Ecological Health Assessment with the Combination Weight Method for the River Reach after the Retirement and Renovation of Small Hydropower Stations
Round 1
Reviewer 1 Report
The research presented is relevant and demonstrates a comprehensive and reasonable method for classifying river stretches before and after reservoir demolition. In addition, it can represent a direction to evaluate rivers that have undergone major modifications or impacts and follow their evolution.Author Response
Thank you for your comments and recognition, we are glad to hear that.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This study was focused on the evaluation of the ecological restoration of the river reach where a small hydropower station was retired and renovated. I think this study is interesting and will be a valuable contribution to the field. But, there existed problems, such as evaluation models, ambiguous introduction, general conclusion. So, the article would benefit from major revisions before publication.
1. The abstract is too general and the significance of the study is lacking.
2. There are too many errors in the introduction, the references are missing, and the references are not marked in the paper. It is suggested to check the marking standards of the references uniformly and increase the status quo of relevant researches at home and abroad.
3. The preface discusses a variety of evaluation models. Why does the author choose fuzzy comprehensive evaluation and why not choose other models? What's new about your research compared to previous research?
4. Why are these indicators selected in the second part of the method, and whether these indicators are universal?
5. The discussion of evaluation method and evaluation model is missing in the fifth part, so it is suggested to add
6. The conclusion of the sixth part is too general, so it is suggested to rewrite it.
Author Response
This study was focused on the evaluation of the ecological restoration of the river reach where a small hydropower station was retired and renovated. I think this study is interesting and will be a valuable contribution to the field. But, there existed problems, such as evaluation models, ambiguous introduction, general conclusion. So, the article would benefit from major revisions before publication.
Response: Thank you for your comments. We have made corrections according to your comments.
- The abstract is too general and the significance of the study is lacking.
Response: Those comments are all valuable and very helpful for revising and improving the abstract. The added part is as follows.
The proposed model can be used for the rational development of water resources, the protection of rural water environments in mountainous areas, and the coordination of hydropower station development and river ecological health maintenance.
The abstract was re-organized according to the suggestions. (lines 17-29)
- There are too many errors in the introduction, the references are missing, and the references are not marked in the paper. It is suggested to check the marking standards of the references uniformly and increase the status quo of relevant researches at home and abroad.
Response: We are very sorry for our incorrect references.we have rechecked the marking standards of the references uniformly and increased the status quo of relevant researches at home and abroad.
- The preface discusses a variety of evaluation models. Why does the author choose fuzzy comprehensive evaluation and why not choose other models? What's new about your research compared to previous research?
Response: Thank you for your suggestion We have added the reason for choosing fuzzy comprehensive evaluation and the comparison with previous research. (lines 86-108)
The added part is as follows.
River ecological health assessment involves numerous, complex phenomena and inter-actions among various factors, which include many fuzzy phenomena and fuzzy concepts. It is necessary to incorporate the fuzziness of river ecological health when evaluating the effects of the retirement and renovation of small hydropower stations. In this study, we use a fuzzy comprehensive assessment to resolve uncertainty problems in the assessment. However, the weight distribution of this method is subjective.
Special thanks to you for your good comments.
- Why are these indicators selected in the second part of the method, and whether these indicators are universal?
Response: We are sorry that we didn’t make ourselves clear. we considered environmental changes in upstream and downstream of of the dam after the retirement and renovation of a small hydropower stations and according to the previous research to target indicators over a scientific, comprehensive evaluation index system. These indicators are universal when applied to the assessment of river ecological health under the influence of small hydropower stations
We have supplemented the reasons for selecting these indicators and their applicability in the second part of the method. (lines 125-133)
- The discussion of evaluation method and evaluation model is missing in the fifth part, so it is suggested to add
Response: We are very sorry for missing the discussion of evaluation method and evaluation model. These contents have been added in the discussion. (lines 384-391).
The added part is as follows.
Taking Shimen Hydropower Station as an example, the calculated membership degree of the very healthy state was 36% in 2018 and increased to 38% in 2019, which is consistent with the actual situation. The proposed model appears to accurately reflect changes in the river ecological restoration status after the retirement of Shimen. It un-ambiguously and accurately reveals the river’s ecological health after the small hydro-power station is retired. The index weights calculated by the proposed combination method fall between the subjective weight and objective weight, indicating that the model fully incorporates both subjective and objective information.
Special thanks to you for your good comments.
- The conclusion of the sixth part is too general, so it is suggested to rewrite it.
Response: Thank you for your comment. We have re-written the conclusion according to the Reviewer’s suggestion. (lines 417-445)
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
The authors have improved the manuscript including the grammar, method, result and discussion. So, the manuscript can be accepted by the journal.
