Review Reports - Terrain Representation and Distinguishing Ability of Roughness Algorithms Based on DEM with Different Resolutions

Round 1

Reviewer 1 Report

Most of the issues I suggested for the first version of the paper are being appropriately addressed in the revised one. I advise the paper should be published after some minor revisions mentioned below:

>> Line 16 : Fuyang, a 16 district of Hangzhou city with various landform types, is selected as the research area.

>> Line 17 to 19: Try to rephrase this sentence “and slope, root mean squared height, vector deviation, and two-dimension continuous wavelet transform are the parameters measured by these four typical roughness algorithms”

>> Line 19 and 20: The resolutions used are 5, 10, 19 25, and 50 m DEM for plain, hilly, and mountains areas.

>> Line 22 : The expression ability of the two algorithms => specify the two algorithms in the text

>> Line 47 : McKean and Roering, and Glenn and Booth carried

>> Line 51 : 10 kinds of algorithms

>> Line 59 to 74: the authors give a good understanding of the impact of spatial resolution on DEM quality. However, I advise to add the suggested references in the version 1 of this review, because these references contains recent, old and some fundamental research papers, which are :

Habib A, Khoshelham K, Akdim N, El Ghandour F, Labbassi K, Menenti M (2018) Impact of spatial resolution, interpolation and filtering algorithms on DEM accuracy for geomorphometric research: a case study from Sahel-Doukkala, Morocco. Modeling Earth Systems and Environment 4:1537–1554

Hengl and Evans, 2009 (Mathematical and Digital Models of the Land Surface, in: Hengl, T., Reuter, H.I. (Eds.), Geomorphometry: Concepts, Software, Applications

Aguilar FJ, Agüera F, Aguilar M, Carvajal F (2005) Effects of terrain morphology, sampling density, and interpolation methods on grid DEM accuracy. Photogramm Eng Remote Sens 71:805–816

Anderson ES, Thompson JA, Crouse DA, Austin RE (2005) Horizontal resolution and data density effects on remotely sensed LIDAR based DEM. Geoderma 132:406–415

Kienzle S (2004) The effect of DEM raster resolution on first order, second order and compound terrain derivatives. Trans GIS 8:83–111

Thompson JA, Bell JC, Butler CA (2001) Digital elevation model resolution: effects on terrain attribute calculation and quantitative soil landscape modeling. Geoderma 100:67–89

>> Line 118 : statistic indicator

>> Line 128 to 130 : This sentence should be rephrased, because is too long and contains lot of information “The larger the entropy is, the larger the information capacity value is, which means the better the expression degree of the entropy is and the richer the surface information content is.”

>> Line 146 : Add a North arrow and a legend to the map in Figure 1. The inset map should show the location of the study area in accordance to whole China.

>> Line 149 to 151 : what do you mean by field digital mapping and remote sensing mapping methods. Did you add more information coming from those methods to the topographic maps? If yes please specify. If no, there is no need to mention that.

>> Line 167 : Did you mean Figure 3?

>> Line 182 : expressed by four kinds of roughness extraction algorithms.

>> Line 237 : the high frequency (hilly area) information

>> Line 294 to 350 : References should be reorganized with an alphabetical order. All references should have to be revised and corrected because there are some errors in DOI, dates, etc. There is two examples :

>> Line 294 to 295 : the DOI is wrong. This is the right DOI https://doi.org/10.1016/j.earscirev.2014.05.016

>> Line 299 : Date of publication is 2005 and it’s not 2010. It should be corrected.

Author Response

Revision Notes

Dear reviewers and editors,

Thank you very much for your supervision of the reviewing process of our manuscript with the reference number of ijgi-409285. We also highly appreciate your and reviewer’s carefulness, conscientious, and the broad knowledge on the relevant research fields, since you and reviewer has given a number of beneficial suggestions.

According to reviewers’ comments, we have finished manuscript revision work. We hope that these revisions are satisfactory and that the revised version will be acceptable for publication in International Journal of Geo-Information..

Thank you very much for your work concerning my paper.

Wish you all the best!

Sincerely yours,

Jiang Wu

2019-3-10

Reviewer #1:

According to your and reviewer’s criticism and instruction, we have made the following revisions:

Response to Reviewer 1 Comments

Thank you very much for your constructive comments and suggestions, which will greatly improve the quality of my research paper.

1. Line 16 : Fuyang, a 16 district of Hangzhou city with various landform types, is selected as the research area.

Response: Thank you for your suggestion. It has already been modified. After a detailed introduction, the abbreviations were used in the article.

(see Line 16)

2. Line 17 to 19: Try to rephrase this sentence “and slope, root mean squared height, vector deviation, and two-dimension continuous wavelet transform are the parameters measured by these four typical roughness algorithms”

Response: Thank you for your suggestion. It has already been modified as “Slope, root mean squared height, vector deviation, and two-dimension continuous wavelet transform were selected as four typical roughness algorithms”.

(see Line 17)

3. Line 19 and 20: The resolutions used are 5, 10, 19 25, and 50 m DEM for plain, hilly, and mountains areas.

Response: Thank you for your suggestion. It has already been modified.

(see Line 19)

4. Line 22 : The expression ability of the two algorithms => specify the two algorithms in the text

Response: Thank you for your suggestion. It has already been modified.

(see Line 22)

5. Line 47 : McKean and Roering, and Glenn and Booth carried

Response: Thank you for your suggestion. It has already been modified.

(see Line 47)

6. Line 51 : 10 kinds of algorithms

Response: Thank you for your suggestion. It has already been modified.

(see Line 50)

5. Line 59 to 74: the authors give a good understanding of the impact of spatial resolution on DEM quality. However, I advise to add the suggested references in the version 1 of this review, because these references contains recent, old and some fundamental research papers, which are :

Hengl and Evans, 2009 (Mathematical and Digital Models of the Land Surface, in: Hengl, T., Reuter, H.I. (Eds.), Geomorphometry: Concepts, Software, Applications

Aguilar FJ, Agüera F, Aguilar M, Carvajal F (2005) Effects of terrain morphology, sampling density, and interpolation methods on grid DEM accuracy. Photogramm Eng Remote Sens 71:805–816

Anderson ES, Thompson JA, Crouse DA, Austin RE (2005) Horizontal resolution and data density effects on remotely sensed LIDAR based DEM. Geoderma 132:406–415

Kienzle S (2004) The effect of DEM raster resolution on first order, second order and compound terrain derivatives. Trans GIS 8:83–111

Thompson JA, Bell JC, Butler CA (2001) Digital elevation model resolution: effects on terrain attribute calculation and quantitative soil landscape modeling. Geoderma 100:67–89

Response: Thank you for your suggestion, I have inserted these documents into the introduction.

(see Line 61)

6. Line 118 : statistic indicator

Response: Thank you for your suggestion. It has already been modified.

(see Line 118)

7. Line 128 to 130 : This sentence should be rephrased, because is too long and contains lot of information “The larger the entropy is, the larger the information capacity value is, which means the better the expression degree of the entropy is and the richer the surface information content is.”

Response: Thank you for your suggestion. It has already been modified to “when the entropy is larger, the information capacity value is bigger. This means the expression degree of the entropy will be better and the surface information content will be richer”.

(see Line 128)

8. Line 146 : Add a North arrow and a legend to the map in Figure 1. The inset map should show the location of the study area in accordance to whole China.

Response: Thank you for your suggestion. It has already been modified.

(see Line 146)

9. Line 149 to 151 : what do you mean by field digital mapping and remote sensing mapping methods. Did you add more information coming from those methods to the topographic maps? If yes please specify. If no, there is no need to mention that.

Response: Thank you for your suggestion. The description here is to explain the production method of the topographic map, which has been deleted according to your opinion.

(see Line 150)

10. Line 167 : Did you mean Figure 3?

Response: Yes. It has already been modified.

(see Line 169)

11. Line 182 : expressed by four kinds of roughness extraction algorithms.

Response: Thank you for your suggestion. It has already been modified.

(see Line 185)

12. Line 237 : the high frequency (hilly area) information

Response: Thank you for your suggestion. It has already been modified.

(see Line 240)

13. Line 294 to 350 : References should be reorganized with an alphabetical order. All references should have to be revised and corrected because there are some errors in DOI, dates, etc. There is two examples :

>> Line 294 to 295 : the DOI is wrong. This is the right DOI https://doi.org/10.1016/j.earscirev.2014.05.016

>> Line 299 : Date of publication is 2005 and it’s not 2010. It should be corrected.

Response: Thank you for your suggestion. It has already been modified.

(see Line 298)

Author Response File: Author Response.docx

Reviewer 2 Report

I am satisfied with your response to my remarks.

Author Response

Revision Notes

Dear reviewers and editors,

According to reviewers’ comments, we have finished manuscript revision work.

We hope that these revisions are satisfactory and that the revised version will be acceptable for publication in International Journal of Geo-Information.

Thank you very much for your work concerning my paper.

Wish you all the best!

Sincerely yours,

Jiang Wu

2019-3-10

Reviewer #2:

According to your and reviewer’s criticism and instruction, we have made the following revisions:

Response to Reviewer 2 Comments

Thank you for your help with my manuscript, I will work harder.

Author Response File: Author Response.docx

Reviewer 3 Report

Reviewers Feedback

It is good to see this manuscript with improvement. However, before final publication it would be nice if the authors can consider some minor things.

Specific comments

1. Please consider writing in a consistent way. In line 13: DEM(Digital elevation model) whereas in line 89: root mean squared height (RMSH). I think both of them are correct but you must use any of them consistently.

2. Line 78: Please re-write this line to make it clear.

3. The second paragraph of the introduction is too long. It would be nicer if the authros can break it down to two.

4. Line 167: “For study area C,……shown in Figure 2”. It is not directed to the right figure. Is it?

5. The caption of the Figure 3 needs to be improved by re-writing.

6. The discussion needs to reinforce with more references.

Author Response

Revision Notes

Dear reviewers and editors,

According to reviewers’ comments, we have finished manuscript revision work.

We hope that these revisions are satisfactory and that the revised version will be acceptable for publication in International Journal of Geo-Information.

Thank you very much for your work concerning my paper.

Wish you all the best!

Sincerely yours,

Jiang Wu

2019-3-10

Reviewer #3:

According to your and reviewer’s criticism and instruction, we have made the following revisions:

Response to Reviewer 3 Comments

Thank you for reviewing my work during your busy schedule, thank you for your constructive comments and suggestions, which will greatly improve the quality of my research paper. Finally, i express my sincere gratitude for your scientific and rigorous attitude.

Response: Thank you for your suggestion. It has already been modified. After a detailed introduction, the abbreviations were used in the article

2. Line 78: Please re-write this line to make it clear.

Response: Thank you for your suggestion. It has already been modified to “This paper selected Zhejiang Fuyang District with various landforms as the research area”.

(see Line 78)

3. The second paragraph of the introduction is too long. It would be nicer if the authros can break it down to two.

Response: Thank you for your suggestion. It has already been modified.

(see Line 59)

4. Line 167: “For study area C,……shown in Figure 2”. It is not directed to the right figure. Is it?

Response: Thank you for your suggestion. It has already been modified.

(see Line 169)

5. The caption of the Figure 3 needs to be improved by re-writing.

Response: Thank you for your suggestion. It has already been modified.

(see Line 140)

6. The discussion needs to reinforce with more references.

Response: Thank you for your suggestion. It has already been modified. Since all of my discussion is based on previous roughness studies, the literature was inserted at the corresponding location.

(see Line 230)

Author Response File: Author Response.docx

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The proposed manuscript authors tried to evaluate terrain expression and roughness algorithm based on different DEM resolution. The content may fit with the aim and scope with this journal but need a drastic improvement.

General comments

1. The current state of this manuscript is no more than a class assignment.

2. The writing expressions is not standard for this stage. There are syntaxes and spelling errors everywhere.

3. Authors failed to justify the research need and also undervalued decade of research on DEM. Hence, I suggest to put it through a professional language editing service. Also, cite and discuss more related research in this field.

4. The whole manuscript needs to be re-organised properly.

5. Tables and figures need to be improved further by adding more clarity and appropriate caption.

6. The methodology is not clear. It must be improved by providing flow-chart and proper explanation.

Reviewer 2 Report

The article is interesting but it might be useful to add some details regarding the technical quality of the DEM used, e.g. the accuracy of the models, the interpolation algorithms used for DEM creation (I assume that only one basic source was used from all four DEMs), whether DEMs are hydrologically correct digital elevation models, or just simply interpolated raster sets, what procedure has been chosen for creating a DEM with a larger pixel (e.g. type of resampling, etc.). In fact the technical quality of DEM and methods of its creation can influence its properties, mainly modelled details of original terrain relief.

Very interesting could be a comparison with TIN DEM, but I know that such complication would exceed the required range of the article.

Next are some small mistakes:

Correct please terminology, e.g. effect size and effect-size.

Line 141 - gap between resolution and SLOPE is missing

Line 160 - delete gap between RM and SH

There are different DEM pixel resolution in Figure 3 (5, 10, 15, 20 m) than in the other text. It is not clear whether presented charts (c) and (d) answer to resolution of 25 and 50 m or 15 and 20 m

Line 175 - what does small terrain mean?

Reviewer 3 Report

This paper addresses an assessment of roughness algorithms in terms of different spatial resolution of DEM. The content fits with the topics covered by this journal. It’s interesting but it might be useful to add some details regarding the technical quality of the DEM used, e.g. the accuracy of the models, the interpolation algorithms used for DEM creation, whether DEMs are hydrologically correct digital elevation models, or just simply interpolated raster sets, what procedure has been chosen for creating a DEM with a larger pixel (e.g. type of resampling, etc.). The paper can be accepted, however, the contents should be further deepened for the publication.

Major comments

>> The methodology should be improved and a flowchart should be added.

>> Line 148 to 155: you mentioned that all tested algorithms give the same range of roughness and the structure unchanged. The reviewer don’t agree with that since the results of VD and 2D CWT give opposite results to SLOPE and RMSH specifically for coarse resolution. This issue should be revised and carefully analyzed.

>> The discussion needs to be further developed. It should describe the relationship of each chosen indicator (Surface features, ES and Entropy) and the roughness algorithms and also how roughness varies in each geomorphological unit in terms of spatial resolution.

Minor comments

>> Line 56 to 57: there is a difference between grid resolution and grid size (also called cell size). by increasing the grid resolution, the cell size will become smaller and the other way around. Try to get a look on Hengl and Evans, 2009 (Mathematical and Digital Models of the Land Surface, in: Hengl, T., Reuter, H.I. (Eds.), Geomorphometry: Concepts, Software, Applications.

>> Line 57 to 60: try to get look on these references in order to give a deep understanding about the impact of DEM spatial resolution on its quality.

Aguilar FJ, Agüera F, Aguilar M, Carvajal F (2005) Effects of terrain morphology, sampling density, and interpolation methods on grid DEM accuracy. Photogramm Eng Remote Sens 71:805–816

Anderson ES, Thompson JA, Crouse DA, Austin RE (2005) Horizontal resolution and data density effects on remotely sensed LIDAR based DEM. Geoderma 132:406–415

Kienzle S (2004) The effect of DEM raster resolution on first order, second order and compound terrain derivatives. Trans GIS 8:83–111

Thompson JA, Bell JC, Butler CA (2001) Digital elevation model resolution: effects on terrain attribute calculation and quantitative soil landscape modeling. Geoderma 100:67–89

>> Line 81: RMSH is to quantify that surface …… => RMSH is used to quantify the surface

>> Line 84: VD refers to express the roughness………. => VD express

>> Line 123: 119°25’E instead of E119°25′ (same remark for the other values)

>> Line 126: do you mean “a river valley” by the term “basin”? If not try to be more specific

>> Line 138: clipped instead of clip

>> Line 134 to 139: Is the DEM is hydrologically corrected? If not, you should do it. This step is very important to get a valuable roughness values.

The choice of TIN interpolation method should be justified.

The quantitative accuracy of the 1:10,000 map should be specified.

>> Line 145: Justify the choice of area C for surface features analysis

>> Line 160: “SLOPE and RMSH algorithms have” instead of “SLOPE and RM SH these two algorithms have

>> Line 163: “reduces” instead “redeces”