Investigation of Chloroform Plumes in a Porous Media
A sand box model was used in the laboratory to study the development and stability of the contaminant plume with respect to space and time. Steady, uniform flow velocities were established...
Flow and Transport of Nonaqueous Phase Liquids in Groundwater Systems
Nonaqueous phase liquids (NAPLs) are present at numerous hazardous waste sites and are suspected to exist at many more. Due to the numerous variables influencing NAPL transport and fate...
Verification Tests for Transport Modeling in Coastal Aquifers
The U.S. Geological Survey three dimensional Heat and Solute Transport (HST3D) model is used to simulate fate and transport of dissolved contaminant in coastal aquifers. The model originally...
Polyacrylamide Decreases Furrow Erosion
Erosion from furrow irrigated land is a serious problem in southern Idaho and several other areas. Polyacrylamide, a very long chain polymer, increases aggregate stability and flocculates...
Evaluating and Guiding Weather Modification Efforts with Advanced Three-Dimensional Numerical Models
Several recent developments have expanded our capabilities to understand and document precipitation processes. One of these developments is the recent advances in computer hardware and...
A New Look at the Potential of Hygroscopic Seeding in Summertime Convective Clouds
Hygroscopic seeding was conducted in the sixties and early seventies in the USA, but since then, most cloud seeding efforts have used glaciogenic seeding materials, usually silver iodide...
Stable Slopes of Alluvial Channels
An alluvial channel responds to the variation in the incoming sediment by changing its cross-section and especially the slope. Regime relations formulated by Lacey (1930) and many subsequent...
Computing in Civil and Building Engineering
This proceeding consists of papers presented at the Fifth International Conference on Computing in Civil and Building Engineering held in Anaheim, California, June 7-9, 1993. The proceedings...
Parameter Estimates for a Groundwater Model
This paper presents a parameter sensitivity study of a two dimensional flow and transport model of a contaminated site. Hydrogeological and site data from previous investigations were...
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...
Surface Flows Over Intertidal Marshes
A marsh-flow measuring device has been designed to quantify the flow across the marsh surface. The fluorometric technique by tracking the visible substance (Rhodamine red dye) applied...
Current Legal Issues in Sedimentation
This paper represents the updating of Chapter 7 for Manual 54. There has been considerable change in legal rulings and precedent law since the first edition of Manual 54. Many of these...
Updating Chapter II?Sediment Transportation Mechanics
Chapter II, the most comprehensive chapter of the Sedimentation Engineering Manual, has aged. The manual prepared by the Task Committee for the Manual on Sedimentation was published by...
Scour Analysis at Highway Structures
ASCE Manual 54 entitled, `Sedimentation Engineering' is being revised. In the revision, a chapter on `Scour at Highway Bridges' will be included. This paper will describe in general terms...
Modeling the Fate and Transport of Toxic Heavy Metals in South San Francisco Bay
A two-dimensional vertically-averaged finite element model for the fate and transport of cohesive sediments and associated toxic heavy metals was utilized to predict the spatial and temporal...
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,...
Extreme Events and Coastal Wetlands
Temporal ecosystem behavior in tidal wetlands can be static, dynamically stable, progressively changing, or subject to catastrophic change during extreme events. Catastrophic change in...
Weaver Bottoms Backwater Rehabilitation
Navigation channel dredge material was used to construct closure structures and islands in lower pool 5 on the Upper Mississippi River in 1986. Primary objectives included aquatic habitat...
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...
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