Relationships Between Flow and Benthic Communities
Current flows can affect directly factors critical to the survival of benthic communities, including the availability of food and nutrients, the chemical quality of water surrounding benthic...

Emergency Action Plan
Although most dam owners have a high level of confidence in the structures they own and are certain their dams will not fail, the Bureau of Reclamation (Reclamation) included, history...

U.S. Geological Survey Bedload Sampling Policy
During the late 1960's, the U.S. Geological Survey's (USGS) Water Resources Division (WRD) developed the Helley-Smith bedload sampler. Since then, the USGS and the Technical Committee...

A Model of Mixing in a Stratified Tidal Flow
We will describe a simple model of vertical mixing in a stratified tidal flow that might be observed in shallow estuary like San Francisco Bay. The model flow is driven by a specified...

Yolo Bypass Wetlands?Impact Investigation
Approximately 20 square kilometers of wetland facilities are proposed to be installed within the Yolo Bypass of the Sacramento River Flood Control Project. A hydraulic impact investigation...

Plans for a Sensitivity Analysis of Bridge-Scour Computations
Plans for an analysis of the sensitivity of Level 2 bridge-scour computations are described. Cross-section data from 15 bridge sites in Texas are modified to reflect four levels of field...

Computational Hydraulics?The Systems Approach
This paper introduces two modern computational hydraulic computer programs that combine the calculated subcritical and supercritical water surface profiles and pressure gradients in open...

Water Surface Profile Computations?How Many Sections do I Need?
One-dimensional streamflow models, including standard-step models, require a sufficient number of cross sections to satisfy two needs. First, a sufficient number of cross sections must...

Predicting Water Quality at Municipal Water Intakes?Part I: Application to the Contra Costa Canal Intake
The factors affecting water quality at a municipal surface water intake in the Sacramento-San Joaquin Delta are discussed. A model is developed that successfully predicts the seawater...

Predicting Water Quality at Municipal Water Intakes Part 2: Application to the Southern Sacramento-San Joaquin Delta
Work in progress on developing methodologies for predicting water quality at Municipal intakes in the Sacramento-San Joaquin Delta is discussed. Principal sources of salinity are identified...

Simulating THM Precursors Transport with DWRDSM
A study was conducted by the California Department of Water Resources (DWR) to demonstrate the ability of its Delta Simulation Model (DWRDSM) to simulate fate and movement of inorganic...

Density Currents in Pollutant Transport and Mixing
A buoyant spreading model for the current-advected plume is formulated including several distinct mechanisms: convective spreading, interfacial friction spreading, entrainment at the density...

Criticality of Density Intrusions
Previous analyses of density intrusions indicates that a steady interface cannot be maintained if the front propagates at a speed greater than that of long interfacial waves. Supercritical...

Plunge-Pool Aeration Due to Inclined Jets
The present study quantifies how jet height and nozzle inclination angle and diameter affect the rate of air entrained by inclined circular jets. An air-collection hood and a vacuum pump...

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...

Nonuniform Transient Sediment Transport Modeling
A numerical model based on Lai's (1991) multimode scheme for fully coupled simulation of water and sediment movement in mobile-bed alluvial channels with nonuniform bed materials has been...

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...

Preliminary Studies of Pressure Flow Scour
Bridges that become inundated during floods have slightly pressurized flow that impacts bridge piers and creates an aggravated scour condition. Results of two preliminary laboratory studies...

 

 

 

 

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