Risk Assessment of Water Inrush of a Coal Seam Floor Based on the Combined Empowerment Method

Round 1

Reviewer 1 Report

The manuscript attempts to address a very interesting problem of Threat Zoning and Classification of Mine Water Inrush using combination of Fuzzy AHP and Entropy Weight Method. I enjoyed reading the manuscript, as it matches with my on-going research. After a careful evaluation of the manuscript, I put forward some suggestions for authors so as to improve the quality of the manuscript before publication. 1. Abstract (Line 19-20): How do six factors controlled the floor water inrush? 2. Abstract (Line 21-22): Why do you call the combination of Fuzzy AHP and Entropy weight method as an improved method? 3. Introduction: Authors have ignored scientific discussion of the literature on Threat Zoning and Water Inrush Classification. Authors are limited to mentioning national and international publication using several methods. There is no scientific discussion. 4. There is lack of describing problem statement and research gap about Threat Zoning and Water Inrush Classification. 5. To describe the the verstality of the fuzzy AHP and Entropy Weight Method, there must be a little description of their application and integration with several others methods. For example, the strength of the entropy weight method and fuzzy AHP to combine with other methods. Plase see (1) http://dx.doi.org/10.1007/s42461-021-00444-5; (2) https://doi.org/10.1016/j.resourpol.2021.102007 and (3) https://doi.org/10.1007/s12517-020-06090-3 6. The term “Mining Failure” needs to be explained. What do authors want to say. It is difficult for the readers to understand what is it. 7. As shown in Fig. 9, authors have developed an evaluation index of the “Water Inrush Hazard Evaluation”. There must be a little literature on how to develop an evaluation index. Please refer to previous studies on the mining based on evaluation index. Refer to (1) https://doi.org/10.1007/s10668-022-02206-9 in order to see how the index is developed and how the AHP is improved with integration with Grey Theory; (2) https://doi.org/10.1007/s42461-020-00236-3 for evaluation index research in mining; (3) https://doi.org/10.1016/j.eswa.2021.116062 for how the evaluation index is integrated in decision support system and how Fuzzy AHP is used with other methods, and (4) https://doi.org/10.1186/s42834-020-00054-8 how the evaluation index is constructed according to well established models. 8. Section 5 (Assessment of Water Inrush Risk of Coal Floor): Authors have presented the results of the study very well. However, they have ignored to provide scientific discussion about the causative factors. How each of the factors evaluation contribute to the water inrush. In addition, there is no connection with the previously done research. Please improve it.

Author Response

Response to Reviewer 1 Comments

 

Point 1: Abstract (Line 19-20): How do six factors controlled the floor water inrush? 

 

Response 1: In the abstract, the description of water inrush factors has been improved, specifically described as water pressure and water richness provide water source and power for floor water inrush, the thickness of effective aquifer and the ratio of brittle rock can restrain floor water inrush, fault structures provide water inrush channels, mining damage is artificial interference and increases the probability of water inrush. Therefore, six factors of water pressure of the Ordovician limestone aquifer, water abundance of the Ordovician limestone aquifer, equivalent thickness of effective aquifuge, brittle rock ratio, fracture structure and mining destruction are selected as the influencing factors of water penetration of the bottom plate, and the drawing software is used to establish the mining area special map of related factors.(Line 18-26)

 

Point 2:  Abstract (Line 21-22): Why do you call the combination of Fuzzy AHP and Entropy weight method as an improved method?

 

Response 2: This paper introduces the combination of two weighting methods, namely the improved fuzzy analytic hierarchy process and entropy weight method. Among them, the improved fuzzy analytic hierarchy process is simpler than the analytic hierarchy process algorithm, without the consistency test of the judgment matrix, and the weight is more reasonable.

 

Point 3: Introduction: Authors have ignored scientific discussion of the literature on Threat Zoning and Water Inrush Classification. Authors are limited to mentioning national and international publication using several methods. There is no scientific discussion.

There is lack of describing problem statement and research gap about Threat Zoning and Water Inrush Classification.

 

Response 3: This paper has added a detailed description of the classification of water inrush risk and analyzed the current research status. The paper also discusses how to classify the risk of water inrush.(Line 81-86)

 

Point 4: To describe the the verstality of the fuzzy AHP and Entropy Weight Method, there must be a little description of their application and integration with several others methods. For example, the strength of the entropy weight method and fuzzy AHP to combine with other methods. Plase see(1)http://dx.doi.org/10.1007/s42461-021-00444-5;(2)https://doi.org/10.1016/j.resourpol.2021.102007 and (3) https://doi.org/10.1007/s12517-020-06090-3.

 

Response 4: Based on the literature provided by reviewers, the paper makes a comparative analysis of ahp and other methods, and discusses the differences between them. Added this aspect of the problem of modification and summary.(Line 92-111)

 

Point 5:  The term “Mining Failure” needs to be explained. What do authors want to say. It is difficult for the readers to understand what is it.

 

Response 5: The article has changed “Mining Failure” to “Mining damage”. Mining damage refers to the stope space after coal seam mining, which causes the original stress change of surrounding rock. When the stress borne by surrounding rock exceeds its ultimate strength, displacement, cracking, fracture and breakage will occur. When overburden deformation or displacement changes the water conductivity and water isolation performance of rock strata, it belongs to mining damage effect.According to the degree and form of damage, mining damage affects caving and cracking. The damage of coal seam floor can be expressed by the depth of floor damage zone.(Line 228-242)

 

Point 6: As shown in Fig. 9, authors have developed an evaluation index of the “Water Inrush Hazard Evaluation”. There must be a little literature on how to develop an evaluation index. Please refer to previous studies on the mining based on evaluation index. Refer to (1) https://doi.org/10.1007/s10668-022-02206-9 in order to see how the index is developed and how the AHP is improved with integration with Grey Theory; (2) https://doi.org/10.1007/s42461-020-00236-3 for evaluation index research in mining; (3) https://doi.org/10.1016/j.eswa.2021.116062 for how the evaluation index is integrated in decision support system and how Fuzzy AHP is used with other methods, and (4) https://doi.org/10.1186/s42834-020-00054-8 how the evaluation index is constructed according to well established models.

 

Response 6: Based on the references provided by the reviewers, I have added the literature on developing an evaluation index.(Line 255-256)

 

Point 7: Section 5 (Assessment of Water Inrush Risk of Coal Floor): Authors have presented the results of the study very well. However, they have ignored to provide scientific discussion about the causative factors. How each of the factors evaluation contribute to the water inrush. In addition, there is no connection with the previously done research. Please improve it.

 

Response 7: Results and discussion are added to describe the results of the evaluation model and the impact of water inrush factors on the results. At the same time, the discussion part increases the inspection strength of the evaluation model, through the actual mining situation of coal seam to test the accuracy of the evaluation results, and further illustrate the accuracy of the evaluation model. At the same time, relevant suggestions are put forward for the mine staff to provide guidance for the future work.(Line 267-384)

 

Please refer to the attachment for the specific modification of the article.

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper is interesting and can be published.

Author Response

Please refer to the attachment for the specific modification of the article.

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Authors,

I have read your article titled „Study on Threat Zoning and Classification of Floor Water Inrush by Multi-Source Information Coupling Based on Improved Fuzzy Analytic Hierarchy Process-Entropy Weight Method” submitted for consideration for publication in Water, MDPI.

 

The paper deals with the issue of groundwater inrush into the underground mining system by applying an innovative approach based on Fuzzy AHP.

Overall, the article is properly designed and written using good English. Research results are supported by analyses conducted. Also, the quality of the figures is appropriate to the standards of MDPI journals. Given the foregoing, I recommend publishing the article in its current form.

 

Kind regards,

Reviewer

Author Response

Thank you very much for your comments！

Please refer to the attachment for the specific modification of the article.

Author Response File: Author Response.pdf

Reviewer 4 Report

The manuscript investigates the factors that affect the sudden and overwhelming flow of water into mining operations through a combination of two basic techniques for determining each factor's weight and spatial distribution.

The study considers mainly cases of coal seam exploitation in lower depths, where the hydrogeological conditions play a crucial role in the exploration and exploitation mining procedures. Studying at a hazard level, the possible threats of floor water inrush during mining operations are essential for comprehensive sustainable mine planning and design. Furthermore, such a study could give the appropriate circumstances for a water inrush risk assessment in mining areas. The authors have selected two well-known techniques for the analysis, and the factors selected are also the most representative.

However, there are some significant concerns with the manuscript. Although the manuscript's content has high research interest, the research conducted is not well demonstrated. Firstly, the manuscript lacks a critical literature review. Instead, the literature review is a simple reference citation. In addition, the methodological quality of the manuscript is relatively poor and needs to be improved. Specifically, the methods that were used for the spatial analysis of the factors were not described and explained appropriately.  

Additional comments and recommendations for the improvement of the manuscript:

1. The title of the manuscript should be improved; it should be shorter, more informative, and attractive. For example, the title's words "Coupling Based" are not comprehensively composed. In addition, keywords such as "coal mine" could be added to the title to represent the manuscript's context better.
2. The abstract needs to be improved to be more informative regarding the case analyzed and the main extracted results.
3. Each one of the keywords should be shorter.

1. The literature review needs to be more critical.
2. The English language needs to be improved throughout the manuscript.
3. A separate paragraph that will describe the innovative contribution of the manuscript and the research gap should be included in the "Introduction" section. Subsections 1.1 and 1.2 could be moved to the "Materials and Methods" section.
4. The sections of the manuscript should follow the journal's template. Furthermore, subsection "2.1 Aquifer" is not described, and the title is unsuitable. Therefore, maybe such a division is not necessary. Additionally, section 4 is too short.

8. The maps of the Figures need units in the colour scales and a description of how the spatial distribution map was compiled.
9. The equations throughout the manuscript need to be numbered and adjusted to follow the journal's template.
10. A "Discussion" section is needed, and a good division of the results is also needed. Some results should be moved and added in a separate section titled "Results".
11. The names of the mining areas should be clarified.

Minor comments:

Abstract

[Line 19] "…is taken as the object." The sentence needs to be improved.

[Lines 19-21] The sentence needs to be more comprehensive.

[Line 24] "…results closer to the actual situation." The sentence needs to be further explained.

[Line 25] An explanation of the mentioned MapGIS is needed. "established"? Is there a more suitable word?

1. Introduction

 

[Figure 1] The following improvements should be incorporated into the map of Figure 1: a) the faults symbol should be a line and not an area, b) The river symbol should be the same on the map as in the legend, c) "Mining area" and "Mine area": they should be the same in the legend and map, d) What kind of Boundary is shown? f) Figure 1 needs to be mentioned in the text.

[Figure 2] The fault symbol should be improved (to be a line); it seems like a weakness zone. Is the scheme a generic one or a specific one for the study area? If it regards the study area, a scale and a legend for the geological formations could be helpful.

 

2. Materials and Methods

 [Lines 162-163] The expressions could be depicted better with equations.

3. Determination of Influence Weight

 [Figure 9] The caption of the Figure needs to be improved to be more comprehensive.

5. Assessment of Water Inrush Risk of Coal Floor

 [Figure 10] The title in the chart is not needed. Units?

 

[Figures 11 & 12] The colour scales need units. Which coordinate system is used in the maps?

6. Conclusions

 General note: They must be improved by focusing on the original contribution of the research.

Author Response

Response to Reviewer 4 Comments

Please refer to the attachment for the specific modification of the article.

Point 1: The title of the manuscript should be improved; it should be shorter, more informative, and attractive. For example, the title's words "Coupling Based" are not comprehensively composed. In addition, keywords such as "coal mine" could be added to the title to represent the manuscript's context better.

Response 1:The title of the article was changed to "Risk assessment of water inrush of coal seam floor based on combined empowerment method".[Line 2-3]

Point 2: The abstract needs to be improved to be more informative regarding the case analyzed and the main extracted results.

[Line 19] "…is taken as the object." The sentence needs to be improved.

[Lines 19-21] The sentence needs to be more comprehensive.

[Line 24] "…results closer to the actual situation." The sentence needs to be further explained.

[Line 25] An explanation of the mentioned MapGIS is needed. "established"? Is there a more suitable word?

Response 2: Numerous modifications have been made, including the selection of water inrush factors and the advantages of a combination of empowerment methods, and the results are discussed.[Line 16-29]

Point 3: Each one of the keywords should be shorter.

Response 3: Key words: water inrush; Entropy weight; Improved fuzzy analytic hierarchy process; evaluation model; Safety evaluation

Point 4: The literature review needs to be more critical.

Response 4: The literature review is enriched, increasing the advantages of the combination of empowerment methods and the selection of factors affecting the water inrush.[Line 81-111]

Point 5: The English language needs to be improved throughout the manuscript.

Response 5: The manuscript content of the article was revised in terms of English language.

Point 6: A separate paragraph that will describe the innovative contribution of the manuscript and the research gap should be included in the "Introduction" section. Subsections 1.1 and 1.2 could be moved to the "Materials and Methods" section.

Response 6: The paragraphs have been reworked.

Point 7: The sections of the manuscript should follow the journal's template. Furthermore, subsection "2.1 Aquifer" is not described, and the title is unsuitable. Therefore, maybe such a division is not necessary. Additionally, section 4 is too short.

Response 7: Secparts of the manuscript were redivided following the journal template and enriched in Section 4.

Point 8: The maps of the Figures need units in the colour scales and a description of how the spatial distribution map was compiled.

[Figures 11 & 12] The colour scales need units. Which coordinate system is used in the maps?

Response 8: The colour scales have units. The China geodetic coordinate system 2000 used in both figures 11 and 12.

Point 9: The equations throughout the manuscript need to be numbered and adjusted to follow the journal's template.

Response 9: The equations in the manuscript have been re-numbered and adjusted.

Point 10: A "Discussion" section is needed, and a good division of the results is also needed. Some results should be moved and added in a separate section titled "Results".

Response 10: The article readjusted the paragraphs as required by the journal and added the results and discussion.[Line 345] [Line 385]

Point 11: The names of the mining areas should be clarified.

Response 11: The name of the mine in the figure has been remarked, for example, Figure 1.[Line 145]

Point 12:

Introduction

[Figure 1] The following improvements should be incorporated into the map of Figure 1: a) the faults symbol should be a line and not an area, b) The river symbol should be the same on the map as in the legend, c) "Mining area" and "Mine area": they should be the same in the legend and map, d) What kind of Boundary is shown? f) Figure 1 needs to be mentioned in the text.

[Figure 2] The fault symbol should be improved (to be a line); it seems like a weakness zone. Is the scheme a generic one or a specific one for the study area? If it regards the study area, a scale and a legend for the geological formations could be helpful.

Response 12: [Figure 1] a)The fault legend was modified, both lines represent the upper and lower fault discs, respectively. b)The river colors on the map has been reworked. c) All changed to “mining area”.d) The boundaries of coal mines.

[Figure 2] The figure is a schematic diagram of the water inrush of coal seam floor, which is universal. The fault symbols were remodified.[Line 167]

Point 13:  [Lines 162-163] The expressions could be depicted better with equations.

Response 13: The expression has been expressed in equations.[Line 196-203]

Point 14: [Figure 9] The caption of the Figure needs to be improved to be more comprehensive.

Response 14: The proposed water inrush of coal seam floor safety evaluation index.

Point 15: [Figure 10] The title in the chart is not needed. Units?

Response 15: The title in the chart has been deleted, and the data in the chart has no units.

Point 16: General note: They must be improved by focusing on the original contribution of the research.

Response 16: It deepens the analysis of the contribution to the mining area.

Please refer to the attachment for the specific modification of the article.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The revised manuscript is quite improved. Authors have put their efforts into improving the overall quality of the manuscript. However, there is still confusion about the changes made as shown in the PDF and the Editable versions provided by the authors.

Please explain what are the "empowerment results" in the abstract?

The authors stated that the improved fuzzy analytic hierarchy process is simpler than the analytic hierarchy process algorithm. It is unclear which of them is without the consistency test of the judgment matrix and how the weight is more reasonable. In literature, there is the same fuzzy AHP approach; how do authors call it an improved one?

In response to point 4, the authors claimed that they have made a comparative analysis of AHP and other methods and discussed their differences. However, there have been no changes in the manuscript based on the literature.

In response to point 6, the literature on developing an evaluation index lacks. Moreover, it is still not clear how the index is developed and how the AHP is improved with integration with Grey Theory; the importance of evaluation index research in mining; how the evaluation index is integrated into the decision support system and how Fuzzy AHP is used with other methods, and how the evaluation index is constructed according to well-established models.

It is requested that mention the exact line numbering while referring to changes made by authors.

Please write responses according to the changes made. The authors' responses do not match the changes they made in the manuscript.

In the attached, I have proofread the article. I hope it will help improve the linguistic errors in the manuscript. Looking forward to seeing the finalized manuscript very soon. Good Luck!

Comments for author File: Comments.pdf

Author Response

Point 1: Please explain what are the "empowerment results" in the abstract?

Response 1: The empowerment result refers to the weight determined by the improved analytic hierarchy process for each factor.The article has changed "empowerment results" to “the weighting results”.

Point 2: The authors stated that the improved fuzzy analytic hierarchy process is simpler than the analytic hierarchy process algorithm. It is unclear which of them is without the consistency test of the judgment matrix and how the weight is more reasonable. In literature, there is the same fuzzy AHP approach; how do authors call it an improved one?

Response 2: In the introduction, I explained the analytic hierarchy process, fuzzy analytic hierarchy process and improved fuzzy analytic hierarchy process again, and pointed out their advantages and disadvantages. See lines (90-118) for specific discussion. The advantages of the improved analytic hierarchy process are mainly reflected in the algorithm. For the specific contents, please refer to the calculation process in section 2.3.1. On the point that the weight result of IFAP is more reasonable, I compare the weight result of AHP with that of IFAHP and draw a conclusion. See lines (325-331) for specific discussion.

Point 3: In response to point 4, the authors claimed that they have made a comparative analysis of AHP and other methods and discussed their differences. However, there have been no changes in the manuscript based on the literature.

Response 3: In the introduction, I discussed the advantages and disadvantages of the combination of analytic hierarchy process and fuzzy analysis and the combination of analytic hierarchy process and grey theory. See lines (93-106) for details.

Point 4: In response to point 6, the literature on developing an evaluation index lacks. Moreover, it is still not clear how the index is developed and how the AHP is improved with integration with Grey Theory; the importance of evaluation index research in mining; how the evaluation index is integrated into the decision support system and how Fuzzy AHP is used with other methods, and how the evaluation index is constructed according to well-established models.

Response 4: I have consulted the literature you provided and analyzed the previous research on the establishment of evaluation indicators in mining. I revised the article and added the references you provided. See lines (262-285) for specific discussion.

Thank you very much for your continuous attention to the manuscript and put forward very useful suggestions. In the process of revision, I feel that there are many deficiencies in the manuscript, but with your help, the content of the article is richer. I am also trying to improve the manuscript from time to time. If there are still deficiencies, please criticize and correct. Finally, thank you again for your help!

Sincere greetings

Author Response File: Author Response.pdf

Reviewer 4 Report

In the revised edition, the manuscript has been significantly improved. However, a further improvement would be expected, referring to the new information regarding the spatial analysis and the original approach to the problem. In this framework, I agree with the suggestions of Reviewer 1.

Some additional specific comments and recommendations for improving the manuscript are noted below.

1. The symbols of the parameters should be the same in the equations, and the text
2. Further editing is needed

Author Response

Point 1:In the revised edition, the manuscript has been significantly improved. However, a further improvement would be expected, referring to the new information regarding the spatial analysis and the original approach to the problem. In this framework, I agree with the suggestions of Reviewer 1.

Response 1: I have revised the manuscript according to reviewer 1.

Point 2: The symbols of the parameters should be the same in the equations, and the text.

Response 2: I have checked the formula parameters in the manuscript and the article, and found no great difference. If there is any difference, I hope you can put forward it.

Point 3:Further editing is needed

Response 3: In the future, I will let the editorial service of the journal help improve the English language of the manuscript, and modify the content of the manuscript according to the opinions of the reviewers and editors.

Thank you very much for your continuous attention to the manuscript and put forward very useful suggestions. In the process of revision, I feel that there are many deficiencies in the manuscript, but with your help, the content of the article is richer. I am also trying to improve the manuscript from time to time. If there are still deficiencies, please criticize and correct. Finally, thank you again for your help!

Sincere greetings

Author Response File: Author Response.pdf