Assessing the Economic and Environmental Impacts of Anaerobic Digestion for Municipal Organic Waste: A Case Study of Minamisanriku Town, Japan

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The research presented in this paper is very interesting and meaningful, but the paper tries to cover too many aspects, lacking a clear main theme.

Figures:

• There should be a better description for the images, such as adding more context to Figure 1 to describe the study area.
• The image quality is insufficient; Figures 1, 2, 3, 4, 5, and 6 are very blurry when enlarged. It is recommended to use vector graphics.

Scenarios:

• The research is fascinating, and the data volume is substantial. However, the scenario settings are difficult to understand, making the paper hard to read. A comprehensive diagram summarizing all scenarios would help readers grasp the concepts more easily.
• I do not recommend using scenario codes like S1-1, S2-1, S1-2C, S1-2L, etc., as they are challenging for first-time readers. It is better to use simpler codes like A1, A2, A3, and B1, B2, B3. This is not mandatory; you can reconsider it by referring to other papers.
• In future research, consider incorporating sensitivity analysis into your study; it would be even better if you could include it in this paper.

Tables:

• Table 2 is informative but difficult to read. It might be better to move it to the appendix. It could also be split into two tables to improve readability and make it easier to read horizontally rather than vertically.

Content Focus:

• The main content of the paper exceeds what is covered in the abstract. Sections 4.4, 5.1, 5.2, and 6 can be simplified. The paper should focus on scenario analysis, with the discussion and conclusions centered on scenario differences.
• Sections 4.4, 5.1, 5.2, and 6 contain valuable suggestions for related industries, which could be expanded into a separate paper. You might use theories such as socio-technical transitions to describe the micro-level utilization of anaerobic digestion technology in Japan. Alternatively, you could combine survey results with local policies for policy research.
• Since the study involves semi-structured interviews, consider using software like Nvivo to process text data and uncover potential themes if you have recordings or notes.

References:

• There are too few references, and they are not comprehensive enough. It is necessary to reconsider the references and add sufficient related literature.

Future Research:

• Future surveys should consider using the Likert scale method, allowing for the analysis of survey data using structural equation modeling or similar techniques.

Author Response

We appreciate the time and effort you have invested in reviewing our manuscript and providing insightful comments. We have carefully considered each of your suggestions and have made the necessary revisions to improve the clarity, depth, and overall quality of the paper. Below, we detail the changes made in response to each comment.

Reviewer 1

The research presented in this paper is very interesting and meaningful, but the paper tries to cover too many aspects, lacking a clear main theme.

Response: Thank you for your valuable comments. We have carefully revised the manuscript to address your concern. Specifically, we have:

• Clarified the main theme: We have refined the focus of the paper to emphasize the key theme of assessing the economic and environmental impacts of anaerobic digestion for municipal organic waste in Minamisanriku Town, Japan.
• Streamlined the content: We have removed Section 4.4 and simplified Sections 5.1, 5.2, and 6 to ensure that the content is more concise and directly aligned with the main theme.
• Enhanced readability: We have reorganized the scenarios and provided a summary table (Table 2) to make the analysis more comprehensible.
• Focused Discussion: The discussions have been focused on the core findings and their implications, reducing extraneous details.

These changes aim to provide a clearer and more cohesive narrative, enhancing the overall coherence and impact of the manuscript.

Figures:

• There should be a better description for the images, such as adding more context to Figure 1 to describe the study area.

Response: We added a detailed description for Figure 1 on page 3, lines 107-119, as follows.

“Minamisanriku Town, the focus of this study, is located on the northeastern coast of Miyagi Prefecture in the Tohoku region of Japan (Figure 1, left), with a population of 11,496 in 2024. The map on the right of Figure 1 provides a detailed land use classification of Minamisanriku in 2016. Different colors are used to represent various land use types. The map illustrates the preponderance of forested areas (depicted in green) and the distribution of land designated for agricultural and urban use. The proximity of the town to the coastline and the presence of various land types provide insight into the socio-economic and environmental context relevant to the study of anaerobic digestion for municipal organic waste. Forested areas (green) account for nearly 80% of the land, agricultural land (brown) covers approximately 6% (around 1,000 hectares), and urban areas (red and orange) represent about 5%. Including other areas such as submerged regions and wasteland (yellow), there is a potential to utilize liquid fertilizer (digestate from anaerobic digestion) on over 2,000 hectares of land.”

 

• The image quality is insufficient; Figures 1, 2, 3, 4, 5, and 6 are very blurry when enlarged. It is recommended to use vector graphics.

Response:　Thank you for your valuable feedback regarding the image quality of Figures 1, 2, 3, 4, 5, and 6. Based on your suggestions, we have improved the image quality as much as possible in the revised manuscript. Additionally, high-resolution versions of the original graphics are available upon request.

Scenarios:

• The research is fascinating, and the data volume is substantial. However, the scenario settings are difficult to understand, making the paper hard to read. A comprehensive diagram summarizing all scenarios would help readers grasp the concepts more easily.

Response: We added Table 2 to summarize all scenarios, making them easier to understand.

Table 2 Scenario setting

Scenarios	Operating ratio	Contents
Scenario A-1. (SA-1)	56%.	In the absence of BIO facilities (control)
Scenario A-2. (SA-2)		BIO facilities in operation; no liquid fertiliser use
Scenario A-3. (SA-3)		BIO facilities in operation; liquid fertiliser utilisation (BAU)
Scenario B-1. (SB-1)	100%	In the absence of BIO facilities (control)
Scenario B-2. (SB-2)		BIO facilities in operation; no liquid fertiliser use
Scenario B-3. (SB-3)		BIO facilities in operation; use of liquid fertilisers.
Scenario B-4. (SB-4)		BIO facilities in operation; no liquid fertiliser use; power generation (ideal value)
Scenario B-5. (SB-5)		BIO facilities in operation; use of liquid fertiliser; power generation (ideal value)

 

• I do not recommend using scenario codes like S1-1, S2-1, S1-2C, S1-2L, etc., as they are challenging for first-time readers. It is better to use simpler codes like A1, A2, A3, and B1, B2, B3. This is not mandatory; you can reconsider it by referring to other papers.

Response: Simplified scenario codes to A1, A2, A3, B1, B2, B3, B4, and B5 based on your suggestion.

 

• In future research, consider incorporating sensitivity analysis into your study; it would be even better if you could include it in this paper.

Response:　Thank you so much for your valuable suggestions. We plan to incorporate sensitivity analysis in a future paper.

Tables:

• Table 2 is informative but difficult to read. It might be better to move it to the appendix. It could also be split into two tables to improve readability and make it easier to read horizontally rather than vertically.

Response: We separated Table 2 into three parts ((a)Volume/amount of material flow in scenario; (b) Expense and income; (c) GHG emission factor) for better readability, and also move it to the appendix as Table S1.

 

Content Focus:

• The main content of the paper exceeds what is covered in the abstract. Sections 4.4, 5.1, 5.2, and 6 can be simplified. The paper should focus on scenario analysis, with the discussion and conclusions centered on scenario differences.
• Sections 4.4, 5.1, 5.2, and 6 contain valuable suggestions for related industries, which could be expanded into a separate paper. You might use theories such as socio-technical transitions to describe the micro-level utilization of anaerobic digestion technology in Japan. Alternatively, you could combine survey results with local policies for policy research.

Response: Based on your suggestions, we deleted Section 4.4 and simplified Sections 5.1, 5.2, and 6.

• Since the study involves semi-structured interviews, consider using software like Nvivo to process text data and uncover potential themes if you have recordings or notes.

Response: We will consider using software like Nvivo for text data analysis in future studies.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

1.        Why Anaerobic digestion (AD) is the optimal technology?

2.        A clear Figure 3 should be given out.

3.        MOW should use abbreviations after its first adoption.

4.        The main topics covered in the interviews in the sub-section 3.3 should be given in table format.

5.        Equation numbering needs to be done according to the specifications.

6.        In Figure 5, What does negative value mean?

7.        What is the future development prospect of AD?

Comments on the Quality of English Language

Minor editing of English language required

Author Response

Why is Anaerobic Digestion (AD) the optimal technology?

Response: AD is considered optimal due to its ability to effectively treat municipal organic waste (MOW), producing biogas and nutrient-rich digestate, thus contributing to energy recovery and waste minimization. It aligns well with circular economy principles and offers environmental benefits such as greenhouse gas reduction and improved waste management.

 

A clear Figure 3 should be given out.

Response: We have revised Figure 3 to enhance its clarity and readability.

MOW should use abbreviations after its first adoption.

 

Response: We have ensured that "municipal organic waste" is abbreviated as "MOW" consistently throughout the manuscript after its first mention.

 

The main topics covered in the interviews in sub-section 3.3 should be given in table format.

Response: We prefer to keep it as the current style.

 

Equation numbering needs to be done according to the specifications.

Response: We have reviewed and updated the equation numbering to ensure compliance with the required specifications.

 

In Figure 5, what does the negative value mean?

Response: Negative values in Figure 5 indicate net environmental benefits, such as greenhouse gas emission reductions or energy savings, achieved through the implementation of AD compared to baseline scenarios.

 

What is the future development prospect of AD?

Response: The future development prospects of AD include technological advancements for increased efficiency, integration with renewable energy systems, and wider adoption in urban and rural settings for sustainable waste management.

 

Thank you again for your positive and constructive comments and suggestions on our manuscript. We have tried our best to improve the manuscript and made some changes in manuscript. We appreciate for your warm work earnestly, and really hope that the correction will meet with approval.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The current study's research objective is to assess the economic and environmental impacts of anaerobic digestion for municipal organic waste. The objective is well-formulated as it clearly states the purpose of the research, which is to evaluate the benefits of utilizing anaerobic digestion technology in a specific area. Nevertheless, the research objective does not explicitly address a particular research gap. The authors should address an existing research gap to strengthen the research objective.

The article references scientific literature, such as studies on anaerobic digestion technologies, life cycle assessments, and sustainable waste management practices. They provide a good foundation for the research and support the study's methodology and findings. However, the scientific literature analysis in the article could be more comprehensive, including a more detailed discussion of previous studies on anaerobic digestion for municipal organic waste treatment, containing analysis of different approaches and outcomes, etc. The article could strengthen its theoretical framework by improving the scientific literature analysis in these ways.

The methodology applied in the study involves a Life Cycle Assessment, stakeholder interviews, and scenario analysis. The methodology is appropriate for the research objective of assessing the economic and environmental impacts of anaerobic digestion in a specific location. I suggest the authors conduct a sensitivity analysis to test the robustness of the results under different assumptions to strengthen the validity of the findings.

The main conclusions drawn from the study are significant and based on the research analysis. Nevertheless, the authors should include a discussion of the limitations or uncertainties in the findings to enhance the transparency and reliability of the conclusions. They should also offer recommendations for policymakers, waste management authorities, and other stakeholders to provide practical guidance.

I recommend publishing the article after the authors have revised it according to the recommendations above.

Author Response

We appreciate the time and effort you have invested in reviewing our manuscript and providing insightful comments. We have carefully considered each of your suggestions and have made the necessary revisions to improve the clarity, depth, and overall quality of the paper. Below, we detail the changes made in response to each comment.

The current study's research objective is to assess the economic and environmental impacts of anaerobic digestion for municipal organic waste. The objective is well-formulated as it clearly states the purpose of the research, which is to evaluate the benefits of utilizing anaerobic digestion technology in a specific area. Nevertheless, the research objective does not explicitly address a particular research gap. The authors should address an existing research gap to strengthen the research objective.

The article references scientific literature, such as studies on anaerobic digestion technologies, life cycle assessments, and sustainable waste management practices. They provide a good foundation for the research and support the study's methodology and findings. However, the scientific literature analysis in the article could be more comprehensive, including a more detailed discussion of previous studies on anaerobic digestion for municipal organic waste treatment, containing analysis of different approaches and outcomes, etc. The article could strengthen its theoretical framework by improving the scientific literature analysis in these ways.

 

Response: We added a paragraph on page 2, lines 67-85, to explicitly state the research gap and how our study fills it. Also, we have expanded the scientific literature analysis to include more detailed discussions of previous studies, as follows.

“Given the significant attention to AD technology, numerous studies have ad-dressed its technical aspects as well as the economic, environmental, and social di-mensions both quantitatively and qualitatively [11–13]. A recent review paper presents a comprehensive literature review of previous studies on AD for MOW treatment, fo-cusing on various approaches, including co-digestion, pre-treatment, recirculation, ad-ditive processes, and microaeration, evaluating their mechanisms and effectiveness in enhancing digestion performance [14]. Along with other review studies that advocate for improvements to make this technology more accessible and beneficial [15–18], there is a recognition that many analyses focus on AD technologies or individual pro-jects. However, fewer studies provide comprehensive regional analysis that includes related ventures involved in biomass initiatives. Comprehensive analysis from a re-gional perspective, particularly practical analysis based on site-specific empirical data, is still lacking. Biomass projects require the participation of multiple stakehold-ers—municipalities, private companies, and citizens—from waste separation to the use of liquid fertilizer on farmland. AD technology must be sustainably managed within complex social systems. In such systems, indirect benefits such as bartering or self-consumption, often unrecorded in conventional accounting, can significantly con-tribute to the regional socio-economic landscape. Therefore, the current study aims to fill this research gap by providing a comprehensive regional analysis based on empiri-cal data from Minamisanriku Town. This analysis includes economic, environmental, and social dimensions and evaluates the benefits and challenges of AD technology im-plementation from a regional perspective. By doing so, the study seeks to offer practi-cal insights that can inform policy and decision-making processes for sustainable waste management and regional revitalization.”

 

 

The methodology applied in the study involves a Life Cycle Assessment, stakeholder interviews, and scenario analysis. The methodology is appropriate for the research objective of assessing the economic and environmental impacts of anaerobic digestion in a specific location. I suggest the authors conduct a sensitivity analysis to test the robustness of the results under different assumptions to strengthen the validity of the findings.

 

Response: Our study incorporates a comprehensive methodology that includes Life Cycle Assessment, stakeholder interviews, and scenario analysis to evaluate the economic and environmental impacts of anaerobic digestion in Minamisanriku Town. We acknowledge the reviewer's suggestion regarding the importance of conducting a sensitivity analysis to test the robustness of our results under different assumptions. We plan to address this critical aspect in our subsequent research, where a detailed sensitivity analysis will be undertaken to enhance the validity and reliability of our findings. This future work will ensure a more robust understanding of the potential variations in outcomes based on different input scenarios and assumptions.

 

The main conclusions drawn from the study are significant and based on the research analysis. Nevertheless, the authors should include a discussion of the limitations or uncertainties in the findings to enhance the transparency and reliability of the conclusions. They should also offer recommendations for policymakers, waste management authorities, and other stakeholders to provide practical guidance.

 

Response: We included a discussion on the limitations and uncertainties of the findings, and provided recommendations for policymakers and other stakeholders on page 16-17, as follows.

“This study investigates the economic and environmental benefits of utilizing an-aerobic digestion (AD) for municipal organic waste (MOW) in Minamisanriku Town. The introduction of the BIO system demonstrates significant potential to transition the local business environment toward a more resource-efficient circular economy. Utiliz-ing MOW as liquid fertilizer, as well as for energy production and other high-value products, has been shown to greatly promote the sustainable use of local resources, reduce incineration and landfill waste, support organic agriculture, and contribute to the development of a self-sufficient and resilient local community.

To fully realize these benefits, it is essential to address challenges such as low waste collection rates and facility utilization. Maintaining and enhancing the capacity of the BIO system requires active roles from government, businesses, and citizens. Governments must commit to long-term investments and policy adjustments. Busi-nesses need to develop innovative business models and explore diverse funding sources. For instance, while the system currently relies heavily on municipal waste processing fees, there is potential to explore mechanisms for commercializing liquid fertilizer and seeking alternative funding sources like carbon credits. Such investments and business model innovations are crucial for fostering long-term community resili-ence and advancing transitions toward a decarbonized, circular, and nature-inclusive society.

Initial findings suggest that community engagement is critical for the success of the BIO system. While individual stakeholders benefit from the biomass initiative, broader contributions to the community's medium- to long-term development appear limited. There is a notable gap between the current state and the anticipated benefits, such as the maintenance of agricultural landscapes and the revitalization of communi-ty through integrated food and agriculture cycles. We hypothesize that closing this gap will require innovative collaboration among various stakeholders. Preliminary obser-vations indicate that providing feedback to residents and businesses about benefits and outcomes may foster ownership and cooperation. Additionally, partnerships with local food-related businesses could optimize system efficiency and promote sustaina-ble practices across the community. However, these are preliminary considerations based on initial investigations.

The study has several limitations that should be acknowledged. First, the research is based on a case study from Minamisanriku Town, which may limit the generaliza-bility of the findings to other regions with different environmental, economic, and so-cial contexts. Additionally, the analysis did not incorporate a sensitivity analysis to account for variations in key parameters, such as waste collection rates and fertiliz-er/rice market conditions, which could impact the overall outcomes. Future research should include a sensitivity analysis to explore how changes in these parameters might affect the economic and environmental benefits of the BIO system. Moreover, the ap-plicability of these strategies to other communities with diverse environmental and socio-economic conditions should be examined to enhance the robustness and applica-bility of the findings. Future studies will delve deeper into these aspects and explore strategies for achieving community-wide benefits and fostering truly integrated and sustainable regional ecosystems.”

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The scientific article matches the scope of the journal and adresses important new topics to engage circular economy. Anyway, there are some comments, which need to be incorporated:

- The link to SDGs is not made, SDG is a keyword of this paper and one sentence is written that the results of the paper are important to score the SDGs. It is not mentioned, which SDGs are adressed, how they are adressed and how they are affected in which way by the result - Although SDG is a keyword of this scientific article. Either the word SDG has to be eliminated as keyword or at least one paragraph in the results chapter needs to be added.

- I would really appreciate to have the scenarios listed in table form, so that it is clearly visible with one sight, what are the differences.

- Between headline 3 and headline 3.1 one paragraph needs to be added so that not two headlines are directly in series.

Author Response

The scientific article matches the scope of the journal and adresses important new topics to engage circular economy. Anyway, there are some comments, which need to be incorporated:

- The link to SDGs is not made, SDG is a keyword of this paper and one sentence is written that the results of the paper are important to score the SDGs. It is not mentioned, which SDGs are adressed, how they are adressed and how they are affected in which way by the result - Although SDG is a keyword of this scientific article. Either the word SDG has to be eliminated as keyword or at least one paragraph in the results chapter needs to be added.

Response: As suggested, we added a paragraph at the end of Section 4. Result to specify which SDGs are addressed and how, as follows

“The above results align with multiple United Nations Sustainable Development Goals (SDGs), demonstrating significant progress such as improved agricultural productivity (SDG 2), promotion of renewable energy usage and reduced reliance on fossil fuels (SDG 7), economic growth (SDG 8), advancements in education and gender equality (SDGs 4, 5, 9), sustainable consumption and production (SDG 12), mitigation of climate change (SDG 13), transformation of cities into sustainable environments (SDGs 11, 16, 17), and reduction of environmental pollution (SDGs 3, 6, 12, 14, 15).”

- I would really appreciate to have the scenarios listed in table form, so that it is clearly visible with one sight, what are the differences.

Response: We listed the scenarios in table form for clarity, as described above.

- Between headline 3 and headline 3.1 one paragraph needs to be added so that not two headlines are directly in series.

Response: We added the following sentences between headline 3 and headline 3.1.

“In this section, we outline the methodological framework employed in the study to assess the economic and environmental impacts of AD for MOW in Minamisanriku Town. The methodology encompasses a series of analytical steps, including boundary setting, scenario setting, information collection, and quantifying economic and environmental impact analysis, as well as the application of specific tools to evaluate the various dimensions of AD implementation.”

Author Response File: Author Response.pdf

Reviewer 5 Report

Comments and Suggestions for Authors

The paper “Assessing the Economic and Environmental Impacts of Anaerobic Digestion for Municipal Organic Waste: A Case Study of  Minamisanriku Town, Japan” presents an important and interesting subject for our days. Municipal waste is the most important source of waste, especially in modern urban society. An important fraction of  municipal waste is represented by organic waste. This fraction is used as feedstock for anaerobic digestion and biogas generation. The paper presents a case study about possibilities of exploiting organic waste to produce energy and bio fertilizer. The current situation with advantages and drawbacks is presented. Some possible scenarios are investigated.

 

Some corrections are necessary.

Line 25 – correct “Lime” to “LIME”

Line 26 – give the complete significance for “SDGs”

I suggest moving Figure 1 after the first paragraph of chapter 2.

Line 158 - give the complete significance for “ICT”

Figure 2a – there is no data for the year 2010; There is no explanation in the text body for the lack of data.

Figure 3 – increase the text font- legend of the figure is quite difficult to read.

Lines 235-239 – The facility sells about 21,582 kWh and acquire about 28,215 kWh. Why is that? As I understand from table 2 the selling cost is 7.55 JPY/kWh and the acquisition cost is 29 JPY/kWh.

The scenario presentation is not clear. I expect to see explanations for the  eight’s scenarios. You give for example the scenario S1-1,  S2-1; S1 means 56% operations, S2 means 100% operation. What represents 2L, 2C Which scenario is the real one?

Table 2 – the text is very difficult to read because of the dimension of letters.

Figure 4 – I suggest increasing the figure body or changing the colors for each sector expenses/ income; some data  could not be seen clearly.

Figure 5 – I suggest changing the increment value for the scale, use 25 instead of 50.

Line 560 – it is “traction” or it should be “attraction” ?

Author Response

Line 25 – correct “Lime” to “LIME”

Response: Revised. Thank you so much.

 

Line 26 – give the complete significance for “SDGs”

Response: Revised to “Sustainable Development Goals (SDGs)”.

 

I suggest moving Figure 1 after the first paragraph of chapter 2.

Response: Moved Figure 1 after the first paragraph of chapter 2.

 

Line 158 - give the complete significance for “ICT”

Response: Revised to “Information and Communication Technology (ICT)”.

 

Figure 2a – there is no data for the year 2010; There is no explanation in the text body for the lack of data.

Response: It is due to the Great East Japan Earthquake on 11 March 2011, as explained in the Section 2.

 

Figure 3 – increase the text font- legend of the figure is quite difficult to read.

Response: Fully revised.

 

Lines 235-239 – The facility sells about 21,582 kWh and acquire about 28,215 kWh. Why is that? As I understand from table 2 the selling cost is 7.55 JPY/kWh and the acquisition cost is 29 JPY/kWh.

Response: It has been revised as “A significant portion of the electricity (45,013 kWh per year) is self-consumed by the facility, with 21,582 kWh per year sold externally. The facility also consumes 28,215 kWh of purchased electricity per year.”

 

The scenario presentation is not clear. I expect to see explanations for the eight’s scenarios. You give for example the scenario S1-1,  S2-1; S1 means 56% operations, S2 means 100% operation. What represents 2L, 2C Which scenario is the real one?

Response: Fully revised as response to Reviewer 1 above.

 

Table 2 – the text is very difficult to read because of the dimension of letters.

Response: Fully revised as response to Reviewer 1 above.

 

Figure 4 – I suggest increasing the figure body or changing the colors for each sector expenses/ income; some data could not be seen clearly.

Response: Fully revised.

 

Figure 5 – I suggest changing the increment value for the scale, use 25 instead of 50.

Response: Fully revised.

 

Line 560 – it is “traction” or it should be “attraction” ?

Response: Revised.

 

Thank you again for your positive and constructive comments and suggestions on our manuscript. We have tried our best to improve the manuscript and made some changes in manuscript. We appreciate for your warm work earnestly, and really hope that the correction will meet with approval.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The revisions to the manuscript are very well done. However, a few details still need to be addressed before it can be accepted. Here are three specific comments:

1. Figure 1: The legend is too simplistic and needs more detail. Please consider adding specific descriptions for each area. Additionally, the figure is blurry and should be provided in a clearer version. A suggested title for the figure is "Remote Sensing Land Use Classification in Minamisanriku Town, Japan." I recommend reviewing similar academic papers for better examples of legend format and details.

2. Table 1: It would improve readability to convert Table 1 into a three-line table. In the "year" column, remove the extra period after "2013" (currently "2013."). If months follow the year, use English month names instead of numbers. In academic papers, months typically precede the year, formatted as "Month Year" (e.g., "January 2013").

3. Figure 4: This figure does not appear to be a vector graphic and lacks clarity. Please ensure that Figure 4 is provided in a vector format (e.g., SVG) to enhance its clarity.

Author Response

Dear Editor and Reviewers,

We appreciate the time and effort you have invested in reviewing our manuscript and providing insightful comments. We have carefully considered each of your suggestions and have made the necessary revisions to improve the clarity, depth, and overall quality of the paper. Below, we detail the changes made in response to each comment.

Reviewer 1

Figure 1: The legend is too simplistic and needs more detail. Please consider adding specific descriptions for each area. Additionally, the figure is blurry and should be provided in a clearer version. A suggested title for the figure is "Remote Sensing Land Use Classification in Minamisanriku Town, Japan." I recommend reviewing similar academic papers for better examples of legend format and details.

Response: Thank you for your kind suggestions. We revised Figure 1 to enhance the clarity and detail of the legend, providing specific descriptions for each area following Japan’s land use classification.

Paddy Fields: Refers to areas of rice paddies; Other Agricultural Land: Includes farmland such as fields and orchards; Forest: Areas densely populated with trees; Wasteland: Land not used for agriculture or urban purposes; Building Area: Land with buildings such as residential, commercial, and industrial areas; Major Transportation Land: Land with major transportation infrastructure such as highways and railways; Other Land Use: Other land uses that do not fall into specific categories; River and Lake Area: Areas of water bodies such as rivers, lakes, and ponds; Coastal Area: Land along the coastline; Marine Area: Sea areas.

Also, we added a detailed description for Figure 1 on page 3, lines 117-129, as follows.

“Minamisanriku Town, the focus of this study, is located on the northeastern coast of Miyagi Prefecture in the Tohoku region of Japan (Figure 1, left), with a population of 11,496 in 2024. The map on the right of Figure 1 provides a detailed land use classification of Minamisanriku in 2016. Different colors are used to represent various land use types. The map illustrates the preponderance of forested areas (depicted in green) and the distribution of land designated for agricultural and urban use. The proximity of the town to the coastline and the presence of various land types provide insight into the socio-economic and environmental context relevant to the study of anaerobic digestion for municipal organic waste. Forested areas (green) account for nearly 80% of the land, agricultural land (brown) covers approximately 6% (around 1,000 hectares), and urban areas (red and orange) represent about 5%. Including other areas such as submerged regions and wasteland (yellow), there is a potential to utilize liquid fertilizer (digestate from anaerobic digestion) on over 2,000 hectares of land.”

However, the primary purpose of Figure 1 is to show the location of the study area rather than providing a detailed Remote Sensing Land Use Classification. Therefore, we would like to keep the current title for the figure 1. Additionally, it serves to give a rough confirmation of the land potential for liquid fertilizer cultivation. The figure was created using free 100m x 100m resolution ArcGIS data available for download. Due to the limitations of this free data source, producing a higher-resolution image is not feasible. Therefore, while the figure may appear simplistic, it effectively meets its intended objectives within the constraints of the available resources.

• Table 1: It would improve readability to convert Table 1 into a three-line table. In the "year" column, remove the extra period after "2013" (currently "2013."). If months follow the year, use English month names instead of numbers. In academic papers, months typically precede the year, formatted as "Month Year" (e.g., "January 2013").

Response: We converted Table 1 into a three-line table to enhance readability. The extra period after "2013" was removed, and English month names was used instead of numbers, formatted as "Month Year" (e.g., "January 2013").

• Figure 4: This figure does not appear to be a vector graphic and lacks clarity. Please ensure that Figure 4 is provided in a vector format (e.g., SVG) to enhance its clarity.

Response: We provided Figure 4-6 in a vector format (e.g., SVG) to enhance its clarity and ensure that it meets publication standards. Also, we uploaded all original figures by ZIP.

Thank you again for your positive and constructive comments and suggestions on our manuscript. We have tried our best to improve the manuscript and made some changes in manuscript. We appreciate for your warm work earnestly, and really hope that the correction will meet with approval.

Author Response File: Author Response.pdf