Formulation of Urban Growth Scenarios for Middle-Sized Cities Towards Metropolization: The Case of Puerto Montt, Los Lagos Region

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. The study proposes to set up three scenarios, but the results of the simulation of the three scenarios and the analysis of the differences between them, the comparative analysis of the absolute entropy of the three scenarios, as well as the recommendations for land use optimisation are not sufficiently explained in the article.
2、 The abstract lacks quantitative data support and a specific summary of the results of the three scenarios.
3. Need to explain why the PLUS model was chosen instead of CLUE, FLUS and other models.
4、 What is the basis for the three scenarios?

Author Response

Comments 1: The study proposes to set up three scenarios, but the results of the simulation of the three scenarios and the analysis of the differences between them, the comparative analysis of the absolute entropy of the three scenarios, as well as the recommendations for land use optimisation are not sufficiently explained in the article.
Reply: Further background information is provided, although we do not wish to extend the text, considering that some aspects of the modeling have already been validated and applied by other works of the scientific community.
Comments 2: The abstract lacks quantitative data support and a specific summary of the results of the three scenarios. Reply: This section has been improved.
Comments 3: Need to explain why the PLUS model was chosen instead of CLUE, FLUS and other models.
Reply: New section “Background” is added where we highlight these points. Thank you for your suggestions.
Comments 4: What is the basis for the three scenarios? Reply: The three scenarios were proposed theoretically, within the framework of strategic planning and according to a vision of a more sustainable city construction, with protection in areas of high ecological value and the existence of current planning instruments. A pessimistic Business-As-Usual (BAU) scenario (S1), a tendency scenario (Urban-Regional Planning (S2) and an optimistic Conservationist scenario (S3) were proposed.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors, the article is clear and the research well described.

Your research is highly topical with regard to the formulation of predictive scenarios on the development of an area. Certainly, the adoption of such methodologies suitably refined can provide a predictive tool on land use and thus guide policy choices.  To make the methodology generalisable, it would be interesting to apply it to other contexts (other countries). 

I suggest reviewing the graphic quality of figure 2 (resolution and colour scheme), figure 3 and figure 5 (the quality is not adequate for a magazine, change graphics and layout).

 

Author Response

Comments 1: 

Dear authors, the article is clear and the research well described.

Your research is highly topical with regard to the formulation of predictive scenarios on the development of an area. Certainly, the adoption of such methodologies suitably refined can provide a predictive tool on land use and thus guide policy choices.  To make the methodology generalisable, it would be interesting to apply it to other contexts (other countries). 

I suggest reviewing the graphic quality of figure 2 (resolution and colour scheme), figure 3 and figure 5 (the quality is not adequate for a magazine, change graphics and layout).

Reply: Due to time constraints, it was not possible to modify the quality and size of figures 3 and 5. Figure 2 comes from a secondary source, and for this reason it is not possible to modify it. However, an improvement has been made in several sections of the article.

Reviewer 3 Report

Comments and Suggestions for Authors

1. The introduction cites a large amount of literature but lacks an in-depth review of existing research. Could the authors further elucidate in what ways existing studies are inadequate, thereby highlighting the innovative points of this study? What specific studies have attempted to model land use change in medium-sized cities? What are the limitations of these studies?
2. The hypothesis mentions “low-density decentralized development” but does not explain why 2050 was chosen as the time point. Is there any historical data that suggests an acceleration of this trend? Alternatively, the time span of the scenario modeling needs to be justified.
3. It is mentioned that LCZ classification and concentric circle modeling will be used, but there is no justification for the choice of these methods, and a comparative study of the methods needs to be cited.

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

Comments 1: The introduction cites a large amount of literature but lacks an in-depth review of existing research. Could the authors further elucidate in what ways existing studies are inadequate, thereby highlighting the innovative points of this study? What specific studies have attempted to model land use change in medium-sized cities? What are the limitations of these studies?  Reply: The existing review is expanded to include a background section.

Comments 2: The hypothesis mentions “low-density decentralized development” but does not explain why 2050 was chosen as the time point. Is there any historical data that suggests an acceleration of this trend? Alternatively, the time span of the scenario modeling needs to be justified. Reply: Section 2. Background incorporates a brief discussion of the importance of simulating long periods, and shows an example using the PLUS model to simulate to 2050.

Comments 3: It is mentioned that LCZ classification and concentric circle modeling will be used, but there is no justification for the choice of these methods, and a comparative study of the methods needs to be cited. Reply: References are added in the method alluding to other works.

Reviewer 4 Report

Comments and Suggestions for Authors

The manuscript presents a simulation of land use and land cover changes projected to the year 2050 for the intermediate city of Puerto Montt, identifying three temporal milestones: 1988, 2005, and 2020. These are characterized using the Local Climate Zones (LCZ) method, and the study integrates the PLUS (Patch-generating Land Use Simulation) model to simulate urban growth scenarios. The experiment appears robust and well-argued, detailing the research steps in a sufficiently replicable manner, albeit not always with full methodological transparency. The use of the PLUS model—already validated by the scientific community—constitutes an innovation within this context and may pave the way for further lines of inquiry. Moreover, the model could support policy makers in strategic urban transformation decisions, and legislators in addressing current regulatory shortcomings.

The introductory section effectively outlines the cultural and planning context underlying the study's premises. However, the manuscript would benefit from the addition of a background section (possibly to be developed within Sections 2 or 3). Specifically, the inclusion of a section that reviews the current global landscape of studies concerning urban transformation forecasting and scenario analysis would enhance the theoretical grounding of the paper. While the analytical argument is clearly articulated and the experimental approach is solid, the theoretical framework within which this contribution is situated appears somewhat underdeveloped. It is therefore recommended that the authors consider the inclusion of a dedicated background section aimed at addressing this gap.

It is also suggested that Section 2, which currently describes the case study, be incorporated as a sub-section within Section 3. The case study represents the empirical foundation of the experiment and would logically fall within the methodological framework. In turn, Section 2 could then be dedicated to the cultural and theoretical background, helping to delineate the conceptual and investigative domain of the research. For example, in Subsection 3.2.2, the authors rightly highlight that land use and land cover change (LULC) models are widely appreciated in geographic and urban studies. Such an observation would be strengthened by a dedicated background section offering a more comprehensive overview of the scholarly consensus, supported by a wider range of references.

In the "Materials and Methods" section, the authors note that 9 out of the 17 LCZ classes were selected and validated through field surveys conducted in January 2021 and via literature review concerning other medium-sized Chilean cities. For purposes of verification and potential replication, it would be important to cite the specific literature sources reviewed. These could be included in an appendix if the authors prefer not to expand the main text further.

To enhance the impact of the results discussion presented in Section 5, the positions described could be compared with the broader theoretical stances currently held by urban planning scholars internationally. This could help determine whether the building typologies shown to be expanding over time align with sustainable territorial development principles, particularly in light of the current climate crisis. While this observation may seem tangential to the paper’s primary scope, it is respectfully submitted for the authors’ consideration—perhaps as a topic for a future stage of the research. It should be emphasized that this comment does not detract from the rigor and seriousness of the work presented. Rather, such a comparison would also clarify the environmental impacts alluded to in the conclusions, which are currently referenced in general terms.

Finally, the conclusions section appears rather succinct in relation to the comprehensive nature of the work carried out. It would be appropriate for the authors to advocate more explicitly for specific policy recommendations, particularly in light of the projected scenarios. Such an addition would strengthen the practical applicability of the study and provide valuable guidance to decision-makers.

Author Response

Comments 1:  The introductory section effectively outlines the cultural and planning context underlying the study's premises. However, the manuscript would benefit from the addition of a background section (possibly to be developed within Sections 2 or 3). Specifically, the inclusion of a section that reviews the current global landscape of studies concerning urban transformation forecasting and scenario analysis would enhance the theoretical grounding of the paper. While the analytical argument is clearly articulated and the experimental approach is solid, the theoretical framework within which this contribution is situated appears somewhat underdeveloped. It is therefore recommended that the authors consider the inclusion of a dedicated background section aimed at addressing this gap. Reply:  The "Background” section has been added to address this question. In the introduction, the gap of this study has been made even more explicit. 

Comments 2: It is also suggested that Section 2, which currently describes the case study, be incorporated as a sub-section within Section 3. The case study represents the empirical foundation of the experiment and would logically fall within the methodological framework. In turn, Section 2 could then be dedicated to the cultural and theoretical background, helping to delineate the conceptual and investigative domain of the research. For example, in Subsection 3.2.2, the authors rightly highlight that land use and land cover change (LULC) models are widely appreciated in geographic and urban studies. Such an observation would be strengthened by a dedicated background section offering a more comprehensive overview of the scholarly consensus, supported by a wider range of references. Reply: This suggestion was considered. Thank you.

Comments 3: In the "Materials and Methods" section, the authors note that 9 out of the 17 LCZ classes were selected and validated through field surveys conducted in January 2021 and via literature review concerning other medium-sized Chilean cities. For purposes of verification and potential replication, it would be important to cite the specific literature sources reviewed. These could be included in an appendix if the authors prefer not to expand the main text further. Reple: The corresponding sources have been added. See line 188. 

To enhance the impact of the results discussion presented in Section 5, the positions described could be compared with the broader theoretical stances currently held by urban planning scholars internationally. This could help determine whether the building typologies shown to be expanding over time align with sustainable territorial development principles, particularly in light of the current climate crisis. While this observation may seem tangential to the paper’s primary scope, it is respectfully submitted for the authors’ consideration—perhaps as a topic for a future stage of the research. It should be emphasized that this comment does not detract from the rigor and seriousness of the work presented. Rather, such a comparison would also clarify the environmental impacts alluded to in the conclusions, which are currently referenced in general terms. Reply: In section 5.2. Potential impacts of the predicted LULC changes, a new paragraph has been added to incorporate a comparison with other trends in urban planning in Latin America. Thank you for the suggestion.

Finally, the conclusions section appears rather succinct in relation to the comprehensive nature of the work carried out. It would be appropriate for the authors to advocate more explicitly for specific policy recommendations, particularly in light of the projected scenarios. Such an addition would strengthen the practical applicability of the study and provide valuable guidance to decision-makers. Reply: The conclusions section is improved by indicating which is the most favorable scenario and possible socioeconomic and environmental consequences for each scenario. Thank you for the suggestion.

 

 

Reviewer 5 Report

Comments and Suggestions for Authors

The authors elaborate a study on forecasts for land use and land cover changes for 2050 for intermediate city of Puerto Montt, Chile. The study includes long-term observations with key points in 1988, 2005, and 2020. Three scenarios were elaborated - Business-As-Usual, Urban-Regional Planning, and Conservationist. The authors well ground necessity to forecast changes in land use and land cover. In addition, benefits of the specificity of the urban system selected for the study is explained. The authors explain steps of research and clearly visualize results. The authors highlight that forecasting approach may help to manage the process that during the last decades went outside the scope of planning. The research results have high practical importance. The scenarios in their sense offer different development possibilities. The authors apply approach that is novel to the case of city in Chili as indicated in the text (see lines 433-434). The authors demonstrate wide knowledge in the theme. The reviewer indicates some points for possible improvements:

1) In Introduction, the thematic focus is well described but background of previous research is not provided and research gap is not defined.

2) The Section 2 is too short. It does not provide description of economic functionality peculiarities and previous activities of the urban system, which stimulated changes during last decades.

3) The authors do not indicate which scenario is more favorable; do not provide possible socioeconomic and environmental consequences, characteristics for each scenario.

4) The literature may be expanded with some newest sources for demonstrating current trends in the theme.

Comments on the Quality of English Language

It is recommended to check English grammar and style. For example, see line 461 - "to also understand".

Author Response

Comments 1: In Introduction, the thematic focus is well described but background of previous research is not provided and research gap is not defined. Reply: This point was reordered, leaving explicitly the gap that this study intends to resolve. See lines 78-80 and 88-90.

Comments 2: The Section 2 is too short. It does not provide description of economic functionality peculiarities and previous activities of the urban system, which stimulated changes during last decades. Reply: The old section 2 "Study area" has been moved to section three. The case study represents the empirical foundation of the experiment and would logically fall within the methodological framework. 
In addition, a new section 2 "Background" has been added, which allows to better argue the use of computational tools and GIS for spatial simulations.

Comments 3: The authors do not indicate which scenario is more favorable; do not provide possible socioeconomic and environmental consequences, characteristics for each scenario. Reply: In response to this point, the "Conclusions" section will be improved. Thank you for your suggestion.

Comments 4: The literature may be expanded with some newest sources for demonstrating current trends in the theme. Reply: We incorporate some recent articles, but there are no new studies for Chile. We believe that for this reason, this article is relevant to expand the knowledge in the use of these tools.

In general, English grammar has been improved. 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The introduction needs to be further optimised.

Author Response

Comments 1: The introduction needs to be further optimised.
Reply: This comments was solved. Thank you. 

Reviewer 3 Report

Comments and Suggestions for Authors

The author did not give an enumerated answer to my question, but the content of the article was revised accordingly. I do not have any further comments or suggestions to improve this document.

Author Response

Comment 1: The author did not give an enumerated answer to my question, but the content of the article was revised accordingly. I do not have any further comments or suggestions to improve this document.
Reply: Thank you for your comments. Anyway, the article was improved in several sections.