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Location and Planform
The hydraulics were analyzed on the Logan River just below it's confluence with Temple Fork.
Field notebook showing reach location &
channel planform of reach
Google Earth identification of reach and flow features
Oblique Photos and Videos of Flow Features
Convergent Flow
Divergent Flow
Uniform Flow
Flow Seam
This flow seam is caused by the converging of flows of varying magnitudes
Shear Zone Types
Wake
Eddy (I didn't take a picture of the one indicated in the planform sketch, this one is slightly downstream and is indicated on the Google Earth Imagery)
Surface Flow Types
Glide near the channel edge
A run where uniform flow was observed, where the flow path was deeper and at higher velocity
Riffles were present in shallower areas where flow was more spread out across the channel
Cross Section and Discharge
Discharge was estimated using a mandarin peel
The peel traveled roughly 11meters
in roughly 11 seconds
11m / 11s = 1 m/s
Distance / Time = Velocity
The river depth was estimated to be 0.5 m in the thalweg and 0 m at the banks, so the average depth was estimated to be 0.25 m. The width of the channel was estimated to be 6 m. These measurements are indicated in the cross section sketch.
Field sketch of the channel cross section (facing downstream)
(0.5m + 0 m )/2 = 0.25m
(Thalweg depth + Bank depth) averaged = average depth
6m * 0.25m = 1.5 m^2
width * depth = area
The cross-sectional area was then applied to the observed velocity to calculate discharge.
1.5 m^2 * 1 m/s = 1.5 m/s^3
area * velocity = discharge
Hydraulic Jump
Overview of hydraulic jump from upstream to downstream
A stick traveling through the hydraulic jump
0s- Upstream subcritical flow
0.5s- Transition to supercritical flow
1s- Hydraulic jump (stick is submerged)
2s- Downstream subcritical flow
Anatomy of a hydraulic jump
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