Low flow hydraulics in alluvial channels

Miller, Barbara A.; Wenzel, Harry G.

Permalink

https://hdl.handle.net/2142/90126 Copy

Description

Title

Low flow hydraulics in alluvial channels

Author(s)

• Miller, Barbara A.
• Wenzel, Harry G.

Contributor(s)

University of Illinois at Urbana-Champaign

Issue Date

1984-09

Keyword(s)

• Water resources center
• Water resources center--Illinois
• Hydrology and hydraulics
• Steady flow
• Streamflow
• Surface flow
• Nonuniform flow
• Varied flow
• Alluvial channels
• Alluvial rivers
• Hydraulic models
• Computer models
• Mathematical models
• Pools and riffles
• Low flow
• Open-channel flow
• River flow

Geographic Coverage

Illinois (state)

Abstract

The investigation of the low flow condition has become important in recent years as a means of determining critical levels of water pollution, aquatic habitat and instream flow needs. To assess these critical conditions, it is necessary to predict the hydraulic response of a river system to a given low flow discharge. Conventional flow models, however, are often inaccurate at low discharges due to the geometric and hydraulic channel features peculiar to these flow conditions. The dominant channel feature at low stages is the pool-riffle sequence, where pools are distinguished by deep, slow moving water and riffles by shallow, relatively rapid moving flow. Conventional flow models have difficulty effectively representing the highly nonprismatic channel geometry, the rapidly changing flow hydraulics, and the dominating influence of flow resistance characteristic of pool-riffle sequences. In this research, a one-dimensional mathematical model has been developed to simulate accurately channel characteristics under low flow conditions. For a given steady discharge, channel geometry, and channel bed particle size distribution, the model predicts the flow depth, the mean velocity, and the flow resistance. Energy losses are assumed to result from flow resistance, as well as from local losses generated by the contractions and expansions occurring through the pool-riffle sequence. The model has been verified using field data, as well as laboratory data collected in conjunction with the project.

Publisher

University of Illinois at Urbana-Champaign. Water Resources Center

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/90126

Sponsor(s)/Grant Number(s)

• U.S. Department of the Interior
• U.S. Geological Survey

Copyright and License Information

Copyright 1984 held by Barbara A. Miller, Harry G. Wenzel

Owning Collections