zohrab A. Samani (December, 1984)
(American Society of Civil Engineers, 1987) -
Mechanical‐Hydraulic Dual‐Acting Controller for Canal Level or Discharge Rate
(American Society of Civil Engineers, 1987)A control device has been developed for canal structures, which can be used to control upstream water levels, downstream water level, or off‐take canal discharges. The system uses no electrical power or electronics. It is ... -
Flow Over Sharp‐Crested Plate Weirs
(American Society of Civil Engineers, 1987)For flow past a two‐dimensional sharp‐crested weir located at the end of a horizontal rectangular channel, experimental results related to velocity and pressure distributions in the region of the nappe close to the weir ... -
Generalized Mein‐Larson Infiltration Model
(American Society of Civil Engineers, 1987)The Mein‐Larson extension of the Green‐Ampt infiltration model is extended further to analyze the infiltration process under a variable rain on a covered natural soil. Such a condition represents the infiltration under ... -
Irrigation Effects in Six Western States
(American Society of Civil Engineers, 1987)Results of field and laboratory studies performed over the past 20 years in Idaho, Montana, Nevada, Oregon, Utah, and Washington are reviewed. The studies varied in number, intensity, and breadth from state to state, but ... -
Terminology for Describing Irrigation Conveyance Systems
(American Society of Civil Engineers, 1987)A terminology for describing irrigation conveyance systems is presented. It is modeled after one introduced by the International Commission on Irrigation and Drainage (1978), and Bos (1979) and (1985); however, this work ... -
Wastewater Criteria for Irrigation in Arid Regions
(American Society of Civil Engineers, 1987)With rapid growth of agriculture coupled with increasing population and urbanization, the demand for water in the Kingdom of Saudi Arabia is continually on the increase, causing alarming drawdown in the deep aquifers, the ... -
Irrigation Effects in Oklahoma and Texas
(American Society of Civil Engineers, 1987)Groundwater contamination is a serious water quality problem since 50% of the population derives drinking water from groundwater sources. Severe water quality problems have resulted from deep percolation under irrigated ... -
Seepage into Variably Saturated Porous Medium
(American Society of Civil Engineers, 1987)A numerical model is developed for simulating the interaction of a surface water body with a variably saturated porous medium. A boundary condition simulating the soil‐water pressure head at the boundary between the porous ...