A Model of Building Changes to Support Comparative Studies and Open Discussions on Densification

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

(1) This paper proposes a collaborative platform to support the generation of building change maps from different building data sources and the clarification of related concepts. However, this is merely a theoretical model, or more like a technical engineering process or framework. What are the innovative points in it? And how does it solve the problem of building changes?
(2) The operability of the methods described in the article is debatable. The author states in the article that local data experts analyze building data sources. First, it is necessary to identify the data sources, which is usually done through email communication. But it is not described in the article how to determine the recipients of these emails, nor their authority and the timeliness of processing. However, these are also matters that need to be considered for map updates.

Author Response

Comment (1) This paper proposes a collaborative platform to support the generation of building change maps from different building data sources and the clarification of related concepts. However, this is merely a theoretical model, or more like a technical engineering process or framework. What are the innovative points in it? And how does it solve the problem of building changes?

Answer (1) Indeed, our proposal is still on-going work and encompasses a large framework to engineer data and metadata.

We try to address two problems : (1) the lack of convenient tools to support an informed dialogue about densification between actors with different background. (2) the difficulty to model building changes in a systematic way connected to evidence. 

We hope to contribute with two innovative points. First aspect is to describe topographic changes at the level of entities in a systematic way, on a relevant spatial scale and in a comparable way. We proposed an innovative method and applied it to yield three datasets. A second innovative point is to propose a collaborative environment to allow collaboration between experts who can express relevant questions about densification and experts who can process data. 

Comment (2) The operability of the methods described in the article is debatable. The author states in the article that local data experts analyze building data sources. First, it is necessary to identify the data sources, which is usually done through email communication. But it is not described in the article how to determine the recipients of these emails, nor their authority and the timeliness of processing. However, these are also matters that need to be considered for map updates.

Answer (2) We will try to make it clearer in the paper. Our proposal does not target the quick identification of datasource but rather to share feedbacks so that once a researcher has investigated the relevance of a given product, a researcher who wish to work with the same product can rely on his expertise.

This has been performed based on the network of the authors : contact within the french mapping agency, contact at the University. Indeed this identification is not detailed. Our proposal does not target the quick identification of these experts, rather we intend to share the knowledge about data that we have acquired through these contacts. Each scientist that has already experience working with national data can contribute by identifying the authorities. Google dataset search and INSPIRE portal can also help to identify relevant providers. Once a provider is identified, a geomatician reads and explores the documentation on his website, but as you point out it is always necessary to engage with production teams. In some cases we have contacts within production teams as at IGN and in that case we have access to more experts. During the full workflow, contacting specific people is also done through calls, but we try and use the git to keep a log about important decisions and to consolidate informationinfirmation about the data we process, 

Reviewer 2 Report

Comments and Suggestions for Authors

This article presents a compelling investigation into the production of building change maps as tools for understanding urban densification. The methodology is robust and innovative, leveraging collaborative dashboards and data matching algorithms to process building changes across diverse urban contexts. However, the paper requires refinement in clarity and narrative flow, particularly in aligning findings with objectives, providing a more structured discussion, and explicitly addressing limitations. Overall, the study is promising and merits publication after major revisions.

Comments for author File: Comments.pdf

Author Response

Please see attachement

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

Dear colleagues, thank you for your valuable contribution on a building changes model to support comparative studies on densification. From the introduction I understand the aim of the paper to contribute to the topic of urban and suburban densification, affordable housing and potential resistance to densification. 

I liked the approach of embedding the European SDI, of evaluating different data sources from different countries and therefore highlighting the effects of different maintenance procedures, like in figure 2, which shows that not all visible changes in data base on actual changes of entities in nature. Cross-border approaches are difficult to handle but are essential for solving European questions. 

Allow me to highlight some issues I have been missing: 

(1) Data integration: Although for the geospatial data different sources (landcover, aerial imaging, surveying) were considered, I am missing a real data-integration perspective. This perspective allows for cross-checking data qualities and could enhance the presented model. E.g. considering statistical registers which own information about "registered persons at the place of residence" or the "dwelling register", which includes floors of a building, could enormously support the question of changes in urban and suburban densification, which cannot be solely solved by geospatial information. An integrative approach of geospatial and thematic data sources is key. The authors mention a fist step to "data integration" in the "discussion and perspectives" section in line 745ff with "additional data must be used to detect changes".  It could be mentioned and highlighted earlier in the contribution. 

(2) Ontologies: in section 2.3.1. from line 287ff the authors highlight the importance of semantics and refer to the semantic web community. The proposed approach refers to wikidata and its ontology. For me the question arises if alternative ontologies, like dbpedia or schema.org should be considered, at least mentioned in the contribution?!

(3) In section 2.3.3. in line 339 the DOLCE ontology is mentioned. As reader any understanding is missing at this point and a short explanation would be helpful. 

(4) In the description of the "proposal" in section 3, the notion "densification expert" is used. At this point the qualities and skills of a densification expert is unclear. Is it something like an urban planner or geodetic person, or is it a broker, who knows about different data sources? A short description would be helpful to understand this role. 

I hope you understand my comments as helpful support and once again thank for your valuable contribution. 

 

 

 

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors I have revised all the questions I raised, and I have no more questions.      

Reviewer 2 Report

Comments and Suggestions for Authors

I thank the authors for taking all my suggestions into account and making corrections. It is suitable for publication in this form.