Density stratification in the Yellow River, China

I recently submitted another dissertation chapter for publication, this one titled “Suspended-sediment induced stratification inferred from concentration and velocity profile measurements in the lower Yellow River, China”.

The study examines the vertical structure of velocity and concentration profiles in the Yellow River. In particular, we examine how the addition of sediment modulates the turbulent kinetic energy budget of the flow. The addition of sediment to the flow (in this case in very high concentrations) causes the flow to become stratified, and inhibits vertical mixing.

When you break down the stratification by sediment grain sizes, we found that the smallest grain size classes <25 um additionally extract momentum from the flow. This was surprising, since conventional notion dictates that this sediment would be uniformly stratified and behave as “washload”.

Stratification adjustment coefficient α measured in the Yellow River, China. Values of α<1 imply a density stratification effect. Panel a) total concentration profile adjustment. Panel b) grain-size specific adjustment to the concentration profiles.

Look out for the study in Water Resources Research!