Short communication: Multiscalar roughness length decomposition in fluvial systems using a transform-roughness correlation (TRC) approach

Adams, David L.; Zampiron, Andrea

doi:https://doi.org/10.5194/esurf-8-1039-2020

Articles | Volume 8, issue 4

https://doi.org/10.5194/esurf-8-1039-2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/esurf-8-1039-2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 8, issue 4

Short communication

|

09 Dec 2020

Short communication |

| 09 Dec 2020

Short communication: Multiscalar roughness length decomposition in fluvial systems using a transform-roughness correlation (TRC) approach

David L. Adams and Andrea Zampiron

Download

Final revised paper (published on 09 Dec 2020)
Preprint (discussion started on 20 Jul 2020)

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

- Printer-friendly version

- Supplement

RC1: 'Review', Anonymous Referee #1, 30 Jul 2020
- AC1: 'Reviewer 1 final response', David Adams, 27 Aug 2020
RC2: 'Interactive comment on "Short communication: Multiscalar drag decomposition in fluvial systems using a transform-roughness correlation (TRC) approach" by David L. Adams and Andrea Zampiron', Anonymous Referee #2, 17 Aug 2020
- AC2: 'Reviewer 2 final response', David Adams, 27 Aug 2020

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

AR by David Adams on behalf of the Authors (07 Sep 2020) Author's response Manuscript

ED: Referee Nomination & Report Request started (24 Sep 2020) by Jens Turowski

RR by Anonymous Referee #1 (05 Oct 2020)

RR by Anonymous Referee #2 (07 Oct 2020)

Suggestions for revision or reasons for rejection

General comments:

This is a revised version of the manuscript that describes and discusses a potentially useful new technique to assess flow resistance in natural channels and particularly in gravel-bed streams. The novel method proposes to estimate the relative contribution of different physical scales of river bed topography to the total drag. To do so, a transform-roughness correlation (TRC) approach is used, based on a wavelet transform and a correlation of different elements of the bed structure with a roughness metric. The approach is applied to two different sets of flume experiments, one reproducing a pool-riffle morphology and the other a step-pool morphology.

In my view, the authors have sufficiently addressed the reviewers’ comments, both in their reply and in the revised manuscript.

I have only one more general comment with regard to Figure 4. It appears that there is an approximately linear relationship between the two roughness length estimates (k*s,cw and k*s,rc) for the step-pool data. For the plane-bed data, one could claim that k*s,cw is roughly constant on average while k*s,rc varies over a larger range. For the pool-bar-riffle data there is a somewhat opposite trend, one could claim that k*s,rc is roughly constant on average while k*s,cw varies over a larger range. Can the authors speculate about possible reasons for these three different trends?

Specific comments:

L135: “LAS” needs to be defined.

L226: Replace “the results the supports the application” by “the results support the application”

L230: Maybe replace “explained by” by “associated with” (the statement does not really include an explanation)

L248: “… estimates of ks are positively correlated with an approximately linear relationship (Figure 5). Not clear what you mean since you refer to a log-log plot. In the strict sense there is an approximately linear relationship for the HW-data and for the A-BES data for log(k*s,rc) > -4.6, however the remaining A-BES data would rather follow a power-law relation.

L267: downwards

Hide

ED: Publish subject to technical corrections (16 Oct 2020) by Jens Turowski

ED: Publish subject to technical corrections (16 Oct 2020) by Tom Coulthard (Editor)

AR by David Adams on behalf of the Authors (22 Oct 2020) Manuscript

Post-review adjustments

AA: Author's adjustment | EA: Editor approval

AA by David Adams on behalf of the Authors (02 Dec 2020) Author's adjustment Manuscript

EA: Adjustments approved (07 Dec 2020) by Jens Turowski

Short summary

This paper presents a novel method of estimating the relative contribution of different physical scales of river bed topography to the total roughness length, based on thalweg elevation profiles. By providing more detailed information regarding the interaction between surface topography and fluid dynamics, the proposed technique may contribute to advances in hydraulics, channel morphodynamics, and bedload transport. Also, it may provide alternatives to existing representative roughness metrics.