Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. The first two paragraphs of the introduction focus on stating the background and significance of the study, and this section needs to be heavily streamlined.

2. The materials and methods section needs to be streamlined. In the case of commonly used data and methods, only a short statement and appropriate references need to be cited.

3. In the component figure in the upper right corner of Figure 1, you can add the terrain information shown.

4. Table 6 and table 8 is too long and could be considered to be streamlined or converted into a graphic form or uploaded as supplementary material.

5. The conclusion section is too long, it only needs one paragraph and it doesn't need to be subdivided.

6. The whole manuscript is too long. Authors need to be very clear about what the scientific question of this study is and what the focus of the manuscript is to illustrate. On this basis, the manuscript should be substantially reduced, and those elements that are relatively less important can be deleted or briefly stated. The entire manuscript should be limited to 20 pages or less, and if it can be reduced to 15 pages, even better.

Author Response

Comment 1: The first two paragraphs of the introduction focus on stating the background and significance of the study, and this section needs to be heavily streamlined.

Response 1: Thank you for pointing this out. We agree with this comment. Therefore, we revised the first two paragraphs of the introduction.

Comment 2: The materials and methods section needs to be streamlined. In the case of commonly used data and methods, only a short statement and appropriate references need to be cited.

Response 2: Thank you for pointing this out. We agree with this comment. Therefore, we revised the section 2.3.2.

Comment 3: In the component figure in the upper right corner of Figure 1, you can add the terrain information shown.

Response 3: Thank you for pointing this out. We agree with this comment. Therefore, we revised the Figure 1.

Comment 4. Table 6 and table 8 is too long and could be considered to be streamlined or converted into a graphic form or uploaded as supplementary material.

Response 4: Thank you for pointing this out. We agree with this comment. Therefore, table 6 and table 8 have been moved to Appendix A.

Comment 5. The conclusion section is too long, it only needs one paragraph and it doesn't need to be subdivided.

Response 5: Thank you for pointing this out. We agree with this comment. Therefore, we have revised the conclusion section.

Comment 6. The whole manuscript is too long. Authors need to be very clear about what the scientific question of this study is and what the focus of the manuscript is to illustrate. On this basis, the manuscript should be substantially reduced, and those elements that are relatively less important can be deleted or briefly stated. The entire manuscript should be limited to 20 pages or less, and if it can be reduced to 15 pages, even better.

Response 6: Thank you for pointing this out. We agree with this comment. Therefore, we made revisions to the whole manuscript.

Reviewer 2 Report

Comments and Suggestions for Authors

Attribution Analysis of Runoff Change in a Changing Environ-2 ment: A Case Study of the Dawen River Basin

 

This study developed a multi-method analysis approach to distinguish the causes of surface runoff changes (climate change and human activities) in the Dawen River Basin in Shandong Province, China. Three different approaches were integrated in the study: empirical model (double mass curve), conceptual model (Budyko-based elasticity coefficient method), and hydrological modeling (SWAT model). Data were collected from 4 hydrological stations and multiple meteorological sources for the period 1961–2019; the analysis was divided into “natural” and “human activity” periods as of 1976. The findings show that human activities accounted for 70–82% of the runoff changes. SWAT modeling was determined as the most appropriate approach, especially at the basin scale, and human effects such as land use changes, reservoir operations, and consumptive water use were analyzed separately by this model. This comprehensive method provides decision makers with a powerful tool for sustainable planning of water resources under climate change and human interventions.

 

It is a well-designed scientific study. The fact that it only applies to a specific region causes concern about generalizing the results. The image quality of the study area figure needs to be improved.

Author Response

Comment 1: Attribution Analysis of Runoff Change in a Changing Environment: A Case Study of the Dawen River Basin.This study developed a multi-method analysis approach to distinguish the causes of surface runoff changes (climate change and human activities) in the Dawen River Basin in Shandong Province, China. Three different approaches were integrated in the study: empirical model (double mass curve), conceptual model (Budyko-based elasticity coefficient method), and hydrological modeling (SWAT model). Data were collected from 4 hydrological stations and multiple meteorological sources for the period 1961–2019; the analysis was divided into “natural” and “human activity” periods as of 1976. The findings show that human activities accounted for 70–82% of the runoff changes. SWAT modeling was determined as the most appropriate approach, especially at the basin scale, and human effects such as land use changes, reservoir operations, and consumptive water use were analyzed separately by this model. This comprehensive method provides decision makers with a powerful tool for sustainable planning of water resources under climate change and human interventions. It is a well-designed scientific study. The fact that it only applies to a specific region causes concern about generalizing the results. The image quality of the study area figure needs to be improved. The first two paragraphs of the introduction focus on stating the background and significance of the study, and this section needs to be heavily streamlined.

Response 1: Thank you for pointing this out. We agree with this comment. Therefore, we have revised Figure 1.

Reviewer 3 Report

Comments and Suggestions for Authors

Summary 

In the study, the authors employed 3 different approaches: double mass curve, elasticity coefficient methods, and hydrological model (SWAT) to quantify the impacts of climate change and human activities to runoff. The authors used 1961 to 1976 as baseline and 1977-2001 as period of change for the comparison. A correlation analysis was applied to selected independent runoff driver and basin characteristic factors for random forest analysis to rank the importance of those drivers/factors. The author concluded that human activities are the dominant driver for runoff change.

Major comments 

The study is comprehensive and exhaustive. The authors employed and evaluated three different methods to examine the contribution. For the correlation analysis, they considered a number of relevant factors and drivers. The writing is generally easy to read and follow; tables and figures are also easy to interpret.  

Section 2.3.1 (3) - The authors should demonstrate the performance of the SWAT model to validate its use for the analysis. Additionally, the rationale for recalibrating the hydrological model for different time periods needs to be explained. A key question is if/how the recalibration “changes/informs” the parameters to be adapted to climate and human activity changes - so that when comparing with the natural period, the changes are not only due to input differences. Land cover data have seven time slices (1980, 1990, 2000, 2005, 2010, 2015, and 2018), it is needed to clarify how they were applied in the modeling - both in model setup and in the scenario-based analysis.

In the result analysis, especially Section 3.5,  it would be helpful not only to describe the difference in patterns among the methods but also provide discussion and explanation on why the differences were present. In addition it would be helpful to know the average flow volume from the 4 locations. As the 4 locations are not completely isolated - flows from Laiwu flows to Beiwang, and  both Dawenkou and the Beiwang accumulate to Daicunba, knowing the volume would also help interpret the results. 

Some tables (for example., Table 6 and Table 8) could be moved to supplementary information for better flow and manuscript length considerations - unless specific elements need to be highlighted. Figures could benefit from additional descriptive captions that provide more detail.

Minor Comments 

Section 2.1 Study Area - some statements about the basin could benefit from proper references. For example: “These structures reduced downstream flood volumes by approximately 60%, drastically lowered sediment loads.”

Figure 1, is Dongping reservoir shown in the map area? Also, figure caption has a typo “Daven” -> “Dawen”

Line 170, what’s the resolution of the dataset? Was any post processing in addition to “crop” was applied to the data?

Line 172, There is an issue with the dataset link. Please verify and correct it.

Line 184, the author mentioned in Line 128 that there’re “23 large and medium-sized reservoirs (mostly upstream) and over 128 100 small ones” in the basin. And the authors included 3 reservoirs in this study. Clarification needed for the focus of those three. 

Line 202, if groundwater is also considered in the study, does it affect the overall water balance calculation as the storage term changes too?

Equation (2) (3), what’s the difference between Rrec,var and Rvar and how are they calculated? The authors need to address this before the rest of the equation make sense 

Line 289-line 291, it would be helpful to demonstrate the necessity and benefits for using all 7 functions, by discussing their similarities and differences, their advantages and disadvantages, or in the result section 3.3

Line 295, “The Dawen River Basin was modeled using the Soil & Water…”

Line 302, need to specify what SWAT-CUP is

Figure 3, the simulation starts from 1961, so is there any reason the plot starts from1963 instead of 1961?

Figure 5  Label x-axis consistently with other plots would be helpful for results interpretation 

Table 9. ETCCDMI is first mentioned here, the abbreviation needs to be specified 

Figure 13. Y-axis label need to be fixed 

Author Response

Comment 1: Section 2.3.1 (3) - The authors should demonstrate the performance of the SWAT model to validate its use for the analysis. Additionally, the rationale for recalibrating the hydrological model for different time periods needs to be explained. A key question is if/how the recalibration “changes/informs” the parameters to be adapted to climate and human activity changes - so that when comparing with the natural period, the changes are not only due to input differences. Land cover data have seven time slices (1980, 1990, 2000, 2005, 2010, 2015, and 2018), it is needed to clarify how they were applied in the modeling - both in model setup and in the scenario-based analysis.

Response 1: Thank you for pointing this out. We agree with this comment. Therefore, the model's performance has been added to Appendix B.2. The model was recalibrated at different periods to establish time-segmented models, where each time-specific model operates independently with its own input database. Each time-period model incorporates land use data corresponding to its respective time segment, as detailed in Appendix A1.

Comment 2: In the result analysis, especially Section 3.5, it would be helpful not only to describe the difference in patterns among the methods but also provide discussion and explanation on why the differences were present. In addition it would be helpful to know the average flow volume from the 4 locations. As the 4 locations are not completely isolated - flows from Laiwu flows to Beiwang, and both Dawenkou and the Beiwang accumulate to Daicunba, knowing the volume would also help interpret the results.

Response 2: Thank you for pointing this out. We agree with this comment. Therefore, we have revised the Section 3.5.

Comment 3: Some tables (for example., Table 6 and Table 8) could be moved to supplementary information for better flow and manuscript length considerations - unless specific elements need to be highlighted. Figures could benefit from additional descriptive captions that provide more detail.

Response 3: Thank you for pointing this out. We agree with this comment. Therefore, some tables have been moved in Appendix A.

Comment 4:  Section 2.1 Study Area - some statements about the basin could benefit from proper references. For example: “These structures reduced downstream flood volumes by approximately 60%, drastically lowered sediment loads.”

Response 4: Thank you for pointing this out. We agree with this comment. Therefore, we have added reference [38].

Comment 5: Figure 1, is Dongping reservoir shown in the map area? Also, figure caption has a typo “Daven” -> “Dawen”

Response 5: Dongping reservoir is not shown in the map area. This reservoir is located at the outlet of the Dawen River Basin. This article does not conduct research on Dongping reservoir, so it is not shown in the figure. Also, the wrongly-written characters were corrected.

Comment 6: Line 170, what’s the resolution of the dataset? Was any post processing in addition to “crop” was applied to the data?  Line 172, There is an issue with the dataset link. Please verify and correct it.

Response 6: We have revised the question raised. Please refer to lines 154-159.

Comment 7: Line 184, the author mentioned in Line 128 that there’re “23 large and medium-sized reservoirs (mostly upstream) and over 128 100 small ones” in the basin. And the authors included 3 reservoirs in this study. Clarification needed for the focus of those three.

Response 7: We have revised the question raised. Please refer to lines 169-170.

Comment 8: Line 202, if groundwater is also considered in the study, does it affect the overall water balance calculation as the storage term changes too?

Response 8: We have merely categorized the water sources for abstraction activities into surface water and groundwater, which does not affect the overall water balance calculation as the storage term changes too.

Comment 9: Equation (2) (3), what’s the difference between Rrec,var and Rvar and how are they calculated? The authors need to address this before the rest of the equation make sense

Response 9: R_var denotes the observed runoff during the human activity period,

is directly computed using Equation (2).

Comment 10: Line 289-line 291, it would be helpful to demonstrate the necessity and benefits for using all 7 functions, by discussing their similarities and differences, their advantages and disadvantages, or in the result section 3.3

Response 10: We have revised the question raised. Please refer to lines 275-277.

Comment 11: Line 295, “The Dawen River Basin was modeled using the Soil & Water…” Comment 12: Line 302, need to specify what SWAT-CUP is

Response 11: We have revised the question raised. Please refer to line 281 and lines 289-292.

Comment 12: Figure 3, the simulation starts from 1961, so is there any reason the plot starts from1963 instead of 1961?

Response 12: The period 1961-1962 served as the model warm-up period.

Comment 13:  Figure 5 Label x-axis consistently with other plots would be helpful for results interpretation; Table 9. ETCCDMI is first mentioned here, the abbreviation needs to be specified

Response 13: We have revised the Figure 5 and Table 9.

Comment 14: Figure 13. Y-axis label need to be fixed [1]

Response 14: We have revised the Figure 13 and Figure 16.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors I've checked the entire manuscript. After revisions by the authors, my concerns have been addressed and I consider this version acceptable for publication