EVEN RIFFLE-POOL RATIOThe article reports that a perfect stream for fishing will have one pool for every section of riffle.Field & Stream
Riffle habitats were characterised by slopes greater than 0.0099 and run and pool habitats by lesser slopes. Simple classification rules, based on water surface slope and either velocity/depth ratio or Froude number, correctly classified 6566% of the habitats. Froude number and velocity/depth ratio ...
Pool depth, length, and volume tend to increase with larger drainage area and decrease with more sediment supply. Few details of controls on riffle geometry are presently known. The sequences eventually create stage-dependent form resistance with higher forces in pools at high flow and sediment-...
The effective width tends to equalize again with a ratio of 1:1 between the pool and riffle during a modeled discharge of a five-year flood, as the large roughness elements above the pool become drowned out. Results suggest that forced pool–riffle sequences in boulder-bed streams are ...
Results show that reversal depends critically on the ratio of riffle-to-pool width, residual pool depth (difference between pool and riffle elevations) and on the depth of flow over the riffle ( Chapter 2: A Unifying Criterion for the Velocity Reversal Hypothesis in Gravel-Bed Rivers).;In ...
The average width and depth ratio of the pool is 7.74 which vary from 4 to 12.5. The average spacing of the pool is calculated about 1.4km. The channel width at riffle is significantly greater than that at the pool. The trend of the regression line shows that there is a negative ...
Our experiments produce pool‐riffle like structures across average Shields stresses τ? that are a factor 1.5–2 above the threshold mobility condition of the experimental grain size distribution. Local topographic responses are coupled to channel width changes, which drive flows to accelerate or ...
This study investigates the distributions of velocity and Reynolds stress in an artificial pool-riffle sequence for two entrance slopes of 5掳 and 20掳 in a laboratory and compares the results with a similar pool-riffle sequence in a gravel-bed river in central Iran. Quadrant analys...
ANCOVA with stepwise model selection indicated that degree of land-use (categorical), bankfull spacing of pools, upstream riffle slope and expansion ratio were all significant ( 伪 = 0.1) predictors of volume of pools ( R 2 = 0.73). Simple linear regression of mean volume of pools and ...
In this paper we investigate whether the bar instability forming alternate bars also contributes to PRS formation, periodicity and maintenance. This was unclear because bar instability occurs only when the ratio of channel width/depth exceeds a critical value, generally understood to be approximately ...