On Conductivity of Soils with Preferential Flow Paths
Laboratory soil column experiments were conducted to study the distribution of preferential flow paths resulting from removal of colloidal size clay particles. These experiments specifically...
A Comparative Study of the Transformed Methods for Solving Richards' Equation
The Richards' equation represents the movement of water in both saturated and unsaturated porous medium. The numerical solution to this equation is difficult because the algebraic...
Characterization of Canal Operations under Ideal Anticipatory Control
A dimensionless formulation of a gate.stroking model is being used to study general characteristics of control measures that need to be applied upstream in single.pool canal systems to...
Earth Spillway Design Using SITES Software
The USDA Natural Resources Conservation Service has, recently released new software for the design and analysis of water resource structure sites. This software, SITES, is based on the...
Long-term Consequences of Recycling Drainage Water for Irrigation
Several long.term field studies (i.e. 6 yrs or more) conducted by the USDA/ARS and the University of California have demonstrated that saline drainage water (ECw...
Alachlor Transport in Laboratory Soil Columns
Spraying of agricultural chemicals result in their travel downward through the unsaturated zone and adsorption to the surrounding soil. Infiltration from rainfall and irrigation solubilize...
Predicting Transport of Organics through Soil Columns using Distributed Mass-Transfer Rates
A numerical model to describe contaminant transport through soil columns, including distributed mass-transfer, is developed. Both a gamma distribution and a lognormal distribution are...
Delineating Subsurface Contamination Using Geostatistical and Non-Intrusive Geophysical Methodologies
Electromagnetic (EM) conductivity surveys are becoming a more practiced technique in screening for contamination of soil and groundwater. This non-intrusive geophysical approach detects...
Systems for Forecasting Flows and Their Uncertainty
Discussed are design issues of distributed systems for operational flow forecasting. Results of sensitivity analyses are presented which illustrate forecast flow dependence on model discretization...
Small Inocula Can Effect
This is the first report of colonization of soil by small numbers of a genetically engineered microorganism. The study suggests that the addition of small inocula of D5 to contaminated...
Studies on the Erosion of a Compacted Soil
In the management of water there are certain applications in which compacted soil is used (i.e., dams, embankments, levees, spiliways, and channels). Engineers rely primarily on field...
CHEMFLO Modeling of Aquifer Bioremediation in Vadose Zone
This paper deals with bioremediation in the vadose zone with an emphasis on using numerical models as a tool to ensure that the concentration of nutrients is maintained at a required level....
Development of Remediation Technologies Simulators
This paper summarizes on.going efforts to develop software for simulating various in situ, subsurface remediation technologies to improve remediation selection, design, and operation....
Dredging in the Southern Sacramento-San Joaquin Delta
The California Department of Water Resources and the United States Bureau of Reclamation are jointly conducting an environmental study and are proposing to release a draft Environmental...
Selection of Sediment Transport Relations: Part I, Review of Sediment Transport Comparisons
There are a great number of sediment transport relations in existence in the world today. The engineer is often faced with the problem of choosing the most appropriate relation for the...
Selection of Sediment Transport Relations Part III: Numerical Ranking of Sediment Transport Relations
The emphasis of this paper is the methodology for the selection of sediment transport relations and is applicable for analysis of any sediment transport relation. However, to illustrate...
Distributed Hydrologic Modeling of Humid Regions
Distributed physically-based hydrologic modeling of humid watersheds with shallow soils is complicated by non-Hortonian runoff production mechanisms. This paper presents a numerical experimental...
Fish Passage Pool Bedding Analysis
Anadromous fish passages, stream dynamics and the artifical channel segmented into a natural stream should fttnction seamlessly. This paper intends to develop reasonable procedures a designer...
On Silt Abrasion Erosion of Three Gorges Hydraulic Turbine in the Future
In this paper the basic parameters of Three Gorges hydraulic turbine have been reviewed and the operation characteristics of Three Gorges hydropower Station pointed out. Combined with...
Irrigation of Grain Sorghum on the Delmarva Peninsula
Irrigated grain sorghum experiments were conducted for two years on a Norfolk sandy loam soil. Full irrigation was compared to partial irrigation and no irrigation in a randomized block...
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