Assessment of Surface Water Availability under Climate Change Using Coupled SWAT-WEAP in Hongshui River Basin, China
Round 1
Reviewer 1 Report
Comments for authors
The work presented shows the interest of the authors in an important issue worldwide, due to the implications of climate change (RCP: 2.6, 4.5 and 8.5) and anthropic activities on the availability and demand of future water resources for the 4 sectors analyzed in the Hongshui River Basin, China. The manuscript presents interesting application ideas for the combined SWAT-WEAP model. For which, I congratulate the authors. However, they must be able to respond to the suggestions and recommendations made to the manuscript so that their work can be considered for a possible publication in this scientific journal.
General comments and general suggestions.
The Introduction and discussion sections are very long. Less is more. It is recommended to highlight and discuss the most important ideas of the work.
Sub-section 2.4. Model calibration and validation. Lines 218 to 233. The SWAT model was used to generate input values for the WEAP model. The values shown in figures (3a and 3b) overestimate the simulation of the SWAT model for different months. These variations in values had some effect on the results. Explain.
Line 256 (Table 2: Performance criteria of monthly simulated and observed streamflow over Qianjiang hydrological station). To what can be attributed the gradient observed between the calibration values (-86) vs validation (9.3) with PBIAS for the WEAP model.
Line 257 table 3 Performance criteria of monthly simulated and observed streamflow over Tianer hydrological station. Could the authors explain the gradient between calibrated vs observed values for SWAT and WEAP with PBIAS? Also explain why low values are obtained with NSE for WEAP. The gradients had some effect on the research results.
Line 276. Why did the authors use assumptions of population growth, land use and consumption, since these elements are important, due to the degree of pressure they exert on the supply and demand of water?
It is suggested that the results of the different scenarios (RCP 2.6, 8.5 and 4.5) (Figures 11, 12 and 13) be homologated.
Particular comments and general suggestions.
Line 19. What is the sixth scenario? Only three scenarios (2.6, 4.5 and 8.5) for four sectors are analyzed in the manuscript. Explain.
Lines 56 to 84. The ideas are important and allow to strengthen the theoretical framework of the research, however, I consider it necessary to reduce the text.
Line 151. Authors are suggested to improve image quality. In the subsection of the study area, elements (rivers and dams) that are not shown in figure 1 are mentioned. It is recommended to add on the map the elements that are mentioned in the text, if they are relevant for the research, otherwise, it is not necessary to mention them in detail in the manuscript.
Line 143. Could the authors explain the meaning of “with west-to-east variations” in the paragraph.
Line 181. The soil data and Land use websites indicated in table 1 are disabled.
Line 163. Website disabled
Lines 265 to 267. What periods were used for the analysis? The rate of population changes and deforestation were considered, as well as the projections for new industrial constructions.
Line 275. Current or actual.
Line 276. Why did the authors decide to use assumptions?
Line 283. Figure 4 is the result of the investigation or corresponds to subsection 2.5 (scenario development). The information displayed is important, but it is unclear how the figure relates to the text.
Lines 298 to 303. The calculations made for domestic, forestry and industrial demand are correct. It is recommended to verify the amounts on lines 287 to 294. This could affect the analysis performed on lines 316 to 329.
Line 313. It is suggested to use screens to represent the services in figure 7. The current colors are not adequate.
Line 319. Figure 6 shows a comparison of the observed and modeled demand for water for the year 2010, and not projections 2010-2050, as described in the text.
Line 353. It is recommended to ungroup the sectors (Forests, Animal husbandry and Livestock) in table 5, to improve the analysis and interpretation of results according to the text.
Lines 380 to 381. The idea expressed by the authors is timely, I consider it important to improve their writing for a better understanding.
Line 381 - 382. The text does not explain Figure 4. Verify.
Lines 375 to 387. Subsection 3.6 (Low Climate change extended scenario (RCP-2.6). It is recommended to explain in detail the representation of results in figure 11 (line 389), since it may indicate that the climate change scenario with low emission radiative forcing RCP 2.6 is expressed in units of MCM.
Line 400. It is recommended that the order of the figures (12) correspond with the text. What is the meaning of FAH?
Line 425. I believe that this figure allows us to analyze and interpret the ideas in the text more than figures 11, 12 and 13
Lines 436 to 438. The idea is interesting. It is recommended to enlarge in greater detail. The text refers to figure 15, but two are shown, what is the figure?
Lines 440 to 442. The strategies mentioned by the authors are not reflected in the manuscript.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
This paper examined the water demand and supply in the future using two models and climatic data, which was very interesting and looks useful but requires some minor modifications.
L 163. What variables were extracted from the soil map for use in this experiment?
L 177. Can you add more explanations about the observed dataset from CCT? Are they in-situ observations? It is very important whether they are in-situ observations or not.
L 219. How did you calibrate the models? Please add some explanations about the procedures and techniques for the calibrations in more detail.
L 221. Can you provide some photos of Qianjiang and Tianr hydrological stations?
L 349. Some more explanations will be necessary for the deforestation scenario. How and how much would it be deforested?
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
The topic is very interesting as also methodology, but the language is very poor and difficult to understand. A massive and radical revision of the text is recommended.
Here there are also some specific comments:
Line 20: "The simulated results show that precipitation and streamflow would likely observe slightly increase" in which circumstance? explain it better.
Line 66: percentage relation with temperature is not clear, firstly you say that it increases then that it goes from 5.4 to 4.5; explain it better.
line 141-144: in the basin description, as it is very huge, you should show pluviometric and thermometric station location from which you took informations about temperature and precipitation, as well as detailed tables with those information stations by station and year by year (recommended also month by month) and with the time period records.
line 148: "Significant changes have occurred in the natural cycle of the river due to climate change and to anthropogenic activities" if you talk about them, you should explain them better with examples, locations, and periods.
figure 1: can you increase the resolution of the picture? some small words are not readable
line 158: a figure with DEM of the basin or an hypsometric curve of the basin is recommended
line 168: you should provide at least a table with a list of the station and specific information and a figure with their position on the map
table 2 and 3: performance indicators show in most cases good results, however in tab 3 calibration and validation of WEAP module show lower values, you should explain in the text the reason of that (at least making some hypotheses)
figure 4: you say "rainfall" in the title of the figure and "precipitation" in the y-ax, use only one term. And insert a legend.
figure 7 and line 321-323: MCM is not the standard abbreviation for "Milion Cubic Meter". Mm3 is the right one (with the 3 as exponent of the small m)
table 4: only 1 decimal is sufficient at this scale. example: write 2178.8 instead of 2178.816
paragraph 3.3; line 342: do you add a linear increase in agriculture only in the scenario with negative population growth? why? You should explain it better or make boundary conditions of this simulation equals to the one with positive population growth, otherwise you can't plot results in the same graph.
Discussion and Conclusion sessions are not formatted with the same template.
Conclusions are too short, you say that this study will be helpful for stakeholders, explain better why.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
