Evaluation of Underground Space Resources in Ancient Cities from the Perspective of Organic Renewal: A Case Study of Shaoxing Ancient City

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The study carried out by the authors is currently relevant, especially considering the importance of preserving historical environments in urban areas. Developing an indicator system to assess underground development and its potential conflicts with historically significant sites is very useful in similar situations.

The following recommendations are suggested for the authors to enhance readability and emphasize the research process.

1. Abstract and Introduction
   1. Because the theme and research question of the article develop the “organic renewal” concept, it is necessary to explore the reasons why the authors based their analysis on this particular approach. As mentioned in 15-17, there are three types of urban renewal, so it is essential to briefly explain some characteristics of each renewal type and the reasons why “organic renewal” is the most suitable as the methodological background.
   2. (29-36) In the abstract, it is highly recommended to include more specific findings of the study. The authors have more relevant information that is important to include in the abstract to help the reader understand the significance of the methodology used.
   3. (55-58) The authors briefly mentioned what “organic renewal” is and its main features. However, it is crucial to explore this concept more deeply. For Western readers, it will be interesting to understand its background, especially considering that it was proposed for the Chinese context (i.e., by Wu Liangyong since 1979).
2. Literature review
   1. (123-127) It is highly recommended for the authors to deepen their literature review on past applications of USDP or clarify its applicability in the Chinese context.
   2. A more detailed literature review about “organic renewal” would be beneficial to help readers understand its main characteristics and the reason why the authors have used this for this particular analysis.
3. Methodology
   1. (208) Please clearly explain the limitations mentioned regarding considering engineering technology.
   2. (215, 228-229, 233-234) A more thorough literature review will help clarify the considerations in the evaluation model.
   3. (241, Figure 2.) This figure is essential for understanding the framework of indicators concerning the potential of USD in historical environments. However, a workflow of the research process would be helpful to illustrate how the authors conducted their analysis and process using Geographic Information Systems.
   4. Compared to the Results and Analysis section, the Methodology could be simplified to include only the most relevant details. The tables throughout the article, especially in the Methodology, are hard to read because the rows are not easy to distinguish.
   5. Tables of indicators need to be linked with equations to understand their relationship with the analysis and subsequent results. 
4. Results and Analysis
   1. (530) Figure 8 is unclear. The elements listed in the legend are not explained in the main text.
5. Conclusions
   1. As noted in the recommendations for the introduction and literature review, the conclusions highlight the importance of “organic renewal.” It is crucial to consider this aspect in emphasizing the conclusions drawn from the authors' analysis.

Comments on the Quality of English Language

The English used in the manuscript is generally understandable. A review by a native speaker or professional editing service is recommended.

Author Response

1. Summary

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections shown in track changes in the re-submitted files. Our responses are in black, quoted text from the old version of the manuscript is in gray, and quoted text from the revised version is in red.

 

2. Questions for General Evaluation	Reviewer’s Evaluation	Response and Revisions
Does the introduction provide sufficient background and include all relevant references?	Must be improved
Is the research design appropriate?	Must be improved
Are the methods adequately described?	Must be improved
Are the results clearly presented?	Can be improved
Are the conclusions supported by the results?	Can be improved
Are all figures and tables clear and well-presented?	Must be improved

3. Point-by-point response to Comments and Suggestions for Authors

Comments 1:

①Because the theme and research question of the article develop the “organic renewal” concept, it is necessary to explore the reasons why the authors based their analysis on this particular approach. As mentioned in 15-17, there are three types of urban renewal, so it is essential to briefly explain some characteristics of each renewal type and the reasons why “organic renewal” is the most suitable as the methodological background.

②(55-58) The authors briefly mentioned what “organic renewal” is and its main features. However, it is crucial to explore this concept more deeply. For Western readers, it will be interesting to understand its background, especially considering that it was proposed for the Chinese context (i.e., by Wu Liangyong since 1979).

Response 1:

Thank you very much for your valuable suggestion. We choose "organic renewal" as the methodological background for the following reasons:

Ancient cities are rich in historical and cultural heritage, which constitutes an essential part of urban culture and history. However, currently, the public infrastructure in ancient cities can no longer meet residents' daily living needs, so urban renewal is urgently required.

Traditional urban renewal approaches such as "demolition and reconstruction" or "comprehensive improvement" tend to damage the historical context of ancient cities. Moreover, they have limited effects on addressing the space shortage issue in ancient cities while preserving historical heritage.

In contrast, "organic renewal" is based on the principle of respecting historical heritage and proposes a "gradual, patch - like" renovation method. This approach enables the renewal of ancient cities while maximizing the protection of historical and cultural heritage, making it more suitable for the renewal of ancient cities with abundant historical and cultural heritage (such as Shaoxing Ancient City). Therefore, this paper takes organic renewal as the research background.

 

Thank you for pointing this out. We agree with this comment. We have supplemented the relevant content in the introduction section (lines 46–71).

①Regarding the explanation of urban renewal types:

We have clearly defined the three types of urban renewal models, and the relevant content has been supplemented in the revised manuscript. The specific revisions are as follows:

There are three main types of urban renewal: "demolition and reconstruction", "comprehensive improvement", and "organic renewal". "Demolition and reconstruction" is based on the demolition of large-scale old buildings and the construction of new ones. "Comprehensive improvement" focuses on upgrading existing structures and public spaces without full-scale demolition, including repairs to aging components, the modernization of facilities, and environmental enhancements to improve livability[3]. "Organic renewal" is a renovation approach based on the principle of respecting historical heritage, featuring a "gradual, patch-like" method[4](new version: lines 46–54).

 

②Regarding the in-depth exploration of the "organic renewal" concept and its background:

We have supplemented the academic background of "organic renewal". These supplements aim to help Western readers understand the uniqueness of its context. The specific revisions are as follows:

It was proposed by Prof. Wu in the 1970s to resolve the contradiction between urban construction and historical preservation in China (new version: lines 63–65). We also clarified that this "organic renewal" concept can effectively balance the protection of ancient city culture and the expansion of spatial functions, providing a theoretical foundation for the construction of the evaluation system for the underground space of ancient cities. (new version: lines 69–71).

Comments 2: (29-36) In the abstract, it is highly recommended to include more specific findings of the study. The authors have more relevant information that is important to include in the abstract to help the reader understand the significance of the methodology used.

Response 2:

Thank you for pointing this out. We agree with this comment. We have supplemented more specific findings of the study in the abstract section (lines 30–33).These specific findings help illustrate the practical significance of the applied methodology in identifying underground space development potentials within the ancient city context. The specific revisions are as follows:

(old version: lines 29-31)

High-potential areas were primarily concentrated in or near train transit stations, public service facilities, evacuated land, and cultural and tourism facilities around historic districts.

(new version：lines 30-33)

High-potential areas accounted for 16.38% of the total evaluation area and were primarily concentrated in or near key locations: train transit stations (Shaoxing Railway Station), public service facilities, evacuated land, and cultural and tourism facilities around historic districts (Shusheng Guli Historical and Cultural Street).

 

Comments 3:

①(123-127) It is highly recommended for the authors to deepen their literature review on past applications of USDP or clarify its applicability in the Chinese context.

②A more detailed literature review about “organic renewal” would be beneficial to help readers understand its main characteristics and the reason why the authors have used this for this particular analysis.

Response 3:

Thank you for pointing this out. We agree with this comment. We have enhanced the literature review section (lines 132–140) in two key aspects. The specific revisions are as follows:

①For the literature review on past applications of USDP and clarification of its applicability in the Chinese context: We have deepened this part by incorporating relevant studies (Li Kuo et al.), which reveal that while USDP has been applied in some urban projects in China, its integration with the "organic renewal" principle in ancient city conservation scenarios remains under-explored. (new version: lines 134–136)

②Regarding the literature review on "organic renewal": We have supplemented application cases of "organic renewal" in ancient cities, such as Hong’s research on the development models and strategies of underground space in ancient cities, which emphasizes that the concept of organic renewal has become the core framework for the protection of ancient cities in China, yet its integration with underground space evaluation remains relatively weak and calls for further exploration. (new version: lines 136–140)

 

Comments 4: (208) Please clearly explain the limitations mentioned regarding considering engineering technology.

Response 4:

Thank you for your valuable comment. We have revised the method section (Section 4.1) of this paper to clearly explain the limitations related to engineering technology and ancient city protection. Specifically, we supplemented the explanation that: due to the constraints of ancient city protection and the limited current geological survey accuracy and construction level, when developing underground space deeper than -30 meters, it is not only difficult to avoid damaging the historical architectural style and spatial pattern of the ancient city, but also hard to ensure construction safety and cost-effectiveness (new version: lines 237-241). Therefore, this study focuses on the depth range from 0 to -30m in SAC. We believe that this revision makes the limitations of the study and the basis for selecting the depth range more explicit.

 

Comments 5: (215, 228-229, 233-234) A more thorough literature review will help clarify the considerations in the evaluation model.

Response 5:

Thank you for pointing this out. We agree with this comment. Specifically, we have supplemented relevant literature on evaluation indicators such as ecological environment protection and historical and cultural protection in the article (new version: lines 254-258). Meanwhile, we have also added literature for the dimensional indicators of "Spatial quality improvement, Transportation efficiency enhancement, Spatial value increment, and Functional deficiency remedying" (new version: lines 271-275). These supplements are intended to more clearly explain the theoretical basis and considerations for each component of the evaluation model in the method section (Section 4.2: Evaluation Model).

 

Comments 6: (241, Figure 2.) This figure is essential for understanding the framework of indicators concerning the potential of USD in historical environments. However, a workflow of the research process would be helpful to illustrate how the authors conducted their analysis and process using Geographic Information Systems.

Response 6:

Thank you for your valuable comment. We agree with this suggestion, but would like to explain the following: Figure 2 focuses on the "USDP evaluation indicator system framework constructed based on development suitability and development demand," and its core function is to clearly present the overall logic and hierarchical relationship of the indicator system. While the application of ArcGIS runs through the entire evaluation process. Specifically, this process ranges from preliminary analysis and spatial data processing for indicators such as "transportation facility connectivity," "floating population concentration," and "commercial land value" to the evaluation and calculation of single factors, development demand, and development suitability, and finally to the visualization of all results. All of these steps are completed using this software.

 If these detailed GIS application processes were additionally added to Figure 2, it would easily lead to information overload on the figure and overshadow the core indicator framework, which would instead hinder the communication of key information. Therefore, we are temporarily unable to supplement the specific ArcGIS application links in this figure. However, through the detailed textual elaboration in this response, we have fully and clearly demonstrated the penetrating supporting role of GIS tools in the research, so as to make up for the temporary inability to supplement relevant details in the workflow figure.

 

Comments 7: Compared to the Results and Analysis section, the Methodology could be simplified to include only the most relevant details. The tables throughout the article, especially in the Methodology, are hard to read because the rows are not easy to distinguish.

Response 7:

Thank you for your valuable comment. We agree with your suggestion and will optimize the tables in the Methodology section of the article (especially Table 4 and Table 5). Specifically, we will adjust line spacing, add borders, and implement other formatting adjustments to enhance the distinction between rows. Additionally, we will define abbreviations for indicators: these abbreviations will be used to denote duplicate indicators in Table 5, ensuring consistency with the abbreviations applied to single-factor indicator evaluation in the Results section. These revisions are intended to improve the tables’ readability.

 

Comments 8: Tables of indicators need to be linked with equations to understand their relationship with the analysis and subsequent results. 

Response 8:

Thank you for your valuable comment. We agree with your suggestion. We will link the tables of indicators with the relevant equations to clearly demonstrate the relationship between the indicators, the analysis process, and the subsequent results, thereby helping readers better understand these connections. The specific revisions are asfollows:

(old version: lines 376-377)

The expression for evaluating the demand level of underground space resources in SAC (Equation 4.2)

(new version：lines 416-417)

The expression for evaluating the demand level (X) of underground space resources in SAC (Equation 4.2)

 (old version: lines 386-387)  

The expression for the underground space resource suitability evaluation mode l(Equation 4.3)

(new version：lines 426-427)

The expression for the underground space resource suitability evaluation model (Y) (Equation 4.3)

 

Comments 9: (530) Figure 8 is unclear. The elements listed in the legend are not explained in the main text.

Response 9:

Thank you for pointing this out. We agree with this comment. We will enhance the clarity of Figure 8 (new version: line 574) and explain in detail the elements listed in the legend in the optimization strategy section （6.1） to help readers better understand this figure. The specific revisions are asfollows:

(new version: lines 563-569)

Developed underground spaces requiring renewal and transformation are mainly concentrated on both sides of the development axis of the ancient city, with relatively large plot areas; those undergoing micro-update optimization are relatively scattered throughout the ancient city; and finally, underground spaces requiring transformation are relatively scarce, with only three plots located in the northern part of the ancient city. The specific spatial distribution of the three categories is shown in Figure 8

 

Comments 10: As noted in the recommendations for the introduction and literature review, the conclusions highlight the importance of “organic renewal.” It is crucial to consider this aspect in emphasizing the conclusions drawn from the authors' analysis.

Response 10:

Thank you for pointing this out. We agree with this comment. We have emphasized "organic renewal" in the conclusion section (lines 677–686) to highlight its importance and connect "organic renewal" with the analysis results. The specific revisions are as follows:

(new version: lines 677-682)

Notably, this spatial pattern corresponds closely with the "One Axis, Two Rings" framework proposed in the "14th Five-Year Plan for the Protection and Utilization of the Historic City." This indicates that integrating "organic renewal" into underground space evaluation can effectively guide the coordinated development of the conservation of ancient cities and the expansion of space.

(new version: lines 684-686)

All these measures are based on the principle of "organic renewal", avoid large-scale demolition, and accomplish the sustainable utilization of underground space.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This study aims to construct an evaluation index system for Underground Space Development Potential (USDP) in ancient cities from the perspective of organic renewal. Taking Shaoxing Ancient City as a case study, it quantitatively assesses underground space development potential through two dimensions and proposes differentiated optimized utilization strategies, thereby balancing the contradiction between ancient city preservation and efficient utilization of spatial resources. The research methodology is reasonable, and the findings have practical significance. It is suggested that the authors further improve the manuscript in the following aspects.

(1) The reliance on scoring by 6 experts to determine weights may introduce bias. The authors should verify expert weights using the entropy weight method or AHP-fuzzy comprehensive evaluation method to reduce methodological subjectivity. Alternatively, a sensitivity analysis could be added in the results section to test the impact of indicator weight changes on potential evaluation outcomes.

(2) The research data primarily comes from government departments. Existing related studies often incorporate public participation (e.g., resident demand surveys) or third-party field validation. The authors are advised to supplement the discussion with such elements or cite relevant literature for support.

(3) Ancient cities exhibit diverse types. While the proposed evaluation framework is innovative, its applicability and effectiveness in other ancient cities require further examination. A deeper discussion on the adaptability and limitations of the index system is needed.

(4) The authors should further analyze the causes of spatial mismatch between existing underground spaces and high-potential areas.

Author Response

1. Summary

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections shown in track changes in the re-submitted files. Our responses are in black, quoted text from the old version of the manuscript is in gray, and quoted text from the revised version is in red.

 

2. Questions for General Evaluation	Reviewer’s Evaluation	Response and Revisions
Does the introduction provide sufficient background and include all relevant references?	Yes
Is the research design appropriate?	Yes
Are the methods adequately described?	Can be improved
Are the results clearly presented?	Can be improved
Are the conclusions supported by the results?	Can be improved
Are all figures and tables clear and well-presented?	Yes

 

3. Point-by-point response to Comments and Suggestions for Authors

Comments 1: The reliance on scoring by 6 experts to determine weights may introduce bias. The authors should verify expert weights using the entropy weight method or AHP-fuzzy comprehensive evaluation method to reduce methodological subjectivity. Alternatively, a sensitivity analysis could be added in the results section to test the impact of indicator weight changes on potential evaluation outcomes.

Response 1:

Thank you for your valuable comment. We agree with your concern regarding methodological subjectivity. This study adopts the expert scoring method to determine indicator weights, which has been used by many scholars in existing studies related to underground space potential assessment and other relevant fields. We have listed relevant research papers in the table below for illustration.

Table 1 Evaluation Contents and Methods Related to Underground Space Development Potential

City	Site Type	Evaluation Content	Evaluation Method	References
Sanya	Central Urban Area	Development Potential	Expert Scoring and Weighting Method	Zhang Hangfei, Yu Shaowen, Wu Duoyu, et al. Potential Assessment of the Development of Underground Space Resources in Downtown Sanya City[J]. Chinese Journal of Underground Space and Engineering, 2021, 17(S1): 16-21, 39.
Beijing	Urban Central Area	Development Potential	Expert Scoring Method	Zhao Yiting.Quantitative Evaluation Research on Underground Space Development Potential in Urban Central Areas[J]. China Construction, 2019 (9): 39-41.
Yangzhou	Ancient City	Resource Quality Evaluation	Expert Scoring Method	Zhang Ping, Chen Zhilong.Evaluation on the Quality of Underground Space Resource in Historic District: A Case Study on Yangzhou Old City[J]. City Planning Review, 2012,36(11): 29-32.
Jinan	Urban Central Area	Development Demand Evaluation	Delphi Method	Qi Xiaoxing, Li Jianchun.Evaluation on Demand Degree of Urban Underground Space based on the POI Data: A Case Study in Jinan City[J]. China Land Science, 2018,32(5): 36-44.
Shanghai	Shanghai Urban Area	Development Suitability Evaluation	Expert Scoring Method	Peng Jian, Liu Kun, Zheng Futao, et al.Evaluation for the Suitability of Underground Space Exploitation and Utilization Based on AHP[J]. Chinese Journal of Underground Space and Engineering, 2010, 6(4): 688-694.

Meanwhile, to minimize subjectivity at the methodological level, the study integrates the fuzzy comprehensive evaluation method (used to unify dimensions and standardize indicators) and incorporates technical approaches commonly applied in natural resource survey and assessment (such as the element analysis and elimination method, multi-factor comprehensive assessment method, and plot unit superposition method) to improve the evaluation process.

In addition, we also fully recognize the importance of sensitivity analysis in testing the impact of changes in indicator weights on potential assessment results. We will incorporate this analysis in subsequent studies to further enhance the rigor of the research.

 

Comments 2: The research data primarily comes from government departments. Existing related studies often incorporate public participation (e.g., resident demand surveys) or third-party field validation. The authors are advised to supplement the discussion with such elements or cite relevant literature for support.

Response 2:

Thank you for pointing this out. We agree with this comment. In fact, public participation has been incorporated into this study: The "Residents' demand" indicator in the "Functional Deficiency Remedying Needs" criterion layer is based on data collected through on-site visits and interviews with residents. To better address your suggestion, we have supplemented the data source section by adding the acquisition method of the "Residents' demand" indicator, and clarified the public participation component in the research.(new version: lines 228-229)

 

Comments 3: Ancient cities exhibit diverse types. While the proposed evaluation framework is innovative, its applicability and effectiveness in other ancient cities require further examination. A deeper discussion on the adaptability and limitations of the index system is needed.

Response 3:

Thank you for pointing this out. We agree with this comment. We have supplemented the explanation of the applicability and limitations of the framework of this study to other types of ancient cities in the conclusion section (lines 693-696). The specific revisions are as follows:

(old version: lines 642-643)

This indicator system can serve as a reference for similar urban contexts in the development of underground spaces.

(new version: lines 693-696)

This indicator system can serve as a reference for the USD of ancient areas in large- and medium-sized cities with similar grades and scales, and provide certain significance for constructing of indicator systems for USD in other grades of cities.

 

Comments 4: The authors should further analyze the causes of spatial mismatch between existing underground spaces and high-potential areas.

Response 4:

Thank you for this valuable comment. We acknowledge the importance of analyzing the causes of spatial mismatch. However, this study primarily focuses on areas with high underground space potential that are yet to be developed, so developed underground space plots are not the core focus of this research. That said, in the strategy section, we have proposed targeted optimization suggestions for developed underground space plots with low efficiency to tackle relevant issues (Section 6.1).

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

I wish to commend you on the thoroughness and scientific rigor demonstrated in your manuscript. Your integration of spatial analysis data and the use of a multi-factor comprehensive evaluation method to quantify the indicators for assessing the underground space development potential, represents a robust and well-structured methodological framework.

I have the following comments and suggestions:

• Please ensure that all abbreviations are introduced in full the first time they appear in the main text, even if they have already been defined in the abstract. (USDP line 94, for example)
• Lines 89-95: The sentence is overly long and may overwhelm the reader. I suggest breaking it into shorter, clearer statements.
• Lines 123-127-130: References should be placed directly next to the corresponding author names, and the initials of first names should be omitted for consistency with citation style.
• Lines 169-174: I recommend dedicating a separate paragraph to explicitly state and elaborate more on your research questions, scope, and contribution of this study. This will strengthen the framing of your work and clarify its added value to the field.
• Line 194: Section 3.2. A table summarizing all datasets used (including their spatial resolution, acquisition date, and source) would significantly improve transparency and reproducibility.
• Figure 6(a): Please correct the typographical error “damand” to “demand”
• In the Conclusion section, you should discuss any limitations faced in your study and suggest possible directions for future work to overcome these challenges.

Author Response

1. Summary

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections shown in track changes in the re-submitted files. Our responses are in black, quoted text from the old version of the manuscript is in gray, and quoted text from the revised version is in red.

 

2. Questions for General Evaluation	Reviewer’s Evaluation	Response and Revisions
Does the introduction provide sufficient background and include all relevant references?	Yes
Is the research design appropriate?	Can be improved
Are the methods adequately described?	Yes
Are the results clearly presented?	Yes
Are the conclusions supported by the results?	Yes
Are all figures and tables clear and well-presented?	Yes

 

3. Point-by-point response to Comments and Suggestions for Authors

Comments 1: Please ensure that all abbreviations are introduced in full the first time they appear in the main text, even if they have already been defined in the abstract. (USDP line 94, for example)

Response 1:

Thank you for pointing this out. We agree with this comment. We have completed the full spellings of the abbreviations when they first appear in the introduction section (lines 106-108 and lines 114–117). The specific revisions are asfollows:

(old version: lines 94-95)

,which should be considered together to evaluate USDP especially in ancient city areas.

(new version：lines 106-108)

These factors should be considered together to evaluate underground space development potential (USDP), especially in ancient cities.

(old version: lines 101-104)

Using a multi-factor comprehensive evaluation method, ......, the evaluation of USDP in SAC was conducted.

(new version: lines 113-116)

Using a multi-factor comprehensive evaluation method,......, we evaluated the USDP of Shaoxing Ancient City (SAC) by classifying,

 

Comments 2: Lines 89-95: The sentence is overly long and may overwhelm the reader. I suggest breaking it into shorter, clearer statements.

Response 2:

Thank you for pointing this out. We agree with this comment. We have split the long sentences in the introduction section (lines 102–109) into shorter ones. The specific revisions are asfollows:

(old version: lines 89-95)

At present, most researches on the development of underground space resources at home and abroad primarily focus on the engineering factors such as engineering geology, hydrogeology, site stability, geological disasters, topography and geomorphology[19][20], while factors related to organic renewal are somehow neglected like ecological sensitivity, historical and cultural protection, the situation of existing underground space, overground construction conditions and land use, which should be considered together to evaluate USDP especially in ancient city areas.

(new version：lines 101-108)

At present, most studies on the development of underground space resources both at home and abroad primarily focus on engineering-related factors such as engineering geology, hydrogeology, site stability, geological disasters, topography, and geomorphology[21][22]. However, factors related to organic renewal, such as ecological sensitivity, historical and cultural protection, the current status of underground spaces, overground construction conditions, and land use have been neglected. These factors should be considered together to evaluate underground space development potential (USDP), especially in ancient cities.

 

Comments 3: Lines 123-127-130: References should be placed directly next to the corresponding author names, and the initials of first names should be omitted for consistency with citation style.

Response 3:

Thank you for pointing this out. We agree with this comment. We have directly labeled the references in the literature review section (lines 142-150, 177-183) immediately after the corresponding authors, and revised the presentation of the authors' names. The specific revisions are asfollows:

(old version: lines 123-127-132,160-166)

For example, Sterling R L et al. summarized ....... that can be effectively utilized[23]. Youssef A M et al. conducted a suitability ...... potential engineering geological hazards on underground projects[24]. Doyle M R studied the city of San Antonio and Texas ...... corresponding resource potential map[25].

Zhang established an evaluation system ...... such as cultural relics protection[34]. Wang constructed an index system from ...... historical and cultural blocks in Tianjin City, China[35]. Zhu analyzed multiple influencing ...... for USD[36].

(new version：lines 142-150,177-183)

For example, Sterling et al[27] summarized ...... that can be effectively utilized. Youssef et al[28] conducted a suitability ...... potential engineering geological hazards on underground projects. Doyle[29] studied the city of San Antonio and Texas ...... corresponding resource potential map.

For example, Sterling et al.[27] summarized ....... that can be effectively utilized. Youssef et al.[28] conducted a suitability ...... hazards on underground projects. Doyle[29] studied the city of San Antonio, Texas ......  corresponding resource potential map.

Zhang[38] established a system ...... such as cultural relics protection. Wang[39] constructed an index system ...... historical and cultural blocks in Tianjin City, China. Zhu[40] analyzed multiple influencing ...... methods for USD.

 

Comments 4: Lines 169-174: I recommend dedicating a separate paragraph to explicitly state and elaborate more on your research questions, scope, and contribution of this study. This will strengthen the framing of your work and clarify its added value to the field.

Response 4:

Thank you for pointing this out. We agree with this comment. We have reorganized the literature review section (lines 187–203) into a new paragraph and expanded it from the perspectives of existing issues in previous studies, research scope, and research contributions. The specific revisions are asfollows:

(new version：lines 187-203)

To summarize, while existing studies on urban USDP have laid a certain foundation in terms of evaluation methods and engineering indicators, research related to organic renewal has also confirmed its significance in ancient city protection by emphasizing incremental, heritage-respecting renewal models. However, three key gaps remain in current research: first, most USDP evaluations prioritize engineering feasibility but overlook demand factors derived from organic renewal; second, studies mostly focus on small-scale areas such as historical and cultural blocks, lacking systematic evaluations at the scale of an entire ancient city; and third, the integration of organic renewal concepts into USDP evaluation frameworks is insufficient. Against this backdrop, this study takes SAC—a national-level historical and cultural city with limited above-ground development space and an urgent need for organic renewal—as its research object. Focusing on an entire ancient city and using the demands of urban organic renewal as a guide, this study integrates multi-factor comprehensive and fuzzy evaluation methods to construct a new evaluation framework for USDP. We conduct corresponding empirical research using GIS spatial analysis technology, ultimately providing scientific references for the development and utilization of underground space in the study area and other similar ancient cities.

 

Comments 5: Line 194: Section 3.2. A table summarizing all datasets used (including their spatial resolution, acquisition date, and source) would significantly improve transparency and reproducibility.

Response 5:

Thank you for pointing this out. We agree with this comment. We have added a summary table of datasets to the data source section (Section 3.2) to present data information more clearly (new version：lines 230). The specific table is as follows:

Table 2 Summary of USDP data evaluation.

Data	Spatial resolution	Acquisition date	Data sources
Lland use data	Vector Data	2022	Natural Resources and Planning Bureau of Shaoxing City
Engineering hydrological	Raster Data (5m*5m)	2020
Geological data	Raster Data (5m*5m)	2020
Current underground space data	Vector Data	2022
Building boundary data	Vector Data	2022
Road network data	Vector Data	2022

 

Comments 6: Figure 6(a): Please correct the typographical error “damand” to “demand”

Response 6:

Thank you for pointing this out. We agree with this comment. We have corrected "damand" to "demand" in Figure 6(a). The specific revisions are asfollows:

(old version: lines 445)

(new version：lines 484)

Comments 7: In the Conclusion section, you should discuss any limitations faced in your study and suggest possible directions for future work to overcome these challenges.

Response 7:

Thank you for pointing out this issue. We agree with this comment. We have supplemented and refined the limitations of this study from two aspects, namely the research depth of underground space and the evaluation indicator system, in the conclusion section (Lines 697–712), and proposed key research directions for overcoming challenges in the future. The specific revisions are as follows:

Regarding the research depth of underground space, we have clearly elaborated on the dual constraints of requirements for ancient city protection and current engineering technology, which have led this study to focus only on the depth range of 0 to -30 meters within the SAC (new version：lines 699-702). In response to this limitation, we have proposed that future research will focus on exploring "adaptive vertical stratification methods suitable for ancient city scenarios" to balance the assessment of development potential of deeper underground space and cultural heritage protection (new version：lines 702-705).

With regard to the evaluation indicator system, we have clarified the current deficiencies: insufficient foundational data and unscientific methods for determining indicator weights. These result in the system’s inability to fully capture the mutual influences between different plots and make it difficult to quantify some specialized indicators (like key land for renewal, ecological protection targets) accurately  (new version：lines 705-709). To address these issues, we have emphasized that future research will prioritize integrating multi-source data (including high-resolution geological surveys and cultural heritage monitoring datasets) to enrich data sources, and optimize methods for determining weights, thereby enhancing the rigor and practicality of the indicator system (new version：lines 709-712).

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thanks for considering my observations and suggestions. The article has greatly improved in its contents. Clarifying "organic renewal" as a way to identify hidden historical environments is a crucial addition to preserving these methods for use in urban policies. The case study of Shaoxing Ancient City can be replicated in other cases as a way to identify and delineate preservation zones. 

The following formal recommendations are outlined below: 

1. Please check reference errors in lines 45 and 59.

2. Take a look at the following Tables, which have been cut along pages:

   1. Table 1 (pages 5-6, 224)

   2. Table 5 (pages 10-11, 396)

   3. Table 7 (page 12-13,  429).

   4. Table 10 (page 19-20, 595).
3. Check the format of space on page 13 (437)

 

Author Response

1. Summary

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections shown in track changes in the re-submitted files. Our responses are in black.

2. Questions for General Evaluation	Reviewer’s Evaluation	Response and Revisions
Does the introduction provide sufficient background and include all relevant references?	Yes
Is the research design appropriate?	Yes
Are the methods adequately described?	Yes
Are the results clearly presented?	Yes
Are the conclusions supported by the results?	Yes
Are all figures and tables clear and well-presented?	Must be improved

3. Point-by-point response to Comments and Suggestions for Authors

Comments 1: Please check reference errors in lines 45 and 59.

Response 1:

Thank you for pointing this out. We agree with this comment. We have carefully checked the references cited in the paper and made revisions in lines 46 and 60.

 

Comments 2: Take a look at the following Tables, which have been cut along pages:

Table 1 (pages 5-6, 224)；Table 5 (pages 10-11, 396)；Table 7 (page 12-13,  429)；Table 10 (page 19-20, 595).

Response 2:

Thank you for pointing this out. We agree with this comment. We have adjusted all tables in the paper to ensure that most tables are displayed on a single page and reduce page breaks. In addition, we have uploaded the PDF version of the revised manuscript to avoid any formatting changes that may be caused by uploading or downloading the Word document in the system.

 

Comments 3: Check the format of space on page 13 (437)

Response 3:

Thank you for pointing this out. We agree with this comment.The spacing issue appearing in Line 446 is actually caused by the excessively large paragraph spacing setting for figure captions. Regarding this issue, we have conducted unified review and standardization of the settings for all figure-related paragraphs in the paper, to ensure they strictly comply with the journal’s formatting specifications.

Author Response File: Author Response.pdf