Hydraulic Features of Flexible Curtains Used for Selective Withdrawal
Flexible curtain barriers are being investigated as a way to modify power penstock intakes to achieve selective withdrawal. The curtain barrier controls the elevation from which water...
Modeling and Field Experiments for Tracer Gas Tests
Numerical modeling and field experiments were used to extend the tracer gas technique for determining surface gas transfer rates to shallow bays. Two-dimensional modeling was used to investigate...
Field Verification of Diffuser Performance
Effluent diffusers are used to gain relief from end-of-pipe acute toxicity criteria in NPDES water quality-based discharge permitting. Regulatory agencies require that the dilution provided...
Hatchie River and Schoharie Creek Bridge Failures
Within a 2-year period two large bridges collapsed into flooded rivers resulting in a total of 18 people plunging to their deaths. Both bridges had been inspected by probing, but had not...
Bridge Scour Vulnerability Assessment
Although the failure of the New York Throughway bridge over Schoharie Creek in 1987 has focused national attention on scour related failures, other failures reinforce the need for implementing...
Bridge Inspections Related to Bridge Scour
The failure of the Silver Bridge over the Ohio River in Point Pleasant, West Virginia, on December 15, 1967 resulted in the establishment of the National Bridge Inspection Standards (NBIS)...
A National Bridge Scour Data Collection Program
A study to collect and analyze field measurements of bridge scour is being conducted by the U.S. Geological Survey in cooperation with the Federal Highway Administration. The primary objective...
Evolution of Appropriate Technology
Although appropriate technology has been practiced since the beginning of people on earth, the inventiveness of the 20th century is forcing engineers (and others) to look at the multitude...
Environmental Considerations in Sustainable Development and the Application of Appropriate Technology
A fundamental appropriate technology concept is that technologies, as well as the development process, must be environmentally sound. As stated by the United Nations' World...
Health Benefits From the Use of Appropriate Technologies in Water Supply and Sanitation
Research on selected diseases in developing countries has found significant health impacts from water supply and sanitation interventions. Sanitation, personal and domestic hygiene, and...
Local Resources in Developing Country Water Supplies
Maximizing the use of local resources in water supply projects can expand markets for locally produced equipment and materials, reduce exports and minimize expenditures of hard currency...
Tailwater Concerns and the History of Turbine Aeration
All new proposals for hydropower development and many of the almost 300 hydroelectric projects which will be relicensed before 2000 will have to address the issue of minimum dissolved...
Overview of Autoventing Turbine Technology Development Project
Low concentrations of dissolved oxygen (DO) in the discharge of hydro plants represent one of the most significant environmental concerns confronting the hydropower industry. This is especially...
Model Tests for the Evaluation of Auto-Venting Hydroturbines
The most significant environmental problem for many hydroelectric facilities is the water quality of turbine discharges. The primary water quality problem is often low dissolved oxygen...
Experimental Difficulties Encountered in Testing Air/Water Mixtures
The Tennessee Valley Authority and Voith Hydro, Inc., are conducting a joint research project to study the effects of air admission on hydraulic turbines. Francis turbine models, homologous...
Modeling of Wetland Hydrodynamics and Transport in Coastal Louisiana
Modeling of hydraulics and transport of large wetland systems poses critical decisions between resolution of the complex geometry of a wetland and the testing required to meet study goals....
Hydrodynamic Modeling of Bolsa Chica, California, Proposed Wetland Enhancements
The California State Lands Commission (SLC) requested US Army Engineer Waterways Experiment Station (WES), Coastal Engineering Research Center (CERC), to conduct engineering studies for...
Finite Element Modeling of Flow in Wetlands
Requirements for developing a mathematical model of unsteady flow in wetlands are suggested. An equivalent continuum approximation is appropriate to avoid problems of describing the turbulence...
TABS-2 Application to Kawainui Marsh Flood Control
The TABS-2 mathematical modeling system was used to evaluate the effectiveness of alternatives designed to eliminate flooding problems in the Kawainui Marsh located in Kailua on the east...
Tidal Mass Exchange Between a Submersed Aquatic Vegetation Bed and the Main Channel of the Potomac River
Tidal mass exchange between a submersed aquatic vegetation (SAV) bed and the main channel of the Potomac River was investigated. Water levels were recorded at 5 minute intervals from August...
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