Accuracy of Computed Water Surface Profiles
Stream cross-sectional geometry obtained from aerial surveys (aerial spot elevations and topographic maps) that conform to mapping industry standards are more accurate than is often recognized....

Effects of Land Subsidence on Flood Profiles
In this study, the effects of land subsidence on water-surface elevation and depth profiles during flood conditions were investigated for a large, hypothetical, slope-controlled stream....

Comparison of Some River Discharge Calculation Methods
To measure the discharge of a river, it is necessary to develop a stage-discharge curve based on water velocity at various cross sections of the river. This is the method which is used...

Sedimentation of Lakes and Reservoirs in Illinois
A generalized analysis of lake sedimentation rates in Illinois provides a representative 'window' on sedimentation rates of midwestern lakes located in humid...

Controlled-Drainage Supplements Subirrigation in Humid Regions
A computer simulation was conducted using climate and soil conditions of the humid southern U. S. to demonstrate optional operating methods for dual controlled-subdrainage/subirrigation...

Evaluation of Water Quality from a Drainage-Subirrigation System in Georgia
Nitrate-N, Ammonium-N and Phosphate-P concentrations were measured from shallow subsurface wells and outlets of a drainage-subirrigation system in the Georgia flatwoods for comparison...

Lessons from the Failure of a Needle Valve
In 1984 a manually operated, hydraulically actuated 66-inch needle valve ruptured due to water hammer. The circumstances that caused the failure were reconstructed through extensive analysis...

Choices Between Micro and Mainframe Computers
The explosion of microcomputers (PCs) has shifted a great amount of engineering computing from mainframes to micros. It has also shifted a lot of programming from FORTRAN to BASIC. This...

The Use of Spread Sheets in Water Resources Planning
With the advent of 'spread sheets' in the microcomputer explosion, a tool is available for the first time to greatly simplify many engineering procedures. This...

Models of Border Irrigation for Flat Clayey Soils
Border irrigation is widely used for irrigating pastures in south-east Australia. Inadequate earthworks, design and operation of irrigation layouts have been major causes of waterlogging...

Reducing Maintenance Costs of Irrigation Systems
Reducing the costs of maintaining an irrigation water delivery system is becoming more important as the financial problems of the irrigators become more critical. The maintenance costs...

Sprinkler Erosion Model
The Soil Conservation Service has developed a model to evaluate the effect of various sprinkler irrigation systems with associated agronomic practices. Many researchers have dealt with...

Delivery System Management Via Dynamic Programming
Management of irrigation water delivery systems may involve allocating limited water supplies over both time and space under uncertain future demands. The physical delivery systems are...

Interactive Surface Irrigation Design and Evaluation Software
This paper outlines the features and capabilities of a comprehensive personal computer software system for use by irrigation engineers in design and evaluation of continuous and surge...

A Simulation Procedure for On-Farm Irrigation Systems Planning
A simulation modeling package has been developed for modeling on-farm irrigation water supply and application systems. The modeling package can consider up to 6 different application systems...

Thermodynamic Factors in Evapotranspiration
Many of the methods discussed in this paper are refinements of procedures presented in the report 'Consumptive Use of Water and Irrigation Water Requirements'...

Effective Precipitation in Irrigation Design and Management
Effective precipitation is important in irrigation system design and operation. Numerous methods for estimating effective precipitation have been proposed in the past, including direct...

Shallow Groundwater Reuse in Alfalfa Irrigation
Two shallow groundwater reuse options in alfalfa irrigation are examined. Alfalfa water use from the water table is investigated using a drainage component model. It is shown that alfalfa...

On-Farm Management Alternatives to Reduce Subsurface Drainage in the San Joaquin Valley, California?Constraints to Implementation
The most cost effective approach for mitigating the drainage problem is incorporating on-farm management practices that reduce percolation and seepage losses to the shallow groundwater...

Subsurface Drainage System for the Klamath Project
The U. S. Bureau of Reclamation's Klamath Project was authorized in 1905 for irrigation purposes. A subsurface drainage system was constructed in the public lands within the...

 

 

 

 

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