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...
Subsurface Drainage for Erosion Reduction on Croplands of Northwestern Oregon
Subsurface drains installed as a relief system on sloping cropland reduced surface runoff and soil loss from silty soils with underlying slowly permeable layers in northwestern Oregon....
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...
Crop Production Models in Water Management
A weather generating model called WMAKER is introduced. The model generates daily climatic data based on the mean monthly values of temperature, precipitation, number of rainy days and...
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...
Hydrologic Design Criteria for Dams with Equal Reliability
Appropriateness of design criteria which require using the same Antecedent Moisture Condition (AMC) throughout Kansas for sizing dams and emergency spillways was examined. AMC values which...
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...
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'...
Bowen Ratio and Penman: Australian-California Tests
Results are presented of evapotranspiration (ET) studies conducted in Davis, California and at two locations in Australia. Good agreements were obtained in early comparisons of Bowen Ratio...
Calibration of an Evapotranspiration Model Using Eddy Correlation Methods
An evapotranspiration (ET) prediction model was developed by calibrating the H. L. Penman equation for an alfalfa reference crop in the southwestern Oklahoma region. Evaporative flux for...
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...
Dormant Season Evapotranspiration in Alfalfa
Weekly values of maximum temperature, minimum temperature, and solar radiation were examined for their effect upon weekly dormant season evapotranspiration (ETdorm) in perennial alfalfa....
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...
U.S. Bureau of Reclamation: How Irrigation Projects are Sized
The objective of this study was to review the methods presently used by the United States Department of Interior, Bureau of Reclamation (Bureau) to estimate the water requirements for...
Return to search