Measuring Soil Bulk Density Profiles with a Single Probe Gamma Density Gauge
Calibrating neutron depth gauges for measuring soil water content profiles requires soil bulk density data. In this study, the feasibility of using a single probe gamma density gauge to...
Error Analysis of Bulk Density Measurements for Neutron Moisture Gauge Calibration
Six bulk density sampling methods were evaluated for use in neutron gauge calibration. All six methods provided estimates of bulk density which were generally within 5% of bulk density...
Neutron Gauge Calibration Comparison of Methods
Several methods for obtaining soil samples for determining soil water content were used for field calibration of neutron gauges. This paper compares the results of calibration curves obtained...
Effect of Moisture and Bulk Density Sampling on Neutron Moisture Gauge Calibration
Three moisture and bulk density sampling methods were evaluated for use in neutron gauge calibration. Each of the methods was comprised of a single core or portions of a core taken during...
London Linkage
Although it measures just 1.8 km, the Limehouse Link tunnel in London is both a complex engineering project and a gateway to urban renewal. The link is a $350 million highway tunnel connecting...
The Influence of Slope and Surface Roughness on Trapezoidal Free Overfall Characteristics
The brink depth-discharge relationship for trapezoidal free overfalls was investigated including the effects of slope and roughness. The theoretical relationship is based on the momentum...
Optimization Modeling for Sedimentation in Alluvial Rivers Considering Uncertainties
A nonlinear optimization model is formulated for determining optimal reservoir releases to minimize channel bed aggradation and degradation in downstream rivers. The model is based upon...
Environmental Control of Wetland Plant Communities
We have determined hydrologic regimes at a variety of sites while conducting studies to identify factors controlling wetland plant community composition and distribution. We have had relatively...
A Model for Low-Drag Landslides
Field observations and experimental records indicate that the primary mode of motion of many large landslides is that of sliding rather than flowing. Most of the shear during sliding is...
Simulation of Subsurface Drainage of Highway Pavements
An analysis of the drainage of a pavement system from initial saturation incorporates a realistic assessment of the drainable porosity of the base. This analysis indicates that if a granular...
San Francisco Bay and Delta Oil Spill Fate Studies Part I: Hydrodynamic Simulation
A two-dimensional vertically-averaged finite element model was used to simulate the hydrodynamics in San Francisco Bay and Delta to support oil spill fate studies. Simulations were performed...
San Francisco Bay and Delta Oil Spill Fate Studies Part II: Oil Spill Simulation
Because of the presence of oil refineries and significant tanker and barge traffic in the bay and delta region, the possibility of a moderate or major spill in the area must be considered....
Incipient Motion in Gravel-Bed Rivers
Incipient motion processes are reviewed for bed material in gravel-bed rivers. Prediction difficulties are identified. Research results are reported for field and flume studies to investigate...
Sediment Budgets in Gravel Bed Streams
A sediment budget/mass balance technique is presented for use in assessment of sediment transport by river reach in gravel bed streams. Selection of appropriate gravel bed transport equations,...
Bed Sediments Size Changes, Atchafalaya River
During low flows of 1989 and 1991, we collected bed sediment samples from the thalwegs of the Mississippi River from Cairo, Illinois, to Head of Passes and along the Atchafalaya River...
A Study of Lateral Bed Slopes Developed at Bend
A study was conducted to compare seven actual cross section profiles of Philip Bayou Realignment with the lateral bed slopes estimated from the model derived by Ikeda titled `Sediment...
Effect of Grain Size on Sediment Transport Calculations
The U.S. Army Corps of Engineers is currently developing a `Hydraulic Design Package for Flood Control Channels' (SAM). SAM is capable of computing sediment rating curves and stable channel...
Top Width of Pier Scour Holes in Free and Pressure Flow
The maximum top width of the local scour holes at piers is shown to be a simple function of the scour depth and the angle of repose of the bed material in water. Knowledge of the top width...
Operational and Structural Optimisation of Hydraulic Structures for Light Liquid Removal
The removal efficiency of light liquid separation schemes is determined by the hydraulic inflow conditions, the inflow fluid properties and the separator hydraulics. The relating set of...
Observations of Artificial Destratification
Artificial destratification using bubble plumes is one means whereby low dissolved oxygen in the hypolimnion of lakes and reservoirs may be averted. Temperature and DO were measured at...
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