Articles | Volume 9, issue 6
© Author(s) 2021. This work is distributed underthe Creative Commons Attribution 4.0 License.
Temporal changes in the debris flow threshold under the effects of ground freezing and sediment storage on Mt. Fuji
- Final revised paper (published on 02 Nov 2021)
- Preprint (discussion started on 26 May 2021)
Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor |
: Report abuse
RC1: 'Comment on esurf-2021-41', Anonymous Referee #1, 22 Jun 2021
- AC1: 'Reply on RC1', Fumitoshi Imaizumi, 01 Jul 2021
- RC2: 'Comment on esurf-2021-41', Francis Rengers, 30 Jul 2021
Peer review completion
AR: Author's response | RR: Referee report | ED: Editor decision
AR by Fumitoshi Imaizumi on behalf of the Authors (25 Aug 2021)  Author's response Author's tracked changes Manuscript
ED: Referee Nomination & Report Request started (13 Sep 2021) by Jens Turowski
RR by Anonymous Referee #1 (20 Sep 2021)
RR by Francis Rengers (23 Sep 2021)
ED: Publish subject to minor revisions (review by editor) (24 Sep 2021) by Jens Turowski
AR by Fumitoshi Imaizumi on behalf of the Authors (04 Oct 2021)  Author's response Author's tracked changes Manuscript
ED: Publish as is (07 Oct 2021) by Jens Turowski
ED: Publish as is (08 Oct 2021) by Andreas Lang(Editor)
The manuscript (MS) deals with the role of (a) ground freezing and (b) sediment storage in debris-flow triggering and how rainfall thresholds are affected. Relatively long records (~50 years) of debris-flow observations in a Japanese gully are combined with ground-freezing periods estimated from a model, and sediment storage volumes estimated from LiDAR measurements or aerial photographs. While the role of sediment storage was less revealing, the authors found ground freezing to alter rainfall thresholds significantly and explain it with different infiltration rates depending on if the ground is frozen or unfrozen. The MS discusses an important topic with possible impacts both on the development of early warning systems and climate change impact assessments in cold debris-flow prone regions.
The MS is generally well written and structured. The data sets provide a good basis for the research on the influence of climate on debris-flow activity. The author’s approach in estimating ground-freezing periods and connecting it to debris-flow triggering is original and promising. However, the analysis and discussion on other potential reasons for differences in rainfall thresholds are missing and therefore I had difficulties in believing the findings. The main reasons concern the following:
These points would need to be clarified in order to convincingly show the relevance of ground freezing on debris-flow triggering. Then I see it as a very valuable contribution to Esurf. Furthermore, there were some unclarities in the methods and the data sets used. Further comments related to this and other minor issues are listed below.
Although you cite the equations, it would be helpful if you would state the assumptions behind it. Is this the degree-day method you mention before? The meaning of cf and cm are not clear to me.