Seasonal Differences in the Hydrochemical Characteristics of Karst Wetlands and the Associated Mechanisms in Huixian, China
Round 1
Reviewer 1 Report
The paper by Ba et al. reports the hydrochemical characteristics and dynamics of evolution in a Chinese karst area. They organized systematic field investigation and lab analysis, and so the dataset is valuable. Apparently, it is an interesting case study. Generally, the paper is well written. Chapter Materials and Methods contain all necessary information. The authors presented the results in a clear and understandable manner. Before considering for publication, the authors should pay attention to the following comments and suggestions, which might be of concerns for the potential readers:
The paper should have line numbers to help the editor and reviewers go to the words/sentences.
In the abstract,
Findings obtained from stable isotopes should be mentioned.
Use subscript for "SO4".
Remove the "in summary" sentence in the abstract and highlight the theoretical and practical values of your study.
The introduction is too short! This section should not only contain the importance of the study. The background should be more detailed. why do you conduct this study? why you choose Huixian as study area? The critical geographical variation caused by human activities and climate change is suggested to be quantified. Also, please provide some recent research progress about the hydrochemcial evolution in Chinese wetland. The following papers may be helpful and are suggested to be referred to:
- Mai, Y., Zhao, X. & Huang, G. Temporal and spatial variability of water quality in an urban wetland and the effects of season and rainfall: a case study in the Daguan Wetland, China. Environ Monit Assess 194, 347 (2022). https://doi.org/10.1007/s10661-022-09995-6
- Chengcheng Xia, Guodong Liu, Hongye Xia, Fangting Jiang, Yuchuan Meng. Influence of saline intrusion on the wetland ecosystem revealed by isotopic and hydrochemical indicators in the Yellow River Delta, China, Ecological Indicators, Volume 133, 2021, 108422, https://doi.org/10.1016/j.ecolind.2021.108422.
- Ban, J.; Ling, B.; Huang, W.; Liu, X.; Peng, W.; Zhang, J. Spatiotemporal Variations in Water Flow and Quality in the Sanyang Wetland, China: Implications for Environmental Restoration. Sustainability 2021, 13, 4637. https://doi.org/10.3390/su13094637
"knowledge on the hydrochemical characteristics of groundwater and its evolution remains limited". I don't agree with this opinion, studies related to hydrogeochemistry have been conducted widely across the world.
In Methods and materials,
What is "17D" isotope?
" 35, four, 24, and 50 samples": please use uniform number format.
Wrong spelling of "in order to" in page 4.
In Results and discussions,
For the comparison between ion concentrations, I think meq/L is better than mg/L.
"The relationship between main anion and cation concentrations were similar between surface river water and groundwater": This statement is not accurate, as some of them differ greatly, for example, SO4.
Page 8: "which all exceeded the standard limits of Class III groundwater", who is the publisher of this standard? Please add a reference here.
Figure 5: please provide results of significance test for these linear regressions. I don't think the relationship in blue hole is "good" from visual estimate, and the scatters of subterranean stream is too few.
Page 14: "global meteoric water line" instead of "global precipitation line".
The scatters used for setting up the D-O relation are too few. It has been stated "Fig 1 shows the distribution of sample sites for 17D and 18O isotope samples". Lots of sampling points for blue holes are plotted in Fig. 1, but only 2 scatters are used in Fig. 12, why?
What hydrological processes can be indicated by the isotope tracers should be analysed more deeply.
Author Response
Point 1: In the abstract,Findings obtained from stable isotopes should be mentioned.
Response 1: The fingding of stable isotopes has been added in the abstract.
Point 2: Use subscript for "SO4"
Response 2: The manuscript has been revised.
Point 3: Remove the "in summary" sentence in the abstract and highlight the theoretical and practical values of your study.
The introduction is too short! This section should not only contain the importance of the study. The background should be more detailed. why do you conduct this study? why you choose Huixian as study area? The critical geographical variation caused by human activities and climate change is suggested to be quantified. Also, please provide some recent research progress about the hydrochemcial evolution in Chinese wetland. The following papers may be helpful and are suggested to be referred to 1,2,3:
Response 3: According to the corresponding literature, the manuscript has been modified and supplemented.
Point 4: In Methods and materials,What is "17D" isotope? " 35, four, 24, and 50 samples": please use uniform number format.
Wrong spelling of "in order to" in page 4.
Response 4: "17D" has been changed to "2H""." 35, four, 24, and 50 samples" has been changed to " 35, 4, 24, and 50 samples": Wrong spelling of "in order to" in page 4 has been modified.
Point 5: In Results and discussions,For the comparison between ion concentrations, I think meq/L is better than mg/L.
Response 5: Thank you for your comment. However, in order to facilitate a unified understanding of ion changes and the over standard situation of relative standard values, we finally decided to use the customary mg/L unit.
Point 6: "The relationship between main anion and cation concentrations were similar between surface river water and groundwater": This statement is not accurate, as some of them differ greatly, for example, SO4.
Response 6: Thank you very much. We have made a description in the revision.
Point 7: Page 7: "which all exceeded the standard limits of Class III groundwater", who is the publisher of this standard? Please add a reference here.
Response 7: Corresponding references have been supplemented, see reference [47].
- General Administration of Quality Supervision, Inspection and Quarantine of the P.R. China, Standardization Administration of the P.R. China. GB/T14848—2017 Standard for Groundwater Quality. 2017.
Point 8: Figure 5: please provide results of significance test for these linear regressions. I don't think the relationship in blue hole is "good" from visual estimate, and the scatters of subterranean stream is too few.
Response 8: Thank you for your constructive comments. Indeed, some sampling points are relatively few. We will research more samples in the future sampling process. The significance test results of linear regression are as follows :Blue hole NO3=0.03TDS + 9.61, R2=0.43; Subterranean stream NO3=0.137TDS - 22.03, R2=0.82; surface water NO3=0.048TDS - 22.97, R2=0.52; Well water NO3=0.11TDS - 8.395, R2=0.61.
Point 9:Page 14: "global meteoric water line" instead of "global precipitation line".
Response 8: The manuscript has been revised.
Point 10: The scatters used for setting up the D-O relation are too few. It has been stated "Fig 1 shows the distribution of sample sites for 17D and 18O isotope samples". Lots of sampling points for blue holes are plotted in Fig. 1, but only 2 scatters are used in Fig. 12, why?
Response 10: Figure 1 shows the distribution of hydrochemistry full analysis samples and isotope analysis samples. There are relatively few isotope test samples, and not all full analysis samples have been tested and analyzed. Combined with the recent sampling analysis and test results, three groups of blue hole water have been added in Table 2.
Point 11: What hydrological processes can be indicated by the isotope tracers should be analysed more deeply.
Response 11: The manuscript has supplemented and improved the isotope analysis process.
We appreciate for Editors/Reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper is well written and interesting to read, it is written cleraly in scientific sense with interesting topic and it may be published in Water. The only suggestion for further investigation is involving the turbidity data as important data for water quality analysis with reference to rainfall data (time series analysis). The proper description of the whole system is the goal of the scientific investigations.
Author Response
We appreciate for Reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions.
Round 2
Reviewer 1 Report
The authors have given proper responses to all my comments. I am happy to recommend this paper to be published in WATER.
