A High-Resolution, Random Forest Approach to Mapping Depth-to-Bedrock across Shallow Overburden and Post-Glacial Terrain

Round 1

Reviewer 1 Report

General Comment:

This study presented the high resolution DTB model by focusing on the New Brunswick, Canada. The authors provided an understanding of regolith thickness across a post-glacial terrain. I’ve made some comments to develop this manuscript. Also, I would like to very strongly recommend that the authors improve English in the entire manuscript to provide a clear idea for the study. Overall, I reject the manuscript for publication at this time.

Specific Comments:

1. In Title, please change the title expressing the purpose of the study and the new methodology which you applied for.
2. In Abstract, please clearly provide the objective, the methodology, and the main result of this study.
3. In Line 19 on Page 1, please add a dot at the end of the text.
4. In Line 22-25 on Page 1, I could not understand the text of “ LiDAR derived topo-hydrological and surficial geological attributes were developed as predictor variables as inputs for a Random Forest model, where DTB measurements were split 70:30 for model development and validation, respectively.” Please rewrite it.
5. In Line 47 on Page 2, why did you use the bold word of “consolidated” in the text?
6. In Line 89 on Page 3, you already defined “RK” in Line 83. Please use “RK” if you abbreviate a word.
7. In Line 101 on Page 3, what is “kyr”?
8. In Introduction, please write the issues related to this research and the objectives for the present work.
9. In Line 119 on Page 3, what is “k ybp”?
10. In Figure 3, please add the title of the x-axis in A, B, C, and D.
11. In Line 279 on Page 8, please provide a scree plot to identify how to determine the number of PCs. How about 100% and 95% PCs?
12. In Line 323 on Page 9, why did you use 10 folds? You can consider 7 folds, 5 folds, and Jackknife cross validations.
13. In Result, the results section seems to be too short.
14. In Discussion, the 4.1 section may be moved to the Results section.
15. In Line 346-347 on Page 10, please add equations for the statistical indices in the section 2.6.
16. In Conclusion, the conclusion section tends to be too short. Please extend the section including the objectives, results, discussion, and future works.

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report

Fig.3. - Please explain what does the red line represent.

Lines 212 - 216. The abbreviations do not correspond to those in Fig. 4

Chapter 2.5 Please explain all the abbreviations in the text. Not just in the discussion. Without that it is hard to follow the paper.  

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 3 Report

The manuscript “A remote sensing approach to high resolution, landscape-scale, depth-to-bedrock mapping in shallow overburden, post-glacial landscapes” present the high-resolution DTB model based on publicly available data including DEM, boreholes data etc. I believe that used approach and received results are valuable for future studies in DTB mapping and application in other research areas such as soil science, ecology, land use managment etc. The manuscript is well-written and well-structured with good and clearly presented figures and tables. I would consider it to publish in Remote Sensing after a minor revision. My general comments are:

1. The meaning of "post-glacial landscapes" term used in manuscript corresponds to glacial or fluvioglacial landscapes, as the relief features were formed during the glacial time and New Brunswick region is such area. While "post-glacial" means that relief was formed after the glacial time. Please correct this or provide the clear definition.  
2. What is the specific of glacial landscapes in context of regolith thickness study? Why was NB region chosen?
3. When you use active referencing, write a full name instead of number, like Wile et al. [1] (e.g. line 71 [5], line 73 [13], line 74 [2], line 76 [4], line 77 [14], etc (you can read more https://www.slu.se/en/subweb/library/write-and-cite/writing-references/in-text-citations-using-the-harvard-system/).
4. Unfortunately, appendix figure A1 and especially Table S1 were not provided therefore the meaning of some using model parameters were not clear.

Detailed comments and suggestions are listed below:

3 I think it is better to add the name of study region, New Brunswick, Canada

Abstract

19 Missing point between sentences

21 with depth range...

25 MAE and RMSE abbreviations better to write fully

Introduction

55-56 What is the difference between surface and near-surface landscape forming processes?

56-66 The sentence about post-glacial landscapes lies between the general description of regolith. Better to start the  glacial landscapes topic after general description of the regolith.

Are there specific features of glacial landscapes regarding the DTB in comparison with other regolith landscapes?

102 climate warming in Holocene

Why you choose the methodology and post-glacial landscape in Canada - any local specific needs?

111-114 Here are the results, but should be the aim and objectives of study presented with suggested approach.

Methods

116  Study region

118 Better to use "geomorphologic features" instead of "surgical geologies"

118-120 "An array" is used twice in the sentence

121 Better to use "Deposits are represented by combination of..."

123 Figure 1b

127 Reference to Figure 1a should be added in the end of sentence

127-128 Better to write " in bedrock type and geomorphologic features... "

128 add DTB range

130 Add briefly the climate (annual, July, January air temperatures, precipitations)

 and landscape type (taiga etc) characteristics

131-134 Figure 1 - add coordinates and north arrow. In accordance to RS rules for authors "Images and maps must have a scale, a north arrow and coordinates" 

Colors of  fig 1b legend and the figure are quite different, they should be the same.

135  Regolith and DTB Data Source

137 Extra point after Figures.

138 Seems that also coordinates were used from sources at least. Other parameters?

170 Will be good to add names of sources to figures as well

173 Extra space in bore holes

173 Will be good also to add names of sources to figures

178-179 regarding DTBs and location?

202 airborne? LiDAR-derived 10 m DEM. By whom and when it was produced?

241 vector dataset of which parameters?

245-246 What is the source of water bodies and wetland boundaries?

248 What means "agg_dist" and "agg_10" data sets?

297 It is not clear exactly meaning of the " atmospheric exposure " - air temperatures, precipitation impact? From written below explanation it seems that you mean "slope or aspect exposure"?

Results

336 Better to write full name of parameters for good readeness and better understanding

343 What means terrain surface texture - roughness? How it was estimated?

354 Add in the figure also full name of parameters

356 Extra point

365 10m2 superscript is missed

Discussion

Please write the depths in m of DTB together with "shallow" or "deep" characteristics.

If there are literature data of DTB with similar model approach please add the comparison of results.

411 What means real surface area?

418 What means topographic negative openness?

434 What means sky view factors?

435 What means diurnal anistropic heating?

470-472 Add this information to study region chapter

Conclusion

501-502 Add briefly the general study information (study region, the area, the region specific - glacial landscapes, used approach and main results with accuracy assessment).

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

I do not think that the authors have addressed the all comments (ex. 13 and 14). So, I reject the manuscript for publication. However, if the editor wants to publish this paper in Remote Sensing, you could consider other reviewers and accept their opinion. 

Many thanks.

Author Response

Dear Reviewer

Thank you once again for reviewing our MS.  The main concerns are centred around (a) English and (b) the reporting of results.  

For context, all of the authors are native English speakers.  We have given this MS to other colleagues to read, and have not been informed of any language deficiencies.  With that, it is difficult to ascertain which part of the MS you find linguistically lacking. 

We stand by our initial statement relating to the reporting of results.  Results ought to be succinct, and the suggestion that discussion points should be added to the results section is not something we agree with.  Perhaps this is stylistic.  Regardless, we remain steadfast that we have reported the results concisely.

Aside from these comments, thank you once again for taking time to review our MS.  

Best to you and yours,
Antóin M. O'Sullivan

Reviewer 3 Report

Dear Authors,

Thank you for your revised work. I believe that the manuscript is enough improved for publishing in present form.

Good luck!

Author Response

Dear Reviewer

Thank you for taking time to once more reviewer our MS.  Your comments have strengthened this MS.  We are excited to have this MS published. 

Best to you and yours,

Antóin M. O'Sullivan