Optimization of Advance Drainage Borehole Layout Based on Visual Modflow

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. Check the format of citations in the text (the authors' guide indicates that they should be cited with numbers)

2. Figure 1 should be accompanied by a location map. Figure 1 should have a legend (which are the blue lines What does f, y mean?)

3. Authors should add information about the validity of their model, including information about the value of its error (error between observed data and calculated data). There are several equations to determine this error and the efficiency of the mathematical model.

If the reviewer knows what that error is, he will be able to analyze in more detail the results obtained.

Author Response

Comments1: Check the format of citations in the text (the authors' guide indicates that they should be cited with numbers)

Response1: We appreciate the reviewer's feedback, We have made improvements to  the original manuscript. The citation format in the text has been changed to numerical citation.

Comments2:  Figure 1 should be accompanied by a location map. Figure 1 should have a legend (which are the blue lines What does f, y mean?)

Response1: Figure 1 has been modified in the original manuscript and a legend has been added. In order to ensure that groundwater can be effectively drained before coal mining and ensure the safety of coal mine work. Advance drainage drilling in coal mine working face usually drills holes in different directions in the same drilling nest. The blue line segments with arrows in Figure 1 are drainage boreholes in different directions. F stands for the hydrophobic drilling holes laid on the air duct of 3085 working face, and Y stands for the hydrophobic drilling holes laid on the transportation channel of 3085 working face.

Comments3: Authors should add information about the validity of their model, including information about the value of its error (error between observed data and calculated data). There are several equations to determine this error and the efficiency of the mathematical model.

Response3: We appreciate the reviewer's feedback，For this problem, the observed and calculated values of water level in Dongguan 55 borehole are supplemented below Figure 6 of the original manuscript. By calculating the error and error rate between the observed value and the calculated value, it is known that most of the error values are controlled within 5m, and the maximum error rate is only 1.63%. In the numerical simulation of groundwater flow, the water level of this model fits well.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

1. Figure 1 is not clear enough.

2. In Figure 6, there is no proper matching between the two models and the difference between the models is large, how do you claim that the matching is good?

3. What are the initial conditions and boundary conditions in the established numerical model?

4. It is suggested that the conclusion section be rewritten and the results are completely extracted from the manuscript.

5. Some of the data should be included in the appendix of the manuscript, and it should be mentioned where and how the data was obtained.

6. Line 140, it is said that 7 parameters affect water yield of hydrophobic borehole, It is not explained and it is not mentioned in the manuscript that what was the range of changes of these 7 parameters in the study, For example, what was the lower limit and upper limit of borehole orientation and borehole inclination in the investigated data? It is better to include the model inputs and their range of changes in a table, and some of the data should be included in the appendix of the manuscript.

7. The dimensions of the mesh and the size of the studied domain are effective on the results, before performing the numerical analysis, a sensitivity analysis should be performed on these two dimensions, such a thing is not given in the numerical model section, and the effect of the mesh size on the results is not discussed.

8. Again, in the numerical model section, the discretized form of the equation and the algorithm and numerical solution procedure of the equations that have been solved are not given. In this respect, the article is incomplete and cannot be review.

Author Response

Comments1:  Figure 1 is not clear enough.

Response1: We appreciate the reviewer's feedback, we have made improvements to the original manuscript. Figure 1 has been modified in the original manuscript and a legend has been added. In order to ensure that groundwater can be effectively drained before coal mining and ensure the safety of coal mine work. Advance drainage drilling in coal mine working face usually drills holes in different directions in the same drilling nest. The blue line segments with arrows in Figure 1 are drainage boreholes in different directions. F stands for the hydrophobic drilling holes laid on the air duct of 3085 working face, and Y stands for the hydrophobic drilling holes laid on the transportation channel of 3085 working face.

Comments2:  In Figure 6, there is no proper matching between the two models and the difference between the models is large, how do you claim that the matching is good?

Response1: We appreciate the reviewer's feedback，in the numerical simulation of groundwater flow, it is difficult to achieve the complete consistency between the observed and calculated values of water level in long observation holes by generalizing the actual hydrogeological conditions. Due to the limitation of Modflow software, the coordinate axis cannot be modified, and the derived water level fitting curve looks different. For this problem, the observed and calculated values of water level in Dongguan 55 borehole are supplemented below Figure 6 of the original manuscript. By calculating the error and error rate between the observed value and the calculated value, it is known that most of the error values are controlled within 5m, and the maximum error rate is only 1.63%. In the numerical simulation of groundwater flow, the water level of this model fits well.

Comments3: What are the initial conditions and boundary conditions in the established numerical model?

Response3: By collecting the geological data and hydrogeological data of the study area, the initial conditions and boundary conditions of the numerical model are generalized, which are described in detail in two parts: Model boundary condition and generalization of aquifer and aquifer in the manuscript.

Comments4: It is suggested that the conclusion section be rewritten and the results are completely extracted from the manuscript.

Response4: We appreciate the reviewer's feedback, the conclusion of the manuscript has been summarized again.

Comments5: Some of the data should be included in the appendix of the manuscript, and it should be mentioned where and how the data was obtained.

Response5: We supplemented the original data and submitted it in the appendix. The original data comes from Donghuantuo Coal Mine of Kailuan Group, which is mentioned in the original Acknowledgments.

Comments6: Line 140, it is said that 7 parameters affect water yield of hydrophobic borehole, It is not explained and it is not mentioned in the manuscript that what was the range of changes of these 7 parameters in the study, For example, what was the lower limit and upper limit of borehole orientation and borehole inclination in the investigated data? It is better to include the model inputs and their range of changes in a table, and some of the data should be included in the appendix of the manuscript.

Response6: To explore the influencing factors of water output of drainage boreholes, this paper studies 43 advanced drainage boreholes in combination with the hydrological ledger of 3085 working face in Donghuantuo Coal Mine. The data performance of 43 advanced drainage boreholes has been supplemented in the appendix.

Comments7: The dimensions of the mesh and the size of the studied domain are effective on the results, before performing the numerical analysis, a sensitivity analysis should be performed on these two dimensions, such a thing is not given in the numerical model section, and the effect of the mesh size on the results is not discussed.

Response7: The size of the grid and the size of the studied area do have an impact on the results, but this paper focuses on the influence of different locations of advanced drainage holes on the drainage effect. An initial numerical model is established for the same study area with the same grid size. On the basis of this model, only the position of drainage holes is changed, and the drainage effect before and after the hole position change is compared, and suggestions for optimizing the drilling layout are put forward. Therefore, the size of the grid and the size of the studied area are not discussed in the manuscript.

Comments8:  Again, in the numerical model section, the discretized form of the equation and the algorithm and numerical solution procedure of the equations that have been solved are not given. In this respect, the article is incomplete and cannot be review.

Response8: We appreciate the reviewer's feedback, we have made improvements to the original manuscript. The numerical model formula and its solution are supplemented in the establishment a numerical model of ground water flow.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

 The paper is currently lacking the standard structure expected in a research manuscript, including the following key sections:

Introduction

Materials and Methods

Results

Discussion

Conclusions

Additionally, the figures provided are unclear and do not include essential data, which further impacts the quality and clarity of the manuscript. In particular, Figure 6, which presents the curve comparing the fitting calculation of the water level with the actual change in water level, is especially problematic and requires significant revision.

 

 

Comments on the Quality of English Language

I am writing to express concerns regarding the manuscript. The paper is very poorly written and extremely difficult to understand.

Author Response

Comments1:Additionally, the figures provided are unclear and do not include essential data, which further impacts the quality and clarity of the manuscript. In particular, Figure 6, which presents the curve comparing the fitting calculation of the water level with the actual change in water level, is especially problematic and requires significant revision.

Response1: We appreciate the reviewer's feedback, we have made improvements to the original manuscript.In the numerical simulation of groundwater flow, it is difficult to achieve the complete consistency between the observed and calculated values of water level in long observation holes by generalizing the actual hydrogeological conditions. Due to the limitation of Modflow software, the coordinate axis cannot be modified, and the derived water level fitting curve looks different. For this problem, the observed and calculated values of water level in Dongguan 55 borehole are supplemented below Figure 6 of the original manuscript. By calculating the error and error rate between the observed value and the calculated value, it is known that most of the error values are controlled within 5m, and the maximum error rate is only 1.63%. In the numerical simulation of groundwater flow, the water level of this model fits well. At the same time, the original data of drainage borehole and the numerical model formula and its solution for establishing groundwater flow model are supplemented.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I appreciate to the authors that have made efforts in response to the reviewer comments. The authors have addressed the comments raised in my previous review. Considering the revised version, this manuscript is recommended for publication.

Reviewer 2 Report

Comments and Suggestions for Authors

There is no comment 

Reviewer 3 Report

Comments and Suggestions for Authors

changes improved the manuscript