A Coupled GIS-Water Quality Modeling System
A modeling framework is developed which uses a geographic information system (GIS) to perform many of the time-consuming tasks needed to set up and run a general water quality model. The...
Predictability and Sensitivity of Groundwater Transport Models
The uncertainty associated with predictions made by solute transport models in groundwater environments must be carefully evaluated to address spatial and time variability as well as data...
Movement of Colloids Under Hydraulic Gradients
A model was developed for analyzing the movement of colloidal clay particles in laboratory soil columns. The physical mechanisms of detachment of particles from the soil matrix, their...
Effect of Data Sampling Time Resolution on Probability Distribution of Elapsed Time Between Rainfalls
The elapsed time between rainfalls is useful information in statistical forecasting of rainfall and runoff. The probability density function (pdf) of the elapsed time can be determined...
Real-Time Flood Forecasting Using Adaptive Estimation
The proposed flood forecasting system combines a flood routing model with a parameter estimation model. The flood routing model utilizes ?-index to determine the effective rainfall and...
Long Term Predictability of River Stages under ENSO Influence
The paper explores the bases for alternative approaches to river flow and hydrologic time series forecasting. The precipitation that forces river flow contains significant modes of variability...
HEC River Analysis System (HEC-RAS)
The Hydrologic Engineering Center (HEC) is developing next generation software for one-dimensional river hydraulics. The HEC-RAS River Analysis System (HEC, 1994) is intended to be the...
Nonlinear Hydrodynamic Pressures on Arch Dam Faces
A finite difference method was used to calculate the nonlinear hydrodynamic pressures on the rigid arch dam faces. The arbitrary reservoir shapes were transformed to a regular cubic by...
Estimation of Spillway Free Jet Trajectory Lengths
The design of high head spillways with flip bucket terminal structures must include analysis of the length of the free jet issuing from the spillway. Prototype jet trajectory lengths are...
Influence of a Sand Layer on Headcut Advance
The presence of an erodible material layer in the soil profile has been observed to influence headcut movement in earth emergency spillways. Large-scale flume tests were conducted to examine...
What is Computational Hydraulics?
Computational hydraulics deals with methods and techniques for the numerical simulation of water flows in natural or man-made systems with the aid of computers. Flow and transport modeling...
A Lagrangian Model for Surface Buoyant Jets
A model is developed to predict the trajectory of a surface buoyant discharge into a large receiving water body. A Lagrangian approach is used to trace the path of a `control volume' of...
Improved Hydraulic Features of the HEC River Analysis (HEC-RAS)
The Hydrologic Engineering Center (HEC) is in the process of developing a Next Generation (NexGen) of hydrologic engineering software. The goal in the area of river hydraulics is to develop...
Energy Dissipation for a RCC Stepped Spillway
A two-dimensional physical model study was used to quantify the kinetic energy dissipation of the steps in a roller compacted concrete (RCC) stepped spillway. The steps were effective...
One- and Two-Dimensional Analysis of Flow in Hotophia Creek, MS
A numerical experiment on the influence of a sand bar encroachment on the stream flow pattern is reported. The results of a two-dimensional analysis were compared with results of an equivalent...
Climatic Perspective on the 1993 Mississippi R. Flood
The 1993 summer flooding in the Upper Mississippi River Basin was the most devastating flood of modern times with damage estimates in the range of 15-20 billion dollars. The paper describes...
1993 Mississippi Record Stages and Levee Failures
Record-setting stages, flooding duration, and multiple levee failures are distinguishing features of the Mississippi River 1993 flood. The peak stages reached at stations along the Illinois...
Impacts of the 1993 Flood on the Mississippi River in Illinois
The 1993 flood has now been recognized as one of the greatest floods on the Mississippi and Missouri Rivers. Its geographical extent included portions of Iowa, Missouri, Illinois, Wisconsin,...
Design of Manning's-Rougness-Coefficient Study in New York State
Field-collected hydraulic data can be used to compute roughness coefficients for channels with different hydraulic characteristics. Suggested criteria for the design of a roughness-coefficient...
Bias in Regression Estimates of Manning's n
Selected equations for estimating roughness for gravel-bed streams were tested using a composite data set containing much of the data used to define the equations. All equations tested...
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