Relationships between hydraulic parameters in a small stream under varying flow and seasonal conditions
✍ Scribed by D. R. Hart; P. J. Mulholland; E. R. Marzolf; D. L. Deangelis; S. P. Hendricks
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 198 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0885-6087
No coin nor oath required. For personal study only.
✦ Synopsis
Twenty conservative tracer injections were carried out in the same reach of a small woodland stream in order to determine how variation in discharge and leaf accumulation aect stream hydraulic parameters. The injections were made at various discharge rates ranging from 2 . 6 to 40 l/s. Five of the injections were made during late autumn, when there were large accumulations of leaves in the stream. Estimates of hydraulic parameters were made by ®tting a transient storage solute transport model to conservative tracer concentration pro®les. Velocity increased almost linearly with increasing discharge, indicating a decline in the Darcy friction factor. Dispersion also increased with increasing discharge, especially for the lower ¯ow injections. The relative size of the storage zone was small ($0 . 1). There was no de®nable relationship between discharge and the relative storage zone size, but the rates of exchange between the storage zone and the main channel increased markedly with increasing discharge. The presence of large accumulations of leaves had a clear eect on the hydraulic characteristics of the stream, producing much higher friction factors, larger storage zone sizes and lower velocity than would have been predicted by discharge alone.