Percolation Lysimeters for Water Quality Sampling
A field method to measure, year-around, the quantity and quality of leachate under irrigated crops has been developed. A specific objective was to evaluate percolation lysimeters as tools...
High Saline Water-Table Effect on Wheat Irrigation
Hydraulic, weighing lysimeters were used for five years to measure the effect of high, saline water tables on irrigation requirement of wheat. Each year the wheat was grown with no water...
Determining Criteria for Operating Irrigation Systems
Operation variables involved in the management of given irrigation systems are the irrigation time and the inlet head, when sprinkling or drip methods are applied, or the time of cutoff...
Surface-Drained Level Basins for Rice Production
Surface-drained level-basin systems, consisting of a series of terraced level basins in which a portion of the applied water is drained from the inlet end of the basin, can be used to...
An Analytical Technique of Flow Rate Into Perforated Draintubes
The flow rate into a draintube in a saturated soil media depends on numerous characteristics such as the hole size, the number and spacing of holes, the drain size and depth. Based on...
Effect of Choptank Watershed Drainage Project on Suspended Sediment Concentration
Between 1974 and 1982, the Soil Conservation Service, U.S.D.A. conducted a sediment concentration study on the Choptank Watershed in Caroline County, Maryland to monitor the effects of...
A Coupled Surface-Water and Ground-Water Model
In areas with dynamic and hydraulically well connected ground-water and surface-water systems, it is desirable that stream-aquifer interaction be simulated with models of equal sophistication...
Time Scales for Surface-Subsurface Flow Modeling
Traditionally, interactive free surface flow and subsurface flow are analyzed separately, using infiltration rate described by an infiltration formula as the common boundary condition....
Description and Evaluation of Program: CARIMA
The CARIMA code simulates unsteady free-surface flow in simple or multiply connected systems of rivers or canals. The simulation uses the Preissmann implicit finite-difference method for...
Surface Water/Groundwater Interaction Studies
Studies were performed on a high elevation (2440 meters or 8000 feet) valley stream system and a high (1980 meters or 6500 feet) cold desert stream system in Wyoming, to analyze the surface...
Cal Poly Model Canal
The Cal Poly Model Canal (located at the Water Delivery Facility, Irrigation Training and Research Center, California Polytechnic State University, San Luis Obispo, CA) was built to accommodate...
Geochemical Mass-Balance in a Small Forested Watershed in Southwestern Pennsylvania
An intensive hydrologic investigation of the North Fork Bens Creek Watershed on Laurel Hill in southwestern Pennsylvania was made during 1984-85. Precipitation was sampled weekly, and...
Rainfall-Runoff Characteristics of Rangitaiki and Whirinaki Watersheds
The Rangitaiki and Whirinaki watersheds in New Zealand have considerably higher storage and infiltration rates than others in New Zealand. The Rangitaiki watershed is flat compared to...
SRFR?A Model of Surface Irrigation?Version 20
The computer program, SRFR, comprises a mathematical model of flow in furrows, basins, and borders. It is designed for systematic, repeated application in the solution of design and management...
Two-Dimensional Analysis of Furrow Infiltration
A general applicable two-dimensional unsaturated-saturated model for transient soil-water flow conditions in heteogeneous soils was developed. The water flow model was applied to simulate...
The National Water-Quality Assessment (NAWQA) Program?A Basis for Water-Resource Policy Development
The concepts that are the basis for the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) program began forming in the early 1980's. By 1986,...
Flexible Supply Schedule Missing Link for Effective Surface Irrigation and Automation
Surface irrigation methods - furrow and border-strip are generally thought of as being inefficient and labor intensive. Careful evaluations have shown that as methods they can be very...
Improved HSPF Infiltration Calibration Procedure with a Linked GIS
A research project for the Florida Institute of Phosphate Research sought to develop an easy-to-apply integrated surface drainage model, HSPF, and groundwater model, MODFLOW, with a geographic...
Influence of Soil and Sediment pH and Redox Conditions on Degradation of Toxic Organics
The presence of toxic organics in soil and sediments has raised concern over persistence and bioaccumulation. In the absence of oxygen, microbial degradation of toxic organics proceeds...
Existing U.S. Standards in Hydraulic Engineering
The Task Committee on Recommendations for Standards in Hydraulics confined itself to topics that are used in hydraulic computations or design. Thus numerous standards related to size,...
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