Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

Respectfully, suggest that the authors follow these recommendations or review the data:

- Is the altitude difference 6,421 meters? As stated in the description of the study area;

- In Figure 1, consider inserting a Digital Elevation Model as a base on the map;

- In Table 2, the Wulong hydrological station was established in 1995, but the Adopted Data Series column indicates 1966–2024.

- It is necessary to comment on and discuss the role of the dynamic equilibrium associated with suspended sediment load. What environmental changes can be caused by a reduction in CSS?

- Are cascading reservoirs the only cause of the reduction in CSS? Are there any significant agricultural techniques implemented in the upper reaches of the Yangtze River that could contribute to the reduction?

Sincerely,

Comments for author File: Comments.pdf

Author Response

The response to the reviewer and the explanation of revisions are provided in the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The article is generally interesting and useful; it describes in sufficient detail the significant changes in sediment yield in the upper Yangtze River following the construction of several large reservoirs. Aside from minor comments regarding the author's terminology, some of which are listed below, my main concerns revolve around the nature of formulas (4)-(6) and the lack of justification for their use. For example, in the formula 4 the numerator is the second derivative of the annual amount of precipitation with respect to time divided by the first derivative of the annual amount of precipitation with respect to time. The same for the other terms. Can you explain the meaning of such expression? It's difficult to assess why the author needed such a complex framework. The selection of factors influencing sediment yield also raises questions: while precipitation is a clear factor, evaporation has no direct impact on sediment yield. The inflection years for cumulative ET differ significantly of the inflection years of SSL. The inflection years for cumulative P are also not the same as for SSL. The sections 3.41 - 3.43 are not based on the observations. Furthermore, water discharge is not included in formulas (4)-(6). The article would benefit from major revisions to sections 3.4 and 4.3. The conclusion “Human activities play an absolutely dominant role in the reduction of sediment transport in the study area.” is absolutely exact, but can be made without using the formulas 4-6.

 

Minor comments

Please, explain the terms:

 geomorphic time scale

 hydrological time scale

the dynamic transition law of driving factors

the net SSL in the typical intervals – the difference?

anomaly variation curve

cumulative anomaly method (Eq. 1) and the RAPS method (Eq 2) differ only by the constant (Standard Deviation Sy). The fig 3 and 4 bear the same information. The inflection point at 2013 is clear on Fig 4 – distinct change of curve slope.

the author writes: Meanwhile, it can be observed that except for the river section between XJB and Zhutuo Stations, where the degree of reduction in cumulative SSL during the first change period is greater than that during the second change period, the degree of reduction in cumulative SSL at other hydrological stations or river sections gradually intensifies from the first change period to the second change period.

The meaning of this sentence is not clear. All these relationships show the gradual decrease of the annual suspended sediments yield from baseline period to the first change period and to the second change period (except for the river section between XJB and Zhutuo). For example for Fig 6a – 2.513, 1.431 and 0.012 10^6 t/a

Comments on the Quality of English Language

The terminology must be explained

Author Response

The response to the reviewer and the explanation of revisions are provided in the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The article is well written and structured and deserves to be published from my side only minor changes are necessary:

• imporve the quality of the images (DPI)
• report the unit of measures in plots 
• how do you validated your results and how you deal with biases (please report it in the manuscript

Author Response

The response to the reviewer and the explanation of revisions are provided in the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors of the article took all my comments into account. Some comments, with additions, have been incorporated into the text of the article. I have no new comments.