Determination of Bridge Scour Velocity in an Estuary
Determination of the appropriate design for protection against bridge pier scour depends significantly upon the design velocities at the project site. In estuaries with large influences...
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...
Uncertainty Analysis of Reservoir Sedimentation
In estimating reservoir sedimentation, a number of uncertainties arise. These are related to annual streamfiow, sediment load, sediment particle size, trap efficiency, and reservoir operation....
Temporal Development of Local Scour at Bridge Piers
The temporal development of local scour depth at circular cylindrical bridge piers is considered. New data are presented and used to quantify the influence of flow duration on the depth...
Suspended-Solids Flux at a Shallow-Water Site in South San Francisco Bay, California
Time series measurements of current velocity and suspended solids-concentration (SSC) made during December 1993 and March 1994 at a shallow-water site in South San Francisco Bay were used...
Tributary No. 9 Restoration, Maryland State Highway Administration
The Maryland State Highway Administration agreed to accomplish restoration of 1,100 feet of stream channel as part of a mitigation agreement with the U.S. Army Corps of Engineers, Baltimore...
Assessment of Risks of Flooding by Use of a Two-Dimensional Model
In case of rare floods, the rivers might go far away from their minor bed, submerging large areas, eventually with relatively high velocities. One-dimensional models are not suitable to...
Scour at Culvert Outlets: Considerations Present and Future
One of the major considerations in the design and rehabilitation of the national transportation system is the conveyance of tributary drainage through constructed embankments. As drainage...
Three Dimensional Particle Tracking Model for the Sacramento-San Joaquin Delta
Flows into and out of the Sacramento-San Joaquin Delta are presently regulated in part by threatened and endangered fish species concerns. To aid in planning future project operations,...
Reducing Model Study Time and Improving Reliability
Historically, the majority of effort expended in computer modeling of physical systems has gone into the numerical algorithms used in the computer programs. Other aspects of modeling have...
Sound Way to Save Fish
Fish protection need not cost an arm and a fin. Using light and sound to spare fragile blueback herring and other species a harrowing fate, the U.S. Army Corps of Engineers devised a fish...
Pyramid Power
The pyramids of Giza in Egypt were built with limestone from nearby quarries, not concrete as some have theorized. The three main pyramids of Giza mark a highpoint of pyramid building...
Overview of Space Environmental Effects
The natural environment for low Earth orbit subjects satellites to various forms of damage, ranging from particulate impacts, ultraviolet light, atomic oxygen erosion and charged particle...
Helium-3 on the Moon: Model Assumptions and Abundances
Solar-wind particles are present in the outer few 100 angstroms of each soil particle of the Moon. Of particular interest, are the volatiles hydrogen (40-100 ppm) and helium (5-45 ppm)....
JSC-1: A New Lunar Soil Simulant
A new lunar soil simulant, JSC-1, has been developed and characterized under the auspices of the NASA Johnson Space Center. This simulant was produced in large quantities to satisfy the...
Assessing Effects for Disposal Sites off San Francisco
A simple particle tracking model has been used to estimate the size of deposition footprints and transient turbidity effects in the water column resulting from disposal of dredged material...
Effects of Flocculation on Particle Transport
On the basis of previous experimental and theoretical work on flocculation rates and the settling speeds of flocs, an accurate and computationally efficient model of the aggregation and...
Observations Related to the Use of the Sigma Coordinate Transformation for Estuarine and Coastal Modeling Studies
One of the common techniques used in application of time-dependent, three-dimensional models addressing estuarine and coastal environmental problems is the sigma coordinate transformation....
Issues Related to Modeling the Transport of Suspended Sediments in Northern San Francisco Bay, California
Measurements of suspended sediment concentrations at several deep-channel stations in San Francisco Bay are reviewed. Sediment concentrations are found to be strongly correlated with delta...
Second Order Directional Wave Kinematics in Shallow Water
A theory numerical procedure were developed earlier to represent a real sea by the sum of many linear and second order directional wave components. Earlier publications showed that including...
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