Modeling Irrigation and Nitrogen Management
Irrigation increases the potential for nitrate accumulation in the groundwater in two ways. It increases the water content in the root zone creating a greater potential for leaching. Two...
Visual Estimates of Flume and Weir Operating Conditions
Laboratory studies were conducted on a rectangular broad-crested weir to determine the effects of entrance and exit conditions on the prediction of discharge and required energy loss....
Crop Irrigation Requirement Model for Utah
Crop irrigation requirements vary greatly across Utah's wide range of climatic conditions. About 40 electronic weather stations have been established in areas representing...
Stable Channels with Loose Boundary
Recently, G. Parker suggested that the lateral transport of downstream momentum due to Reynolds stresses should be included in the momentum balance used to calculate the boundary shear...
Power Formula for Open-Channel Flow Resistance
This paper evaluates various power formulas for flow resistance in open channels. Unlike the logarithmic resistance equation that can be theoretically derived either from Prandtl's...
Closed-Loop Control for Hydraulic Laboratory Operation
The implementation of Closed-Loop Feedback Control in the Bureau of Reclamation's Hydraulic Laboratory flow delivery system has provided an important new modeling tool for...
Applications of GSTARS Model
GSTARS is a Generalized Stream Tube model for Alluvial River Simulation. Depending on an engineer's need, GSTARS can be used as a fixed boundary as well as a movable boundary...
Two-Dimensional Numerical Modeling for Long-Term Sedimentation
Numerical modeling of long-term sedimentation processes in multi-dimensional models is computationally intensive and thus often uneconomical. A statistical superposition technique has...
Mathematical Modeling of Compound Channel with High Sediment Concentration
The mathematical model for erodible channels, FLUVIAL-12, has been extended to simulate the fluvial processes in the lower reach of the Yellow River in China. Fluvial processes in the...
Geotechnical and Hydraulic Stability Numbers for Channel Rehabilitation: Part I, the Approach
A model of incised channel evolution was developed to integrate the geotechnical and hydraulic factors that are involved in channel rehabilitation. Bank stability is attained when the...
Riverbank Instability Due to Bed Degradation
Degradation lowers the bed of an alluvial channel over a long reach. This has the effect of increasing the bank heights and angles, which decreases the stability of the banks with respect...
Computations of High-Velocity Flows on Alluvial Fans
The results of numerical models of supercritical flows on alluvial fans demonstrate the strong effect fan topography has on flow velocity and depth. Particularly important are transverse...
Features of Flow in Slurry-Thickening Ponds
The study reported was undertaken to investigate the physical processes which come into play in settling-pond slurry thickeners and causes their behavior to deviate from those included...
Microstructure of Cohesive Sediment Suspensions
In a shear flow field suspended fine sediments under relatively low concentrations and stable stratification conditions develop a step-wise profile. This is due to internal wave instability...
Near-Bed Sediment Concentration in Non-Uniform Flows Over Gravel Beds
The calculation of near-bed sediment concentration is formulated in terms of equations governing the dispersion of heavy particles in non-uniform turbulent shear flows over stable gravel...
Analytical and Numerical Modeling at High Sediment Concentrations
Methods for classifying sediment-water mixtures according to material concentration and rheologic properties are discussed. Results from laboratory and field measurements show that bed...
Three-Dimensional Modeling of Cohesive Sediments and Pollutants in Surface Waters
Particulate and dissolved pollutant transport rates are predicted using a pollutant transport modeling system. The latter is a finite element model capable of simulating three-dimensional...
Probabilistic Approach to Maintenance Scheduling
Maintenance has the purpose of prolonging the working life of equipment and of sustaining expected levels of performance and reliability. If equipment deterioration is construed as a probabilistic...
Entrainment of Bed Sediment by Density Underflows
The erosion caused by a density-driven underflow has been studied experimentally. The observations indicate that a strong density current can entrain substantial amounts of bed sediment....
Overview o New England Coastal Flood Study Methodology
This paper presents an overview of the development of methologies used to determine the probabilistic flood levels for New England coastal flood insurance studies. The Federal Insurance...
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