Modeling Nitrogen Movement Through Loess Soils
This study evaluates the ability of the Root Zone Water Quality Model (RZWQM) to track the movement and fate of nitrate (NO3--N)...

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...

Effects of Wastewater Irrigation on Aqueous Geochemistry
A comprehensive assessment of the environmental impact of a full-scale, operating overland flow (OLF) land treatment system was made of the Campbell Soup, Inc. OLF system in Paris, Texas....

Pitfalls Associated with the Assumption of a Constant Partition Coefficient in Modeling Sorbing Solute Transport Through the Subsurface
This paper presents several case studies where the estimation of the adsorption coefficient, Kd, by means of the Koc-foc...

Predicting Incipient Fluidization of Fine Sands in Unbounded Domains
Fluidization systems in the coastal environment consist of a water pumping system and a source pipe buried in or near a tidal inlet to maintain a channel or to aid in sand bypassing. If...

Type Curves for a Slug Test in an Infinitely or Semi-infinitely Thick Aquifer
Type curves are provided for a slug test in an infinitely or semi-infinitely thick aquifer, the latter with the single confining layer immediately above or immediately below the well....

Well and Formation Losses
For design projects in the groundwater area, a step-drawdown test is commonly used to investigate the properties of the well-aquifer systems. Higher well and formation losses are usually...

Aquifer Measurements at Different Scales
Multilevel slug test data from five wells in a confined, sandy aquifer were analyzed to obtain an estimate of the vertical variation of the horizontal hydraulic conductivity, K(z). Hydraulic...

Terrain Conductivity to Define Groundwater Pollution
Electromagnetic terrain conductivity surveys were conducted at four animal waste lagoon sites in South Carolina in an effort to delineate groundwater contamination from animal waste lagoon...

Soil-Pesticide Grouping for Water Quality Management
Pesticide and soil properties contribute to changes in runoff and groundwater quality. Because pesticides have been found in runoff and ground water, those managing water quality need...

Concentration Measurements in Dense Leachate Plumes Using a Gamma Radiation System
An automated, nonintrusive technique is discussed that determines salt concentrations in dense leachate plumes. The dense plumes were introduced from a line source into a relatively narrow...

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...

Movable-Bed Model to Evaluate Nile River Dredging
About 200 km south of Cario, at Bani Mazar reach, the Nile River has widened and formed several islands. The result is three channels with shallow depths. One of the branches must be improved...

Fluidization Pipe Hole Spacing
Two-dimensional fluidization experiments are performed on fine (d50 = 0.15 mm) and medium coarse (d50 = 0.45...

Preventing Stilling Basin Abrasion
A 1:10 scale physical hydraulic model of Taylor Draw Dam outlet works was used to develop modifications to prevent back flow intake of rock into the stilling basin. Much of the back flow...

Experimental Model Study of Over and Under Baffles
A hydraulic model study of a chlorine mixing channel was conducted at the Hydraulic Research Laboratory of the City of Los Angeles. An arrangement of over-under baffles was used to facilitate...

Classification and Prediction of Buoyant Surface Discharges
Past efforts to predict the dilution and geometric characteristics of buoyant surface flows have relied on integral modelling techniques involving the solution of a series of differential...

A New Approach to Local Scour Depth Estimation Under a Horizontal Jet or Free Water Fall
A new formula is presented to estimate the local scour depth development with time due to a horizontal jet or free water fall based on a new approach which combines the concept of energy...

G.I.S. Applications in Nonpoint Source Pollution Assessment
A Geographic Information System (GIS) provides a flexible tool for developing the oftentimes cumbersome soils and land use mapping database required in watershed storm water management...

Fluid Mud Problems in Lakes, Reservoirs and Detention Ponds
An experimental study of wind induced surfacing of fluid mud bottoms in shallow water has been conducted. The experiments involved a channel placed within a wind tunnel, where a two-layered,...

 

 

 

 

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