Estimation of Mean Velocity for Flow Under Ice Cover
Methods of estimating mean velocity in a vertical from point velocity measurements are compared for an ice-covered channel. The comparison is based on velocity profiles obtained from a...

Innovative Instrumentation for a Physical Model of River Ice Transport
Large physical models often require the use of innovative instrumentation and measurement techniques. Hydraulic models that attempt to simulate the effects of stationary ice covers put...

Recent Applications of Acoustic Doppler Current Profilers
A Broadband acoustic Doppler current profiler (BB-ADCP) is a new instrument being used by the U.S. Geological Survey (USGS) to measure stream discharge and velocities, and bathymetry....

Field Performance of an Acoustic Scour-Depth Monitoring System
The Herbert C. Bonner Bridge over Oregon Inlet serves as the only land link between Bodie and Hatteras Islands, part of the Outer Banks of North Carolina. Periodic soundings over the past...

Comparison of Current Meters Used for Stream Gaging
The U.S. Geological Survey (USGS) is field and laboratory testing the performance of several current meters used throughout the world for stream gaging. Meters tested include horizontal-axis...

Testing Turbine Aeration for Dissolved Oxygen Enhancement
During August of 1993 the Bureau of Reclamation tested turbine aeration for dissolved oxygen (DO) enhancement at Deer Creek Powerplant near Provo, Utah. This test required a variety of...

Eliminating Water Column Separation and Limiting Backspin at a 12,000-Horsepower Pumping Plant
Milwaukee's Water Pollution Abatement Program includes a deep tunnel system which collects combined sewage and street runoff during storms for later treatment when capacity is available...

A Computer-Controlled, Precision Pressure Standard
The operating principles as well as the technical aspects of the implementation of a precision pressure standard are presented here. The instrument can have dual use: either as a pressure...

Observations on the Growth of an Internal Boundary Layer with a Lidar Technique
The distribution of atmospheric water vapor across a step change in surface humidity (dry-wet) was observed by a Lidar measurement technique under neutral atmospheric stability condition....

Design and Execution of Hydrodynamic Field Data Collection using Acoustic Doppler Current Profiling Equipment
Proposed major changes to the navigation channel depth in the Cape Fear River prompted an investigation of the existing hydrodynamics of the river system. The observed data are to be used...

Sensitivity Analysis of Bridge Equations
Computation of riverbed scour at the 482,000-plus bridges over water in the United States of America requires a significant level of hydraulic engineering effort. To do cost-effective,...

Frequency of the 1993 Flood in the Upper Mississippi River Basin
The frequency of the 1993 flood in the upper Mississippi River Basin is characterized by applying Bulletin 17B and L-moment methods to 111 unregulated watersheds in the basin. The analysis...

Contraction Scour at a Bridge over the Iowa River
Flooding of the Iowa River during July and August 1993 caused extensive contraction scour at the State Highway 99 bridge over the Iowa River at Wapello, Iowa. At least 3.3 m of piling...

Effects of Flow Duration on Local Scour at Bridge Piers in New York
The relation of local scour to the duration of high flows and other hydraulic properties is being studied at 31 bridge sites in New York State. Clear-water scour is common at most of the...

Density-dependent Circulation in Desert-basin Aquifers with Isotropic Self-Similar Permeability Distributions
Closed-basin aquifers, typical of mountain chains in the western United States, present a central ephemeral lake (called `playa') where evaporation increases the local brine density creating...

Expert Analysis in Regulated Irrigation Canal Modelling
Application of riverine unsteady-flow numerical modelling techniques to problems of flow regulation in irrigation canals invokes the need for careful treatment of some situations not commonly...

Reservoir Operation by the Use of an Expert System
Most reservoirs, designed for the purpose of flood control, face operational problems during periods of drought. This study uses five indicators, streamflow, precipitation, temperature,...

Scada System Requirements for Optimum Pumping
In order to minimize the cost of electric energy for pumping water through its distribution system, a computer program was developed to schedule the operation at eight pumping stations...

Hydrodynamic Modeling of San Diego Bay
A two-dimensional vertically-averaged finite element model was adapted to study the hydrodynamics of San Diego Bay. The hydrodynamic model was interfaced with pre- and post-processors...

Near Field Behavior of a Far Field Circulation Model
Output from the 3-D far field circulation model ECOMsi was compared with output from EPA initial mixing models in two simulations of coastal sewage outfalls - an idealization with steady...

 

 

 

 

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