Study on Morphometrical Urban Aerodynamic Roughness Multi-Scale Exploration Using LiDAR Remote Sensing

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript (remotesensing-3007972) tries to explore the linkage between aerodynamic roughness length analysis and building placement management in an urban setting. The authors have conducted visual and statistical comparisons of the results of aerodynamic roughness length and displacement height calculated using different estimation methods for different grid sizes and resolutions. Although the study is a complete one, its novelty and contribution to remote sensing community needs to be highlighted throughout the manuscript. Another serious concern is that some related latest research has been ignored. More detailed suggestions and comments are shown in the following:

- . In the Abstract, many sentences are too vague that readers cannot grasp the key scientific questions. For example, "our understanding of the specificity of LiDAR RS for identifying building placement and the related data interpretation is insufficient", why? And what are the gaps exactly?

- . I am also missing the key results and conclusions in the Abstract.

- . This manuscript did not elaborate in depth on the principles of LiDAR RS for accurate detection of urban building, the complexity of data processing, and the specific background of its application in urban planning or environmental science.

- . Please explain clearly how to extract aerodynamic roughness related information from LiDAR 3DPC dataset.

- . I suggest to present some sample records of the Airborne LiDAR 3DPC and Digital Photograph datasets in a new figure.

- . In Section 2. Materials and Methods, I am missing the overall technical framework of this research.

- . What is the computational complexity? Especially when dealing with these large-scale data sets. Therefore, in practical applications, computing resource and time constraints need to be considered.

- . The whole study mainly focuses on urban areas. How applicable is it to other types of areas (such as rural and low-density areas)?

- . This manuscript did not provide comparative validation with other methods (such as ground surveys, other remote sensing techniques), which limits the application of the results. In addition, there is a lack of comparative research with other cities or regions.

- . I suggest the future research should further explore how these fine-grained 3D building placement results can be used in actual urban management and planning efforts, such as floods. Please refer to below for examples.

Assessing the scale effect of urban vertical patterns on urban waterlogging: an empirical study in Shenzhen, 2024, 107486.

Evaluating the effect of building patterns on urban flooding based on a boosted regression tree: A case study of Beijing, China

- . In the Discussion Section, the manuscript should explore the implications and limitations of the findings in more depth and discuss possible directions for improvement. The current Discussion and Conclusion did not fully explain the deeper implications of the findings.

- . I also wonder whether the software will be made available to the public scientific communities.

Comments on the Quality of English Language

Moderate editing of English language required.

Author Response

This manuscript (remotesensing-3007972) tries to explore the linkage between aerodynamic roughness length analysis and building placement management in an urban setting. The authors have conducted visual and statistical comparisons of the results of aerodynamic roughness length and displacement height calculated using different estimation methods for different grid sizes and resolutions. Although the study is a complete one, its novelty and contribution to remote sensing community needs to be highlighted throughout the manuscript. Another serious concern is that some related latest research has been ignored. More detailed suggestions and comments are shown in the following:
- . In the Abstract, many sentences are too vague that readers cannot grasp the key scientific questions. For example, "our understanding of the specificity of LiDAR RS for identifying building placement and the related data interpretation is insufficient", why? And what are the gaps exactly?
- . I am also missing the key results and conclusions in the Abstract.
→ Reflecting on your review, we have rewritten the text. Please see the Abstract and Discussions sections.
- . This manuscript did not elaborate in depth on the principles of LiDAR RS for accurate detection of urban building, the complexity of data processing, and the specific background of its application in urban planning or environmental science.
→ Reflecting on your review, we have rewritten the text. Please see Abstract, Introduction and Discussions.
- . Please explain clearly how to extract aerodynamic roughness related information from LiDAR 3DPC dataset.
→ Reflecting your review, we have added more Figure with equations and rewritten the text. Please see Abstract, Introduction and Discussions.
- . I suggest to present some sample records of the Airborne LiDAR 3DPC and Digital Photograph datasets in a new figure.
→ Reflecting your review, we have rewritten the text and redraw the figure. Please see Figure 3and 3.1. Single Building Scale 3DPC and Aerodynamic Roughness map exploration
- . In Section 2. Materials and Methods, I am missing the overall technical framework of this research.
- . What is the computational complexity? Especially when dealing with these large-scale data sets. Therefore, in practical applications, computing resource and time constraints need to be considered.
→ Reflecting on your review we rewrote methods and added technical workflow in Figure 2.
- . The whole study mainly focuses on urban areas. How applicable is it to other types of areas (such as rural and low-density areas)?
→ As shown in Figure 5 and Figure 8, this approach can apply to various kinds of settlement areas.
- . This manuscript did not provide comparative validation with other methods (such as ground surveys, other remote sensing techniques), which limits the application of the results. In addition, there is a lack of comparative research with other cities or regions.
→ It is a limitation of this study, but we provided a research direction for that. Reflecting on your review, we rewrote the discussions. Please see 4.1. Morphometric Method: Urban Building Placement Qunatificatoin and 4.2. Observational Method: Verification of Urban Climate Influence.
- . I suggest the future research should further explore how these fine-grained 3D building placement results can be used in actual urban management and planning efforts, such as floods. Please refer to below for examples.
Assessing the scale effect of urban vertical patterns on urban waterlogging: an empirical study in Shenzhen, 2024, 107486.
Evaluating the effect of building patterns on urban flooding based on a boosted regression tree: A case study of Beijing, China
→ Reflecting your review, we cited those references.
- . In the Discussion Section, the manuscript should explore the implications and limitations of the findings in more depth and discuss possible directions for improvement. The current Discussion and Conclusion did not fully explain the deeper implications of the findings.
→ Reflecting on your review, we rewrote the discussions.
- . I also wonder whether the software will be made available to the public scientific communities.
→ We agreed public use of the proposed method and developed tool though it is not a complete version. We are ready to listen and follow reviewer's guide for the open use.
Comments on the Quality of English Language Moderate editing of English language required.
→ Reflecting your review, we have rewritten the text.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

 

      1.        Line 197, What is NGII?

      2.         Line 238-239, Any specific reason for considering only the square grids (2x2, 12x12, 60x60, and so on) in the submitted manuscript.

 

      3.         More details about the methodology on Section 2.2.2 is required as the details shared is minimal and difficult to understand the method as a whole.

 

      4.         Fig. 5, the naming of the figures (a, b, c) must be under each figure at the center.

 

     5. Interpretation of the values in Table 4 is required.

 

      6.           Line 485, the author mention that this study “emphasizes the establishment of a LiDAR 3DPC database for the 485 morphometric analysis of urban buildings” which is contradictory to the title of the submitted manuscript. I suggest modifying the title to suit the methodology of the paper.

      7.           Citations necessary for the below:

a.      Line 93-94, citation for the LiDAR three-dimensional point cloud (3DPC) dataset constructed by the National Geographic Information Institute (NGII). If it is a self-developed dataset, it should be made available publicly to evaluate the proposed method.

b.      All the datasets listed in Table 1 is necessary.

c.       Line 124, for the MCI technique is necessary.

d.      Line 186, An’s SVF analysis

e.      Line 199, South Korea building regulations

f.       Line 213, NGII Digital Map (Building)

g.      Line 219, Qt and Microsoft Foundation Class libraries

h.      Line 242-243, for ASCII

i.        Line 483, for UHI mitigation

 

 

Comments on the Quality of English Language

Certain explanations to be elaborated to increase the readability of the paper.

I suggest overall proofreading of the paper by a native English speaker.

Author Response

Line 197, What is NGII?
→ NGII is the abbreviation of National Geographic Information Institute.
2. Line 238-239, Any specific reason for considering only the square grids (2x2, 12x12, 60x60, and so on) in the submitted manuscript.
→ Reflecting your review, we added the reason why multi-scale exploration is need on the Introduction. Please see lines 43-56.
3. More details about the methodology on Section 2.2.2 is required as the details shared is minimal and difficult to understand the method as a whole.
→ Reflecting your review, we have added more equations and rewritten the text. Please see Methods (Lines 118-176, Figure 2).
4. Fig. 5, the naming of the figures (a, b, c) must be under each figure at the center.
→ Reflecting your review, we have added the naming on the figure.
5. Interpretation of the values in Table 4 is required.
→ Reflecting your review, we have added more interpretation.
6. Line 485, the author mention that this study “emphasizes the establishment of a LiDAR 3DPC database for the 485 morphometric analysis of urban buildings” which is contradictory to the title of the submitted manuscript. I suggest modifying the title to suit the methodology of the paper.
→ Reflecting your review, we modified the title as “A study on Morphometrical Urban Aerodynamic Roughness Multi-Scale Exploration Using LiDAR Remote Sensing”.
7. Citations necessary for the below:
a. Line 93-94, citation for the LiDAR three-dimensional point cloud (3DPC) dataset constructed by the National Geographic Information Institute (NGII). If it is a self-developed dataset, it should be made available publicly to evaluate the proposed method.
→ We acquired the classified LiDAR 3DPC data from NGII (only offline access is available for security reasons). We agreed public use of the proposed method and developed tool though it is not a complete version. We are ready to listen and follow reviewer's guide for the open use.
b. All the datasets listed in Table 1 is necessary.
→ Citation added. However, many data acquisition from the site is unavailable (only offline access is available for security reasons).
c. Line 124, for the MCI technique is necessary.
→ The line was deleted to avoid confusing the reader.
d. Line 186, An’s SVF analysis
→ Citation added. [25]
e. Line 199, South Korea building regulations
→ Rewrote. Citation added. [59] (law.go.kr)
f. Line 213, NGII Digital Map (Building)
→ Citation added. [58] NGII. The National Atlas of KoreaII 2020. Available online: http://nationalatlas.ngii.go.kr/pages/page_2409.php
g. Line 219, Qt and Microsoft Foundation Class libraries
→ Citation added. [53] Dalheimer, M. Programming with QT: Writing portable GUI applications on Unix and Win32. O'Reilly Media, Inc.. 2002.
h. Line 242-243, for ASCII
→ Citation added. [54]. Farkas, G. Possibilities of using raster data in client‐side web maps. Transactions in GIS, 2020, 24(1), 72-84.
i. Line 483, for UHI mitigation
→ The line has been deleted.

Reviewer 3 Report

Comments and Suggestions for Authors

On the face of it, this paper discusses an interesting application of LiDAR for aerodynamic roughness analysis at a city scale. While the content is engaging, I suggest that the authors reorganize the structure and focus on the main contribution and novelty of the paper to better highlight its strengths and selling points. Currently, it seems quite vague across the paper, even in the abstract. The paper appears to mix several elements without clearly defining the primary contribution. Specifically, it reads like a comparison of two existing LiDAR processing approaches over a relatively small region with few new findings. Below are some additional concerns: 1) How generalizable and applicable are the approach and findings? 2) Line 170: It reads like that the accuracy of the method was compromised to better integrate it into a GUI? How does the selected method perform compared to the state-of-the-art (SOTA) methods? 3) The GUI does not seem to provide significant additional scientific value for this paper. Moreover, the screenshots of the GUI currently displayed are of relatively poor image quality. Is there a specific reason for presenting the parameters and options in screenshots rather than in an easy-to-read table?

Author Response

On the face of it, this paper discusses an interesting application of LiDAR for aerodynamic roughness analysis at a city scale. While the content is engaging, I suggest that the authors reorganize the structure and focus on the main contribution and novelty of the paper to better highlight its strengths and selling points. Currently, it seems quite vague across the paper, even in the abstract. The paper appears to mix several elements without clearly defining the primary contribution.
Specifically, it reads like a comparison of two existing LiDAR processing approaches over a relatively small region with few new findings. Below are some additional concerns:
1) How generalizable and applicable are the approach and findings?
→ The current level is a bit far from generalizable. Reflecting on your review, we have rewritten the text. Please see methodology and discissions.
2) Line 170: It reads like that the accuracy of the method was compromised to better integrate it into a GUI? How does the selected method perform compared to the state-of-the-art (SOTA) methods?
→ Reflecting your review, we introduced SOTA in discussions. However, it is difficult to determine state-of-the-art (SOTA) methods, however lately introduced methods were added.
3) The GUI does not seem to provide significant additional scientific value for this paper. Moreover, the screenshots of the GUI currently displayed are of relatively poor image quality. Is there a specific reason for presenting the parameters and options in screenshots rather than in an easy-to-read table?
→ Main purpose is supporting relevant research. Contemporary PC computing power is enough. Please see 4.1. Morphometric Method: Urban Building Placement Quantification. GUI interface parameters are currently being applied in major research papers. These parameters are not based on local observations but may be modified by future observations of the region. Please see Table2.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for incorporating my previous comments and suggestions. This manuscript can be accepted in present form.

Author Response

Thank you for incorporating my previous comments and suggestions. This manuscript can be accepted in present form.

--> Thank you for your kind words and positive feedback. We are pleased to hear that the revisions meet your approval. We appreciate your thorough review and are grateful for your suggestions. Thank you once again for your valuable input.

Reviewer 2 Report

Comments and Suggestions for Authors

Thanks to the authors for addressing the comments/suggestions in the Review-1. However, I would like to further suggest:

1. The authors report that the citations were added for all the datasets listed in Table 1 is necessary. Whereas I couldn't find any citations of these data listed in Table 1. I recommend authors to cite these datasets. In case of Offline datasets, the data employed in the submitted manuscript to made available via Data Consent Form along with this submission for the readers to evaluate the proposed methodology in this manuscript.

2. Same as above point 1 for citing the LiDAR three-dimensional point cloud (3DPC) dataset constructed by the NGII. 

 

Comments on the Quality of English Language

The quality of the English used is decent although it could be better. Proofreading by a native speaker is recommended.

Author Response

1. The authors report that the citations were added for all the datasets listed in Table 1 is necessary. Whereas I couldn't find any citations of these data listed in Table 1. 
I recommend authors to cite these datasets. In case of Offline datasets, the data employed in the submitted manuscript to made available via Data Consent Form along with this submission for the readers to evaluate the proposed methodology in this manuscript.
--> Reflecting on your review, we have added a citation to the best of our ability. However, citing LiDAR data remains limited as it is preliminary data for the digital elevation model (DEM). Therefore, we included a note regarding this limitation. Please refer to Table 1 for further details.

2. Same as above point 1 for citing the LiDAR three-dimensional point cloud (3DPC) dataset constructed by the NGII. 
--> We also contacted the Smart Spatial Information Division, NGII, who is responsible for the airborne laser survey, to request 100m by 100m LiDAR 3DPCs for public validation. If NGII approves, we will follow your recommendation and promptly add this information to the manuscript.

Comments on the Quality of English Language
The quality of the English used is decent although it could be better. Proofreading by a native speaker is recommended.
--> We made a small change to the manuscript and consulted an expert with experience in SCI journals to enhance its quality for better reader understanding. The improvements will be incorporated during proofreading.