Evaluation of Urban Sustainability Based on Development Structures and Economic Aggregates: A Case Study of Jiaxing, China

Round 1

Reviewer 1 Report

1. It is of practical significance to measure urban sustainability from the perspective of development structure and economic aggregate.  In the process of accounting for green GDP and the value in the evaluation system in previous studies, it was very difficult to obtain the original data. Lines 132-135 of the manuscript explained the source of the original data.  Could you describe in more detail how the data were used during the study and provide a detailed list of the original data? 

2.  Lines 82-85 of the manuscript illustrate that energy theory considers pollutants emitted by cities as a natural process, and the damage of pollutants to urban economy, society and environment can be quantified by internalizing pollutants into urban metabolic processes.  In section 3.2.1, it is concluded through calculation that the local ecological service supply capacity is not enough to support the environmental absorption and dilution process of water pollution, which is actually a conclusion based on statistical data in an ideal situation.  However, in the actual urban water pollutant treatment system, whether the sewage treatment capacity provided by the sewage treatment facilities has been considered?  It is a matter of whether the calculation of ecological service supply and additional resource revenue is accurate and reliable. 

3. Part 3.3 and 3.4 of this paper respectively discuss the sustainability evaluation of urban development structure and the sustainability evaluation of urban economic aggregate in detail, and obtain the data with great guiding and practical significance.  In section 3.5, the sustainability evaluation of development structure and economic aggregate is combined, and the coupling of the two systems needs more detailed analysis and discussion. 

4.  The quantification of development structure is mainly referred to as economic structure in this paper, so please explain whether economic structure can refer to development structure, and describe in detail the definitions and differences between development structure and economic structure in this paper. 

5. Urban sustainability refers to the sustainability of economy, society, ecological environment and other aspects. The author only selects the evaluation indicators of urban sustainable development based on EMERGY, so it is necessary to consider whether the selected indicators are comprehensive, reasonable and can reflect the sustainability of cities. 

6. In the evaluation result, only one value is used to reflect the comprehensive sustainable situation of Jiaxing City, but this result may not reflect the real urban sustainable level.  For example, the results of a small number of regions are considerable enough to make up for the deficiencies of most regions, so the comprehensive evaluation results at this time cannot show whether Jiaxing has the ability of urban sustainable development. 

7. Natural environment includes land resources, climate resources, water resources, biological resources, mineral resources and so on.  The author only selected less than ten indicators of air pollution and water pollution to calculate the ecological and environmental costs and human resource losses, have they considered comprehensively? 

Author Response

1. It is of practical significance to measure urban sustainability from the perspective of development structure and economic aggregate. In the process of accounting for green GDP and the value in the evaluation system in previous studies, it was very difficult to obtain the original data. Lines 132-135 of the manuscript explained the source of the original data. Could you describe in more detail how the data were used during the study and provide a detailed list of the original data?

Authors’ response: Thank you for your suggestion. The original data of the urban ecosystem from 2012 to 2018 in Jiaxing has been added in Table S1, please see in Supplementary Materials.

The method for calculating emergy based on the original data has been described in 2.2 Research method, including emergy accounting, quantification of eco-environmental costs and sustainability evaluation of urban ecosystem.

 

2. Lines 82-85 of the manuscript illustrate that energy theory considers pollutants emitted by cities as a natural process, and the damage of pollutants to urban economy, society and environment can be quantified by internalizing pollutants into urban metabolic processes. In section 3.2.1, it is concluded through calculation that the local ecological service supply capacity is not enough to support the environmental absorption and dilution process of water pollution, which is actually a conclusion based on statistical data in an ideal situation. However, in the actual urban water pollutant treatment system, whether the sewage treatment capacity provided by the sewage treatment facilities has been considered? It is a matter of whether the calculation of ecological service supply and additional resource revenue is accurate and reliable.

Authors’ response: Thank you for your suggestion. Actually, the pollutant emissions used in this study were derived from the data in the Statistical Yearbook. The annual emissions of major pollutants are recorded in the Statistical Yearbook released by the government every year. These data are based on the monitoring of the discharge of air and water pollutants from major industrial enterprises. These data have taken into account the removal effects of end-treatment facilities (including sewage treatment plants). Therefore, this study does not consider the treatment capacity of the sewage treatment plants. Moreover, the data released by the government is relatively accurate and can reflect the emission of pollutants in the city.

This study evaluates the urban sustainability by using the accepted emergy theory, which has been widely used all over the world. For example:

[1]Pan H, Zhang X, Wu J, et al. Sustainability evaluation of a steel production system in China based on emergy[J]. Journal of cleaner production, 2016, 112: 1498-1509.

[2]Londoño N A C, Velásquez H I, McIntyre N. Comparing the environmental sustainability of two gold production methods using integrated Emergy and Life Cycle Assessment[J]. Ecological Indicators, 2019, 107: 105600.

[3]Ulgiati S, Brown M T. Quantifying the environmental support for dilution and abatement of process emissions: the case of electricity production[J]. Journal of Cleaner Production, 2002, 10(4): 335-348.

Therefore, we believe that our conclusions are accurate and reliable.

 

3. Part 3.3 and 3.4 of this paper respectively discuss the sustainability evaluation of urban development structure and the sustainability evaluation of urban economic aggregate in detail, and obtain the data with great guiding and practical significance. In section 3.5, the sustainability evaluation of development structure and economic aggregate is combined, and the coupling of the two systems needs more detailed analysis and discussion.

Authors’ response: Thank you for your suggestion. We have enhanced the discussion in Section 3.5. See lines 460-466, page 14.

 

4. The quantification of development structure is mainly referred to as economic structure in this paper, so please explain whether economic structure can refer to development structure, and describe in detail the definitions and differences between development structure and economic structure in this paper.

Authors’ response: Thank you for your suggestion. The evaluation of urban development structure in this study is based on the comprehensive evaluation of natural, social and economic subsystems, rather than economic subsystem. Therefore, the economic structure and the development structure are different, and the economic structure is only a part of the development structure. The emergy evaluation indicators of the sustainability evaluation of urban development structures are listed in Table S7, and the results are shown in Section 3.3.

 

5. Urban sustainability refers to the sustainability of economy, society, ecological environment and other aspects. The author only selects the evaluation indicators of urban sustainable development based on EMERGY, so it is necessary to consider whether the selected indicators are comprehensive, reasonable and can reflect the sustainability of cities.

Authors’ response: Thank you for your suggestion. Emergy theory is a common method to evaluate urban sustainability. Based on emergy theory, this study selects green GDP and emergy indicators of economic subsystem, social subsystem and environmental subsystem to evaluate urban sustainable development from two aspects of development structure and economic aggregate, which can comprehensively and reasonably reflect urban sustainability. Compared with other studies, this study comprehensively evaluates urban sustainability from two aspects: development structure and economic aggregate. Therefore, we believe that the evaluation results of this study are reliable and can reflect the sustainable development of a city.

 

6. In the evaluation result, only one value is used to reflect the comprehensive sustainable situation of Jiaxing City, but this result may not reflect the real urban sustainable level. For example, the results of a small number of regions are considerable enough to make up for the deficiencies of most regions, so the comprehensive evaluation results at this time cannot show whether Jiaxing has the ability of urban sustainable development.

Authors’ response: Thank you for your suggestion. Emergy is a theoretical system that contains a series of indicators to evaluate the sustainability of a city (as mentioned in point 5). Therefore, we believe that the evaluation results are comprehensive and credible. The data used in this study are the data of Jiaxing city, and the differences between regions of Jiaxing city are not distinguished, so the conclusion reflects the urban sustainability of Jiaxing city. As for the differences between different regions, this study does not cover.

 

7. Natural environment includes land resources, climate resources, water resources, biological resources, mineral resources and so on. The author only selected less than ten indicators of air pollution and water pollution to calculate the ecological and environmental costs and human resource losses, have they considered comprehensively?

Authors’ response: Thank you for your suggestion. In this study, air pollution and water pollution indicators with high emissions and significant impacts on ecological and environmental costs and human resource losses based on DALY and PDF of various pollutants in Eco-Indicator 99 are comprehensively considered, and the corresponding energy values are calculated as the impacts of natural subsystem on urban sustainable development. Some of the ecological indicators you mentioned, such as land resources, climate resources, water resources, biological resources, mineral resources, are not included in Eco-Indicator 99. The evaluation indicator system of the ecological and environmental costs and human resource losses only include environmental pollutants.

Author Response File: Author Response.docx

Reviewer 2 Report

Summary Comments:

1.      Significance: This manuscript constructs an assessment method of urban sustainability from development structures and economic aggregates based on emergy. A comprehensive assessment of sustainable urban development helps to understand the resistances that constrain it and the dynamics that drive it in the context of internal factors, so that provide methodological guidance for urban sustainable evaluation.

2.      Novelty: The topic is interesting and valuable in urban sustainable development, enriching the contents and assessment methods of urban sustainable development. It compensates for the deficiencies of integrated consideration between the development structures and the economic aggregate in existing studies.   

3.      Method: Normal

4.      Experiment: Normal

5.      English writing: English should be improved

However, there are still some technical issues that need to be clarified before accepting it for publication, as follows:

Specific Comments:

1.      The manuscript should begin by explaining the background and significance of the study of urban sustainable development, on the basis of which to analysis the necessity from two aspects of development structures and economic aggregates of urban sustainable development analysis is more reasonable.

2.      Please elaborate on the scientific aspects of the article where appropriate, add to the theoretical presentation of the article, add more solid theoretical basis to justify the significance of evaluation of urban sustainability based on both development structures and economic aggregates.

3.      The manuscript evaluates the city of Jiaxing for urban sustainability from 2005-2018, the results of which are not very instructive for current actual urban construction and suggest adding more updated data for evaluation.

4.      The line 183 refers to use the ecological service emergy of diluting air pollutants and water pollutants to calculate the emergy of ecological services. Is it reasonable? Please provide a detailed description.

5.      The line 423 refers to five indicators with high correlation coefficients to illustrate the relationship between green GDP and related resources, please give a detailed and reasonable explanation of the treatment of this data.

 

Comments for author File: Comments.pdf

Author Response

Summary Comments:

1. Significance: This manuscript constructs an assessment method of urban sustainability from development structures and economic aggregates based on emergy. A comprehensive assessment of sustainable urban development helps to understand the resistances that constrain it and the dynamics that drive it in the context of internal factors, so that provide methodological guidance for urban sustainable evaluation.

Authors’ response: Thank you for your comments.

 

2. Novelty: The topic is interesting and valuable in urban sustainable development, enriching the contents and assessment methods of urban sustainable development. It compensates for the deficiencies of integrated consideration between the development structures and the economic aggregate in existing studies.

Authors’ response: Thank you for your comments.

 

3. Method: Normal

Authors’ response: Thank you for your comments.

 

4. Experiment: Normal

Authors’ response: Thank you for your comments.

 

5. English writing: English should be improved

Authors’ response: Thank you for your suggestion. We have asked native English speaker to polish the language of the manuscript. If the language needs to be improved later, we will make further modifications.

 

However, there are still some technical issues that need to be clarified before accepting it for publication, as follows:

Specific Comments:

1. The manuscript should begin by explaining the background and significance of the study of urban sustainable development, on the basis of which to analysis the necessity from two aspects of development structures and economic aggregates of urban sustainable development analysis is more reasonable.

Authors’ response: Thank you for your suggestion. The introduction of the manuscript is written along these lines. First of all, it raises the question that with the rapid development of economy, the ecological environment of the city is facing a series of problems, which seriously restrict the sustainable development of the city. Then it is introduced that the current evaluation of urban sustainability is mainly based on the development structure, while ignoring the impact of economic aggregate on urban sustainability, resulting in inaccurate evaluation results. Finally, it is suggested that urban sustainability should be evaluated comprehensively by integrating development structure and economic aggregate. We have strengthened the expression of introduction, see lines 37-54, page 1-2.

 

2. Please elaborate on the scientific aspects of the article where appropriate, add to the theoretical presentation of the article, add more solid theoretical basis to justify the significance of evaluation of urban sustainability based on both development structures and economic aggregates.

Authors’ response: Thank you for your suggestion. Development structure and economic aggregate are two main aspects of urban sustainable development. Previous studies have evaluated urban sustainability from a single aspect of development structure and economic aggregate. This study is the first to evaluate the sustainability of a city by integrating its development structure and economic aggregate. Therefore, the relevant theoretical basis is less. We expatiate on the theoretical basis of development structure and economic aggregate respectively, and explore their combined evaluation. Detailed information can be found in the introduction.

 

3. The manuscript evaluates the city of Jiaxing for urban sustainability from 2005-2018, the results of which are not very instructive for current actual urban construction and suggest adding more updated data for evaluation.

Authors’ response: Thank you for your suggestion. Actually, we started working on this manuscript in 2020, and it went through a lot of revisions to get to the current version. Therefore, we only collected the data from statistical yearbooks up to 2018, and the data from 2019 onwards were not updated in the manuscript. Nevertheless, between 2005 and 2018, China's development has changed dramatically, from the pursuit of economic growth to the sustainable development of nature, economy and society. Especially after the 18th National Congress of the Communist Party of China in 2012, the idea of ecological civilization made the government strengthen the restoration of the ecological environment and further strengthen the sustainability of the city. Therefore, the analysis of urban sustainability during this period (covering the 11th, 12th and 13th Five-Year) can provide support for the sustainable development of the city in the future.

 

4. The line 183 refers to use the ecological service emergy of diluting air pollutants and water pollutants to calculate the emergy of ecological services? Please provide a detailed description.

Authors’ response: Thank you for your suggestion. This method is a simplified simulation method. Nature has the power of self-purification. When pollutants are released into the surrounding environment, the atmosphere and water in nature provide the services of dilution, desalination or decomposition, resulting in the concentration of pollutants reaching an acceptable range for the ecosystem. Therefore, it is reasonable to use the emergy of diluting air pollutants and water pollutants to calculate the emergy of ecological services. This is the standard definition of ecological services in emergy theory.

 

5. The line 423 refers to five indicators with high correlation coefficients to illustrate the relationship between green GDP and related resources, please give a detailed and reasonable explanation of the treatment of this data.

Authors’ response: Thank you for your suggestion. In this study, the indicators of Nonrenewable resources and products (N) and Waste (W), which affect the change of green GDP, were selected, and the correlation coefficients between each indicator and green GDP were calculated. Finally, five indicators with larger absolute value of correlation coefficient were selected for sensitivity analysis. For detailed indicator description, see Table S1,S2.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

1.      Lines 52-59 of the manuscript, the number of references cited to illustrate the shortcomings of using urban development structures to evaluate urban sustainability assessments is too small. The same problem arises when lines 66-72 illustrate that economic aggregates is difficult to assess objectively for urban sustainability. More relevant literature needs to be added to illustrate the problems with single evaluations, while it could support the authors' view that combining the two is a better assessment perspective. In addition, it is necessary to add a section before the empirical study to show how the combination of development structures and economic aggregates together enriches the urban sustainability evaluation study.

Author Response

Lines 52-59 of the manuscript, the number of references cited to illustrate the shortcomings of using urban development structures to evaluate urban sustainability assessments is too small. The same problem arises when lines 66-72 illustrate that economic aggregates is difficult to assess objectively for urban sustainability. More relevant literature needs to be added to illustrate the problems with single evaluations, while it could support the authors' view that combining the two is a better assessment perspective. In addition, it is necessary to add a section before the empirical study to show how the combination of development structures and economic aggregates together enriches the urban sustainability evaluation study.

Authors’ response: Thank you for your suggestion. The references have been added in the manuscript, please see lines 73 and 84, page 2. In addition, we have added the importance of the combined evaluation of economic aggregates and development structures in the introduction, please see lines 82-95, page 2.

Besides, we have embellished the language of the manuscript, please see the revised manuscript for details.

Author Response File: Author Response.docx