Waterway Channel Stability and Management Measures of Chenglingji—Wuhan Reaches in the Middle Section of the Yangtze River

Round 1

Reviewer 1 Report (Previous Reviewer 2)

The paper studies the Waterway Channel Bathymetry and Management Measures. Overall, the paper is written well, however, few comments should be considered before accepting the paper for publication.

-        Page 1, lines 28-32. This paragraph needs to rewrite. Also, please add reference.

-        Same comment for the paragraph lines 34-40.

-        The novelty of the study should be highlighted better in the last paragraph of introduction.

-        Line 80. Write the full word approximately.

-         Figure 1. not clear

-        Section 2.3 needs to improve.

-        The results of the study are floating. All results and discussion should be improved and compared with previous studies. It is not enough to report your results without comparing with previous results.

-  -        The quality of Figure 1 is not clear. Should be improved.

-        Figure 2, similar comment.

-        Conclusion should be summarized better. I suggest to write the main conclusion as bullets.

Author Response

The paper studies the Waterway Channel Bathymetry and Management Measures. Overall, the paper is written well, however, few comments should be considered before accepting the paper for publication.

Reply: Thank you for your recognition.

1. Page 1, lines 28-32. This paragraph needs to rewrite. Also, please add reference.

Reply: The research significance is further sorted out and references are added.

2. Same comment for the paragraph lines 34-40.

Reply: Changed the expression of semantics.

3. The novelty of the study should be highlighted better in the last paragraph of introduction.

Reply: The results of this study are of great value in guiding waterway planning and river management, etc. The novelty of the study and the problems faced by the study area are further highlighted in the revision.

4. Line 80. Write the full word approximately.

Reply: Changed the language expression.

5. Figure 1. not clear.

Reply: Improved the clarity of Figure 1.

6. Section 2.3 needs to improve.

Reply: Sorted out the structure of the article and checked the full text for English.

7. The results of the study are floating. All results and discussion should be improved and compared with previous studies. It is not enough to report your results without comparing with previous results.

Reply: Improved the study results and discussion section to further highlight the novelty of the study by comparing it with previous studies.

8. The quality of Figure 1 is not clear. Should be improved.

Reply: Improved the clarity of Figure 1.

9. Figure 2, similar comment.

Reply: Changed the presentation of Figure 2 and changed the annotation.

10. Conclusion should be summarized better. I suggest to write the main conclusion as bullets.

Reply: Improved research results and discussion section to focus on the main innovative results achieved.

Author Response File: Author Response.docx

Reviewer 2 Report (Previous Reviewer 1)

This is an “engineering”, not a scientific article. The aim was to “analyze waterway flushing and siltation characteristics” which is very often a part of water infrastructure design. Metrology is very well known, and this paper has no new idea. The only advantage I see in this article is the publication of monitoring data from this reach.

Row 186 and 187 and Fig6. Did you perform any statistical calculations to say that is no trend? Can you give statistical measures? Visually, there is a decrease in runoff and sediment at Hankou which seem to start from around 1986.

Table 3 Why you chose 1980 to split periods? What reasons?

Author Response

This is an “engineering”, not a scientific article. The aim was to “analyze waterway flushing and siltation characteristics” which is very often a part of water infrastructure design. Metrology is very well known, and this paper has no new idea. The only advantage I see in this article is the publication of monitoring data from this reach.

Reply: The full text has been modified with reference to the opinions of other four reviewers.

1. Row 186 and 187 and Fig6. Did you perform any statistical calculations to say that is no trend? Can you give statistical measures? Visually, there is a decrease in runoff and sediment at Hankou which seem to start from around 1986.

Reply: Changed the description of data analysis. In July 1981, the first unit of Gezhouba Dam hydropower project was put into operation, and the year 1980 was chosen as the demarcation year. The Gezhouba Dam water Conservancy project was completed in December 1988. Under the combined influence of soil and water conservation and climate change in the upper reaches of the Yangtze River, the amount of sediment in Hankou has decreased significantly since 1986.

2. Table 3 Why you chose 1980 to split periods? What reasons?

Reply: In July 1981, the first unit of Gezhouba Dam hydropower project was put into operation, and the year 1980 was chosen as the demarcation year.

Reviewer 3 Report (New Reviewer)

The natural riverine channel plays a significant role in transport of the Suspended Sediment Discharge (SSD), water, and nutrient material, which provide shipping for human economic development. However, due to dredging and decline in SSD, riverine channel experienced drastic alteration from nature to human-made shift. In this study, author analyzed riverbed changes, possible reasons, and further countermeasures. I think that this Ms is well organized with ample data to support present work. However, some shortage could be rectified before ms accepted. Firstly, Chengling-Wuhan reach should be impacted from decline in SSD from Dongting lake, some discussion wants to be supplied (See Yu et al. Journal of Hydrology, 2018, 562, 254-266; Dai et al., Journal of Hydrology, 2018, 566, 719-734); Meanwhile, riverine island between Chengling-Wuhan reach could experience drastic changes with impacts from different magnitude in runoff and SSD (See Lou et al., Catena, 2022, 217, 106488), some expansion wants to be done. Moreover, present title I suggest that it can be revised as  “Waterway channel stability and management measures of the Chenglingji-Wuhan reach in the middle section of the Yangtze River”. I thereof recommend it to be accepted after revision.

Author Response

1. The natural riverine channel plays a significant role in transport of the Suspended Sediment Discharge (SSD), water, and nutrient material, which provide shipping for human economic development. However, due to dredging and decline in SSD, riverine channel experienced drastic alteration from nature to human-made shift. In this study, author analyzed riverbed changes, possible reasons, and further countermeasures.

Reply: Thank you for your recognition.

2. I think that this Ms is well organized with ample data to support present work. However, some shortage could be rectified before ms accepted. Firstly, Chengling-Wuhan reach should be impacted from decline in SSD from Dongting lake, some discussion wants to be supplied (See Yu et al. Journal of Hydrology, 2018, 562, 254-266; Dai et al., Journal of Hydrology, 2018, 566, 719-734);

Reply: Further inquiry of recent research literature enriches the discussion.

3. Meanwhile, riverine island between Chengling-Wuhan reach could experience drastic changes with impacts from different magnitude in runoff and SSD (See Lou et al., Catena, 2022, 217, 106488), some expansion wants to be done.

Reply: Further inquiry of recent research literature enriches the discussion.

4. Moreover, present title I suggest that it can be revised as “Waterway channel stability and management measures of the Chenglingji-Wuhan reach in the middle section of the Yangtze River”.

Re: Corrected article title.

5. I thereof recommend it to be accepted after revision. 

Reply: Thank you for your recognition.

Author Response File: Author Response.docx

Reviewer 4 Report (New Reviewer)

The paper addressed the important issue of river morphological adaptation downstream of the Three Gorges Dam in the Yangtze River, based on  comprehensive data analysis. The findings have broad implications for managing the waterway. The paper is well organized and prepared. I suggest it for publication after minor revision. The only problem is the the language can be better improved to make it more easier to follow.

Author Response

The paper addressed the important issue of river morphological adaptation downstream of the Three Gorges Dam in the Yangtze River, based on  comprehensive data analysis. The findings have broad implications for managing the waterway. The paper is well organized and prepared. I suggest it for publication after minor revision. The only problem is the the language can be better improved to make it more easier to follow.

Reply: Thank you for your recognition. Language changes and polish were made in the revision.

Author Response File: Author Response.docx

Reviewer 5 Report (New Reviewer)

The paper requires major revisions:

1-How did authors compute volume of the scour hole in this paper as seen in "Calculation of riverbed scouring and deposition volumes"? As a suggestion, this section needs reference.

2-Which software was use to validate the field data? Authors need to add more clarifications!

3-What are accuracy of validation process as seen in the following references??

Riprap incipient motion for overtopping flows with machine learning models

4-Did authors check out uncertainty analysis of validation process??

Author Response

1. 1. How did authors compute volume of the scour hole in this paper as seen in "Calculation of riverbed scouring and deposition volumes"? As a suggestion, this section needs reference.

Reply: In this study, the total erosion and sedimentation of the riverbed are calculated. If the scour and siltation amount of riverbed in local areas is calculated, grid calculation is generally adopted. For further reference, Wang, J.J,; Yang, Y.Y,; Zhang, M,J,; Zhu, L.L,; Li, S.W,; Wen, Y.C. Critical threshold of periodic point bar scour and sediment body transport path in tidal reaches: A case study of Fujiangsha reach, Yangtze River. Journal of Geographical Sciences, 2023, 33(6): 1334-1358. The literature carries on. Some commercial software can also be used for calculation, such as Civil 3D.

2. 2. Which software was use to validate the field data? Authors need to add more clarifications!

Reply: The information of monitoring instrument and accuracy of measured data is added.

3. 3. What are accuracy of validation process as seen in the following references?? Riprap incipient motion for overtopping flows with machine learning models.

Reply: Reviewed the full text.

4. Did authors check out uncertainty analysis of validation process??

Reply: The expression of quantitative data in the full text was checked, and the uncertainty of the data was checked.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report (Previous Reviewer 1)

no other comments

Author Response

Thank the reviewers for their recognition.

Author Response File: Author Response.pdf

Reviewer 5 Report (New Reviewer)

The authors are strongly recommended to address the reviewers' comments point by point and applied them into revision.

Author Response

1-How did authors compute volume of the scour hole in this paper as seen in "Calculation of riverbed scouring and deposition volumes"? As a suggestion, this section needs reference.

Reply: In this study, the erosion and sedimentation of the riverbed below the characteristic water level were calculated by using the section method. Yang et al., 2022. The volumes of the bank and deep channel are calculated using the grid method, The calculation process and model generalization diagram are given in the revision (see Figure 3 of the revised draft for details).

2-Which software was use to validate the field data? Authors need to add more clarifications!

Reply: Acoustic Doppler Current Profilers (ADCP) was used for velocity and flow test, Differential Global Navigation Satellite System (DGNSS) positioning and Global Navigation Satellite System (GNSS) compass for track correction and bow correction. ADCP current measuring system adopts RDI-BBADCP (Research Development International –Broad-band ADCP) series 300 kHz, 600 kz and 1,200 kz instruments, and the data acquisition software version is WinRiver-II 2.20/2.18. The sediment content of suspended mass was tested by filtration drying weighing method and 1/10,000 electronic balance was used for weighing.

3-What are accuracy of validation process as seen in the following references??

Reply: The reference "Riprap incipient motion for overtopping flows with machine learning models" is added and the accuracy of the validation process is analyzed.

4- Did authors check out uncertainty analysis of validation process??

Reply: Added measuring instruments and uncertainty, and further comb the full text.

Author Response File: Author Response.pdf

Round 3

Reviewer 5 Report (New Reviewer)

accept as is

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

I could not find much science in this article. Most of the paper is a description of a typical engineering investigation for securing a waterway. In the introduction, the aim of this paper is just a description of waterway flushing and siltation characteristics for this case, which is of course interesting but very local. In the first sentence of the conclusion, however, the author wrote about the relationship between the changes in riverbed siltation, continental beach morphology, branching channel divergence relationship, and the degree of obstruction of navigation. Unfortunately, I could not find any description (equation) of the relationship in the text. 

It is tough to review and give detailed comments because most of the data and descriptions are actually measured data. The only I can say is to trust the data you presented here because it is not possible to check the reality of this data. 

To be more clear please indicate the direction of flow in Fig.1 b

Author Response

I could not find much science in this article. Most of the paper is a description of a typical engineering investigation for securing a waterway. In the introduction, the aim of this paper is just a description of waterway flushing and siltation characteristics for this case, which is of course interesting but very local. In the first sentence of the conclusion, however, the author wrote about the relationship between the changes in riverbed siltation, continental beach morphology, branching channel divergence relationship, and the degree of obstruction of navigation. Unfortunately, I could not find any description (equation) of the relationship in the text. 

Reply: It supplements the scientific nature of the research and the basis of calculation simultaneously; The effect of shunt ratio on obstructing navigation condition is mainly reflected in that the reduction of shunt ratio is not conducive to the stability of the dynamic condition of the main channel. Non-main channel flushing volume or strength is large, which is not conducive to the stability of the main channel.

（1）It is tough to review and give detailed comments because most of the data and descriptions are actually measured data. The only I can say is to trust the data you presented here because it is not possible to check the reality of this data. 

Reply: The topographic data was measured by laser method with a scale of 1:10000, which supplemented the calculation process of riverbed erosion and sedimentation. The Acoustic Doppler Current Profiler (ADCP) was used to measure the shunt ratio, complementing the monitoring method of sectional flow.

（2）To be more clear please indicate the direction of flow in Fig.1 b

Re: Added water flow direction.

Reviewer 2 Report

The paper studies the Waterway Channel Bathymetry and Management Measures: A Case Study of the Chenglingji–Wuhan Reach in the Middle Reaches of the Yangtze River. Overall, the paper is written well, however, a few comments should be considered before accepting the paper for publication.

1. abstract should be revised very well. focus on the main findings and add one sentence as a conclusion of the study.

2. The novelty of the study should be highlighted better in the last paragraph of introduction.

3. Section 3.1: Can you put the data in a table?

4. I recommend to add some statistical analysis for the section 5

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear authors,

The manuscript is well written and well organized, but from my point of view is not a scientific  paper but a detailed technical description oriented towards solving an important localized problem ( to ensure river navigation in the middle reaches of the Yangtze River).

Too many technical details, concerning the survey methods to acquire riverbed morphology, are missing. For instance, in line 95 only a short reference to a laser method is provided, but more details need to be included to be considered.  Which equipment have been used? How long did the field work last? After data acquisition how the points (?) were transformed into surface for all the analyzed years? The results were calibrated? What are the limitations ?

Also, the technical aspects of governance, the ecological aspects and dredging maintenance aspects are poorly detailed.

Authors should resubmit the work, after including the technical detail necessary for a complete understanding of the work and so that it can be replicated in other locations.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf