Hydro-sedimentological drivers of fine sediment ingress in a gravel-bed river

A - Papers appearing in refereed journals

Maltauro, R., Stone, M., Collins, A. L. and Krishnappan, B.G. 2024. Hydro-sedimentological drivers of fine sediment ingress in a gravel-bed river. Catena. 241 (108067). https://doi.org/10.1016/j.catena.2024.108067

AuthorsMaltauro, R., Stone, M., Collins, A. L. and Krishnappan, B.G.

Most studies investigating fine sediment ingress in gravel-bed rivers have been conducted at the laboratory scale,
and even fewer have explored the ingress processes of flocculated particles. Here, an extensive in-situ sampling
programme was undertaken to investigate hydro-sedimentological drivers of interstitial fine sediment accumulation and to evaluate fine sediment ingress directional mechanisms in a gravel-bed river located on the eastern
slopes of the Rocky Mountains in southern Alberta. Three sediment trap designs were installed across seven
deployment cycles at four sites along the river. Instantaneous discharge, suspended solids concentration, and
particle size distributions (of suspended and ingressed particles) were measured, while relevant hydraulic parameters were modelled with a flow model (MOBED). Distinct patterns of ingress dynamics between non-cohesive and cohesive fractions of fine sediment were observed. While the assessed hydro-sedimentological
parameters did not statistically explain the ingress rates of non-cohesive 0.5 – 2 mm particles, the opposite
was observed for < 0.5 mm particles, which were mostly transported in flocculated form. For flocculated
sediment, horizontal ingress accounted for ~ 60 % of interstitial accumulation. Directional ingress mechanisms,
however, were dependent on flow conditions for both particle size fractions, with vertical and horizontal accumulations becoming more important during higher and lower energy flows, respectively. Our observations
demonstrate the importance of ingress for the interstitial accumulation of fine sediment, even during events with
flow above the critical threshold conditions for fine sediment gravitational deposition. Despite the comparable
ingress rates to other studies, no interstitial clogging was observed in this study, demonstrating the channel
potential storage capacity, which has implications for legacy impacts from landscape disturbances in the
Crowsnest River catchment.

KeywordsCohesive sediment ; Fine sediment accumulation ; Infiltration mechanisms ; Legacy effects
Year of Publication2024
Journal citation241 (108067)
Digital Object Identifier (DOI)https://doi.org/10.1016/j.catena.2024.108067
Open accessPublished as ‘gold’ (paid) open access
FunderBiotechnology and Biological Sciences Research Council
Funder project or codeResilient Farming Futures (WP2): Detecting agroecosystem ‘resilience’ using novel data science methods
forWater NSERC Network for Forested Drinking Water Source Protection Technologies
NSERC Discovery Grant 481 RGPIN-2020- 06963
Publisher's version
Output statusPublished
Publication dates
PrintJun 2024
Publication process dates
Accepted26 Apr 2024
PublisherElsevier Science Bv

Permalink - https://repository.rothamsted.ac.uk/item/99026/hydro-sedimentological-drivers-of-fine-sediment-ingress-in-a-gravel-bed-river

20 total views
1 total downloads
20 views this month
1 downloads this month
Download files as zip