Fig. 4
From: River-bed armouring as a granular segregation phenomenon
Armour thickness and segregation flux through time. a Temporal evolution of the thickness of the armored layer at different Shields number. Legend indicates Shields number associated with each curve, and applies to b, c also. The brighter continuous lines are predictions from the advection-diffusion model, Eq. (2). Note the first rapid stage of armouring, which is dependent on Shields number and is associated with bed-load transport, and the second slower stage that exhibits a nearly constant rate for all Shields numbers and is the result of creep. b The variation of segregation flux density (J/A) with time. c Normalized flux against dimensionless time; data are reasonably collapsed
