Flow Rates

• From visual observances, three modes of particle transport due to flow rates were identified.
• At low flow rates, particles build up against the riffle until it becomes full, and then roll/slide into the next riffle spacing.
• At moderate flow rates, erosion by turbulence increases, and reduces the amount of material held in the riffle.
• At high rates most of the material is carried downstream, leaving only “dead zones” in the corner