Evolution of Hydrological Conditions and Driving Factors Analysis of the Yongding River in a Changing Environment: A Case Study of the Xiangshuipu Section
Round 1
Reviewer 1 Report
1. The paper studies the current situation, which can be improved by expecting future consequences.
2. The abbreviations along the text should be clarified.
The English language needs minor improvement
Author Response
Point 1: The abbreviations along the text should be clarified.
Response 1: Thanks for the suggestion. All abbreviations have been clarified in the manuscript.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear Authors,
Thanks for this important work right now because climate change affects everything related to human life such as the agriculture sector, water resources, groundwater water consumption food supply... etc.
Please respond to these comments to improve this work.
Introduction:
Line 43. The RVA. Where is the definition of it? you have to define it.
Line 44. IHA. Where is the definition of it? you have to define it.
line 63. 938,000 acres. you have to change it to a Metric unit.
line 70. the IHA-RVA method. Where is the definition of it? you have to define it.
The introduction needs more references related to climate change such as temperature, precipitation, interception, snowmelt, depression, infiltration, 141 evapotranspiration, surface runoff, subsurface runoff, groundwater, deep percolation, etc.., and irrigation methods used in the regimes.
Methodology.
Did measure the groundwater level and (subsurface runoff) beside the river and how if yes where is it or not?
what is the structure of the river? Is building water flow directly on clay or sandy soil or cement channel? Did you measure the soil infiltration if yes where is the data?
Did you notice the varieties of plants growth on the river on both sides if yes, did you describe them and measure the evaporation from the leaves of the plant and the water surface?
You have to describe the IHA-RVA method in more detail.
You have to describe the WetSpa model with more description.
The result and discussion part need more description and reason.
The conclusion
you have to focus on your conclususion of the major result such as agriculture water use, climate change impact, and how you can reduce this impact by using modern irrigation technology to reduce agriculture water use and climate change. You find that half of the water amount in the river is used for agriculture. you have to find a way to reduce this amount how to complete this work and become more useful for the readers and researchers.
How you can make the ecological hydrology system sustainable for all the users/ That is what you must conclude at the end of this study.
Greetings
You have to improve the English language.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 3 Report
General Comments
This study adapted the IHA-RVA method to analyze hydrological alterations of Xiangshuipu section of Yongding River. This is a case study relevant to sustainable use of water resources. In this work, the original IHA-RVA method was modified, which can potentially be an innovative idea. It’s a pity that details of the modification were not explained well. The experiment has sufficient amount of data to report, and the conclusions could potentially contribute to the current knowledge of engineering. However, the description of methodology and experiment design is vague and very hard to interpret. At this point it is not clear whether this is a systematic failure of experiment design, or is it the fault of poor scientific writing.
I would suggest that the authors answer to the following questions to support their methodology and improve their English writing. Whether this paper can be published should be decided after reviewing the revised version.
Detailed Comments:
1. Introduction Line 34 ‘Hydrological conditions refer to changes in the hydrological elements…’
Do you mean ‘hydrological alterations’ instead of ‘hydrological conditions’ ?
2. Introduction, Lines 38-44
Pleas give full name when an abbreviation appears in your text for the first time. In this paragraph, please spell out full names of ‘IHA’ and ‘RVA’.
3. Introduction, Line 47 ‘Related studies have shown that runoff from major river basins in China varies.’
I would instead say ‘climate change and human activities impact river basins in China in different ways’, so that this sentence better connect the previous sentence and the -following review. It also more clearly states your interest to explore the impacts of different factors in Xiaoliangpu.
4. Introduction Lines 67-68 ‘The upstream Xiangshuipu was set as the assessment section…’
Is there any specific reason that Xiangshuipu section was selected for assessment?
5. There are a few things about Figure 1
a) The Sanggan River is unclear. There are so many blue lines in the map, are they all representing Sanggan river?
b) In ‘The Yongding River Basin’ map, there are two grey lines. What are these and are they necessary?
c) In this study the boundaries of provinces are less relevant. It might be better if you use a satellite map showing the geography of your river basin, the sub catchments of the two tributaries, or a map marking out the irrigated land.
d) Is the third sub map your area of research? What exactly does ‘Xianghuipu section’ mean? Please specify on map.
e) If you decide to keep province boundaries: To the right-most part of the map there is a short yellow line, and to the north of this line, there is a blank space and a pink-brown line (color representing Zhangjiakou). What is this space?
6. Section 2.1
a) I am not understanding why provinces and the Haihe River need to be mentioned here.
b) Lines 91-92 ‘the demand for agricultural water is extremely high, precipitation is scarce, and evaporation is considerable…’ These descriptions are vague. Please state numbers for irrigation needs and evaporation, or net water loss, to support your descriptions.
7. Section 2.2 Line 100 ‘and other related data’
What related data?
8. Table 1
a) in the second column first line. For these 12 parameters, some researchers use ‘mean’ and some use ‘median’. What is your reference here?
b) Speaking of references, your listed references 4, 5 (mentioned in Line 36 in Introduction), and 35 (line 119) are not from Richter and does not provide any information about IHA or RVA. Please update.
9. Section 3.2 Lines 153-154 ‘Therefore, the inflow rate of the Xiangshuipu Reservoir was determined, and …’
This is vague. What does ‘determine’ mean? Did you have inflow rates recorded from the field, or do you calibrate the model and generate inflow rates? Also, what does ‘considered simultaneously’ mean?
10. Figure 3 and Section 3.2 Lines 154-155
a) Firstly, please give equation for RB calculation to avoid misunderstandings.
b) RB is not the only criteria, or even the most effective criteria, to evaluate simulation results. Although your results have low RB values, it’s clear from Figure 3 that the timing and flow rates of peaks are significantly different. Why did you not consider Nash-Sutcliff Efficiency coefficient, or peak-weighted RMSE to evaluate your results? The current Figure 3 is not convincing that you have a good enough simulation.
c) For the caption I would provide more detailed information by saying ‘Simulated and measured time series of flow rates of Xiangshuipu Reservoir inflow during the rate and verification period’.
d) please indicate the time step used for this simulation.
11. Section 3.3 lines 162-164
What do you mean by ‘assuming that there is only one reservoir upstream’? Are there other reservoirs? I can guess what you are explaining but please rewrite this paragraph so that the information is clear. I suggest that you ask someone from outside your field to proofread your manuscript.
12. Section 3.3 Lines 183-190
This section is very confusing, I suggest you rewrite this paragraph. As examples of my questions:
a) Are Ei1 to Ei3 impacted by ‘variation of climate conditions’ ? What does ‘variation of climate conditions’ mean? Does Ei4 consider reservoir and withdraw?
b) Is Ei3 considering reservoir or withdraw? Does ‘not considering’ means simply removing ∆W or ∆S and L?
c) I don’t understand Eis, and that’s why I am also having a hard time understanding equations 7-9. Please provide effective references to these equations. Or, making a table indicating the included and not included factors for Eis could be helpful. Explaining what positive and negative values of Vis mean can also be helpful.
d) Note the right parenthesis in equation 8.
13. Section 3.3 line 190
Why choosing 3% as a threshold?
14. Figure 5
The second last factor, I think you meant to say ‘fall rate’?
15. Table 3
In Table 3, not any ERHI in group 4 is included.
When I take a closer look at Figure 5, Low pulse duration and High pulse duration are not strongly correlated with maximum or minimum flow rates. Also, average flows in March, April, and May are less correlated with July flows. Why are these ERHIs not selected?
16. Section 4.2 Line 220 ‘First, the Hurst coefficient method…’
a) Please provide effective reference to this method and provide standards for ‘weak’ and ‘medium’ degree of variation.
b) did you test the degree of variation for other ERHIs that are not selected? Is it possible if they are having greater degrees of variation?
17. Table 5
Missing introduction of these methodologies. How was the T-test and Sequential Clustering-test etc. practiced?
18. section 4.3
a) Lines 249-257 Vi1 was too small and was not considered. So, did you use equations 7 to 9 and how did you use them?
b) Lines 259-262 How should we interpret Figure 8(b), especially positive vs negative contribution? Does this figure indicate that climate change is reducing the extent of hydrological alterations? And what exactly does ‘climate change’ mean in your modeling work?
19. section 5.1
a) lines 277-278 ‘The dates of maximum flow were low, indicating that changes in hydrological conditions had little impact on fish migration.’ This sentence is not making sense. Please provide details or references.
b) lines 278-281 ‘The overall hydrological conditions… were stable during the study period.’ This sentence is very strong, especially when ‘ecological environment’ is used.
20. section 5.2 lines 285-286 ‘Both these indicators were in crop-growing period, when agricultural use was higher.’
Did you think of the seasonality of agricultural water when screening ERHIs? Isn’t it apparent that when you analyze July flow, it is reflecting a stronger impact of water withdraw than average flow in winter months? As a result, is it July flow representative of the impacts of human factors on hydrological alteration?
Extensive editing is required.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Greetings,
Thanks for your response.
Author Response
Thanks again to the reviewer for the valuable suggestions.
Reviewer 3 Report
I am very glad to see that the English writing has been improved and the description of methodology is much more clear and logical in the revised manuscript. There are only three minor editions suggested before publication.
1. The 15th citation (paper from Alrajoula) is now marked as 155.
2. regarding Figure 3
2.1 Firstly, thanks for your answer to my questions regarding Figure 3. I do understand that it’s extremely hard to get perfect and comprehensive data from the field. That's also why it's acceptable to have less accurate modeling results.
What is a bit concerning is that looking at the updated Figure 3, it’s clear that the timing and value of peak flows are still quite different. It could be better if one or two sentences are added to persuade the readers on one of the three: a) the timing and value of peaks are not impactful to your later analysis, or b) these ‘errors’ are in an acceptable range, or c) this is the best possible simulation result we can get with the available data.
2.2 It’s interesting to see equation 3. In this equation, (Qmt-QOt) can be either greater than 0 or smaller than 0, and the positive and negative values counteract each other. Not sure if this is why the validated results have a smaller RB when compared to calibrated results.
It’s also possible that you are using the absolut error instead (|Qmt-QOt|), which makes more sense.
3. section 3.3
There’s very little difference between ‘assuming there is one reservoir’ and ‘if there is one reservoir’. From what I understand, delta W describes water withdrawal for irrigation at any point between where upstream inflow (I) is measured and where flow rate (Q) is measured.
Is it better if you skip this explanation and directly describe Figure 4 and Equation 4?
That's all my comments for the revised manuscript. Good work. I look forward to seeing it published.
Cheers
The current manuscript would still benefit from editing on English language.
Author Response
Please see the attachment
Author Response File: Author Response.docx
