Northwestern Clay Sand Laboratory Experiments Phase 1


Authors:
Owners:
Resource type: Composite Resource
Storage: The size of this resource is 90.3 MB
Created: Apr 29, 2020 at 10:55 p.m.
Last updated: Apr 30, 2020 at 3:45 p.m.
DOI: 10.4211/hs.0983ec823ac64088b25882a6e99341ab
Citation: See how to cite this resource
Sharing Status: Published
Views: 337
Downloads: 14
+1 Votes: Be the first one to 
 this.
Comments: No comments (yet)

Abstract

Fine particles (0.1-100 microns) are ubiquitous within the water column.
Observations on the interactions between suspended fine particles and sediment beds remain limited, reducing our ability to understand the interactions and feedbacks between fine particles, morphodynamics and hyporheic flow.
We performed laboratory experiments to explore changes in bedform morphodynamics and hyporheic flow following the progressive addition of kaolinite clay to the water column above a mobile sand bed.
We characterized these interactions by taking high-frequency time series measurements of bed topography and freestream clay concentration combined with solute injections and bed sediment cores to characterize subsurface properties.
Deposition of initially suspended clay resulted in a decrease of bedform height, celerity and sediment flux by 14%, 22% and 29% when 1000g was accumulated within the bed (equal to clay/sand mass ratio of 0.4\% in the bed).
The hyporheic exchange flux decreased by almost a factor of 2 for all clay additions, regardless of the amount of clay eventually deposited in the bed.
Post experiment sediment cores showed clay accumulation within and below the mobile layer of the bedforms, with the peak concentration occurring at the most frequent bedform scour depth.
These results demonstrate the tight coupling between bed sediment morphodynamics, fine particle (clay) deposition, and hyporheic exchange.
Suspended and bed load transport rates are diminished by the transfer of suspended load to the sediment via hyporheic exchange. This coupling should be considered when estimating sediment transport rates.

Subject Keywords

Resource Level Coverage

Temporal

Start Date:
End Date:

Content

How to Cite

Dallmann, J. (2020). Northwestern Clay Sand Laboratory Experiments Phase 1, HydroShare, https://doi.org/10.4211/hs.0983ec823ac64088b25882a6e99341ab

This resource is shared under the Creative Commons Attribution CC BY.

 http://creativecommons.org/licenses/by/4.0/
CC-BY

Comments

There are currently no comments

New Comment

required