Review Reports - Study of the River Discharge Alteration

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Line 124, Figure 3(a)the frequency more than 100, what is the frequency mean? “wrong”?

If the rainfall data could be shown, the analysis can be more reliable.

1.Line 258, S1 and S2 are both shown an increasing trend, but all series S could not be rejected. It should be noted that an issue “Why these results presented?”. Need more discussions.

2.Line 318, Why only S and S2 are used in HWMDM?

3.Figure 9. The range of forecasting in S and S2 are large and unbelievable results, even with the confidence levels of 80% or 95%. Specially, the discharge is smaller or much smaller zero. I cannot agree with the Holt-Winters Multiplicative Decomposition Model is good enough in this study. Furthermore, is the forecasting necessary in this study?

4.In comparison, all scale of Y-asix should be in the same range if possible, such as Figure3.

Author Response

Dear Reviewer,

Thank you for the time spent reviewing the article and the valuable suggestions that helped improve the manuscript. Please see below the answers to your remarks, in red.

Line 124, Figure 3(a) the frequency more than 100, what is the frequency mean? “wrong”?

The histogram is built with the intervals of values on the Ox axis and the absolute frequency of apparition on the Oy axis. The absolute frequency is the number of values recorded by the variable (in our case, the river discharge) situated in a certain interval. For example, in Figure 3(a), there are 180 values in the interval [0,10), 210 values in the interval [10,20), etc.

If the rainfall data could be shown, the analysis can be more reliable.

Thank you for the suggestion. We agree. We shall try to get the precipitation data. We currently have no access to it, given that it is not publicly available. We shall ask for permission from The National Institute of Meteorology, but it will take time to get approval. Still, we added the idea that a study analyzing the correlation between precipitation-discharge would be further performed.

Line 258, S1 and S2 are both shown an increasing trend, but all series S could not be rejected. It should be noted that an issue “Why these results presented?.”Need more discussions.

Thank you for the suggestion. The result has been presented to show that the trends for the subseries are different. Still, the detected trends of S1 and S2 are linear (because Sen’s procedure provides only linear trends), so they cannot capture the entire complexity of the series variation. The result shows a different behavior for S1 and S2 (different slopes of the trend), emphasizing the impact of the dam's inception on the river flow. The fact the null hypothesis was not rejected for S signifies that when putting together S1 and S2, the series pattern will not appear to be well described by a linear trend with a significant slope. A more sophisticated approach should be used, as is done in the following stages.

The information was added to the manuscript.

Line 318, Why only S and S2 are used in HWMDM?

Only S and S2 are used in HWMDM because the goal is to forecast the future behavior (after 2010) of the river flow, using the most actual values, but the series S1 is recorded from 1955 to 1983. In contrast, S and S2 are recorded from 1955 to 2010 and 1984 to 2010, respectively.

Figure 9. The range of forecasting in S and S2 are large and unbelievable results, even with the confidence levels of 80% or 95%. Specially, the discharge is smaller or much smaller zero. I cannot agree with the Holt-Winters Multiplicative Decomposition Model is good enough in this study. Furthermore, is the forecasting necessary in this study?

If I understood well, you consider that there are negative predicted values. The blue curve represents the forecast values, with no negative value. Indeed, the confidence interval is large, but it is computed using the R software (with a ready-to-use package). No, the forecast is unnecessary at this stage, so we removed this part and kept it for another article where a comparison of different modeling methods will be made.

In comparison, all scale of Y-asix should be in the same range if possible, such as Figure 3.

We modified Figure 3 according to your recommendation.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors discussed the statistical approach to analyzing the river discharge to identify the impact of the construction of DAM. However, the authors claimed the nobility of this research was the introduction of the framework with statistical analysis of EMD. Several significant points need to be addressed to establish the nobility of this study -

1. The abstract needs to improve by addressing the application of this study.

2. It is necessary to discuss in the introduction why this approach or statistical method is suitable for evaluating river discharge data over the other approaches. A discussion with other available methods would be helpful to understand the choice of method selection.

3. The discussion seems a little bit incomplete; a section or paragraph is essential to compare this research finding with other studies, how it is a better or a good fit for analyzing river discharge data, and how this research finding will be helpful in this field.

4. The construction of DAM has obviously altered the river discharge pattern, so a simple statistical method is good enough to know the impact. Please write the application of this research in the conclusion so that readers can see what they can do with these findings/work.

Besides some minor comments

1. Figure 4: The flow diagram should have input and output. Please clear all the steps so the reader can understand the workflow easily.

Comments on the Quality of English Language

N/A

Author Response

Dear Reviewer,

Thank you for the time spent reviewing the article and the valuable suggestions that helped improve the manuscript. Please find the answers to your comments in red.

The abstract needs to improve by addressing the application of this study.

We modified the abstract.

It is necessary to discuss in the introduction why this approach or statistical method is suitable for evaluating river discharge data over the other approaches. A discussion with other available methods would be helpful to understand the choice of method selection.

Thank you for the suggestion. We introduced discussions. Please see the red part in the Introduction.

The discussion seems a little bit incomplete; a section or paragraph is essential to compare this research finding with other studies, how it is a better or a good fit for analyzing river discharge data, and how this research finding will be helpful in this field.

There are only two studies and one short conference presentation on the Buzau River discharge, as mentioned in the Introduction. We added discussions in the section Discussion.

The construction of DAM has obviously altered the river discharge pattern, so a simple statistical method is good enough to know the impact. Please write the application of this research in the conclusion so that readers can see what they can do with these findings/work.

Thank you for the suggestion. We followed your recommendation.

Besides some minor comments

Figure 4: The flow diagram should have input and output. Please clear all the steps so the reader can understand the workflow easily.

I modified the flowchart according to your suggestion.

Reviewer 3 Report

Comments and Suggestions for Authors

Although this is a well conducted study on a relatively important topic, there is no new scientific insight provided.

The introduction should be focused on the previous studies on the influences of Siriu Dam conducted by other methods.

Rewrite the Abstract, add more specific results.

This paper need better orientation and writing that makes the technical content clearer and enhances the appeal to the intended audience.

Update reference to the recent 10 years.

Comments on the Quality of English Language

Please carefully proofread the manuscript to minimize typographical, grammatical, and bibliographic errors.

Author Response

Dear Reviewer,

Thank you for the time spent reviewing the article and the valuable suggestions that helped improve the manuscript. Please find below, in red, the answers to your remarks.

Although this is a well conducted study on a relatively important topic, there is no new scientific insight provided. The introduction should be focused on the previous studies on the influences of Siriu Dam conducted by other methods.

There are only a few articles about the influence of Siriu Dam conducted by using IHA indicators and some statistical analysis of the trend (done by Mann-Kendall and Sen’s slope). We referred to them in the Introduction. But, since another reviewer also asked for comparisons to be put into Discussion, we also referred to them in the Discussion. I hope that you will not mind.

Rewrite the Abstract, add more specific results.

Abstract was rewritten.

This paper need better orientation and writing that makes the technical content clearer and enhances the appeal to the intended audience.

We introduced clarification, reformulated some parts, and added some explanations to the methods and results.

Update reference to the recent 10 years.

We updated the references apart from those initially introducing some methods (like the Mann-Kendall test, Multifractality, EMD, etc.).

We also double-checked the article for grammar errors and typos.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Thanks for considering my comments in order to improve the manuscript. Only one point is about Figure 4; the flow diagram must be fixed. The discussion could not be output. Would you please mention the final results or findings?

Author Response

Dear Reviewer,

Thank you for your appreciation.

We modified the diagram according to your remark.