The velocity-reversal hypothesis revisited

Autor: Douglas M. Thompson
Rok vydání: 2010
Předmět:
Zdroj: Progress in Physical Geography: Earth and Environment. 35:123-132
ISSN: 1477-0296
0309-1333
Popis: In 1971, Edward Keller proposed the velocity-reversal hypothesis to describe observations where near-bed velocities in pools increased at a faster rate than in riffles. The reversal in conditions was used to explain the maintenance of pool-riffle sequences. The hypothesis continues to draw interest, and research shows that velocity reversals occur in limited conditions, but average cross-sectional velocities in pools do not universally exceed those in riffles at near-bankfull flows. A consensus is now beginning to form that flow convergence in pools is common at high flow and helps to form an isolated region of jet flow with high velocities that maintains the characteristics of the pool-riffle sequence.
Databáze: OpenAIRE