Assessment of Groundwater Trends in Bhopal, Madhya Pradesh: A Statistical Approach
Round 1
Reviewer 1 Report
Manuscript ID sustainability-2438070
Abstract
· In the abstract section, please specify the sources from which the groundwater quality data has been collected.
· Please mention the reasons for the decreasing trend in parameters such as SO42-, Ca2+, HCO3-, NO3-, and F-.
· Additionally, please provide information on the health effects in the region resulting from the analysis of the various parameters
Introduction
· Page number 2, line number 59-61: please add suitable references.
· Page number 2, last paragraph of Introduction section: Please elaborate on the research gap, novelty, and significance of the study.
· Page number 3, section 1.1.1: Please indicate whether the groundwater is utilized without undergoing any treatment.
Methods and materials:
Drinking suitability
· Page 4, line number 112: Please provide the updated citation for the latest WHO report and make the necessary revisions to the desirable and maximum allowable limits in Table 1 accordingly.
· Please also provide the year of publication of CGWB in the caption of Table 2.
Results and Discussion
· Please provide suitable references for section 3.1.1. and check the units of EC in line number 201.
· Section 3.1.2: The authors have stated that all 23 wells in Bhopal had fluoride levels below 1 mg/L, suggesting the need for additional fluoride for dental health. However, how can this recommendation be made without considering the daily water intake and body weights of different age groups?
· Section 3.1.3: Please explain how anthropogenic activities are responsible for the high nitrate levels observed at the two sampling sites, while the remaining 21 sites show no significant impact. Additionally, please provide suitable references to support this explanation.
To improve the “Introduction” “Materials and Methods”, and “Results and Discussion” sections, the authors can read and cite the following papers:
I. Fluoride contamination in drinking water and associated health risk assessment in the Malwa Belt of Punjab, India
II. Risk Assessment of Metals from Groundwater in Northeast Rajasthan.
III. Toxicological risk and age-dependent radiation dose assessment of uranium in drinking water in southwest-central districts of Haryana State, India
IV. Carcinogenic and Non-carcinogenic Risk Assessment of Metals in Groundwater via Ingestion and Dermal Absorption Pathways for Children and Adults in Malwa Region of Punjab
Author Response
Responses have been given in attached word file.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors present a trend analysis of the time series (22 years) of some groundwater parameters sampled in the Bhopal region of India. Although the approach used is not particularly innovative: Mann-Kendall, Modified Mann-Kendall and Theil-Sen slope are classical methods used for this type of study, the topic may be of some interest to the journal. Unfortunately, the paper suffers from several problems that make it unpublishable in its current form.
Some corrections and suggestions:
Row 25: in the abstract, I do not think this sentence is necessary.
Rows 28-61: in the introduction each sentence is supported by a single bibliographic citation, in addition to local authors, given the importance of the topics introduced, it is necessary to expand the supporting literature. A review of the international bibliography is lacking.
Rows 44-48: these two sentences are unrelated. What does the reference to numerical modeling have to do with trend analysis, how do these topics relate to each other?
Rows 59-61: this sentence should be supported by appropriate bibliographic reference.
Rows 76-94: the article is about groundwater and this is the only sentence that describes its characteristics. It is necessary to include a paragraph describing in detail the hydrogeological characteristics of the study area.
Rows 97-99: again, it is necessary to specify the characteristics of the groundwater sampling points: location (in table and map), type (well, piezometer, spring, etc.), depth of filtered section (for wells and piezometers), type of aquifer affected by the sampling.
Rows 102-103: this description of sampling points is missing.
Row 104: specify what the method consists of, or add an appropriate citation that allows verification of the methodology through the bibliography.
Rows 109-110: why only use the most recent data, it would have been interesting to check their evolution in space and time? Perhaps using the oldest dataset, an intermediate dataset, and the most recent dataset.
Rows 113-114: what did this analysis consist of? A mapping through ArcGIS? Please clarify.
Rows 133-134: Z is the MMK test statistic, not both, please clarify.
Rows 150-151: provide appropriate references to support this statement.
Rows 173-174: what this technique consists of, clarify or add a bibliographic reference that allows the reader to understand what it is about.
Rows 174-180: this whole part is a little confusing. What are you referring to? Isn't the MMK explained above? Rewrite and try to explain better.
Rows 194-296: the description of all parameters in Drinking Suitability section is too long, it would be necessary to merge everything into one section, trying to include only the information useful for the purpose of the article. In addition, it would be interesting to have maps showing the distribution of values for each parameter. All this would make the article clearer and more readable.
Rows 201-203: Table 2 shows 18 sampling points, here it is 16+7= 23 points, where do the missing 5 come from? Please clarify.
Row 204: this is the hydrochemical facies, it doesn't have much to do with electrical conductivity.
Rows 218-219: what is the depth of the wells in question? From which aquifer are they fed? These would be items to be clarified in the section on the hydrogeology of the study area.
Row 238: what does it mean? Why likely? Magnesium concentrations are shown in Table 2 for 18 points and are described in the following section.
Rows 266-267: add reference, please.
Row 275: what and where is this point?
Row 283 end of the text: in the first part of the article, the authors use the citation style required by the journal, while from here on the authors' surnames and the year are used. Citation style should be consistent throughout the text.
Row 296: above states that the concentration of chlorides and sulfates is within the limits for drinking water, while here it says that high concentrations of the same elements make the water unfit for irrigation. In my opinion, this is a contradiction; should irrigation water contain less chlorides and sulfates than water for human consumption?
Row 299: but isn't S the Mann-Kendall test statistic? What does it have to do with the Teil-Sen slope?
Row 300: isn't Z the modified Mann-Kendall test statistic?
Rows 301-302: I think there is some confusion in this section. What statistics are used? S for MK or Z for MMK?
Rows 317-319: above it mentions 7 stations (lines 102-103), while here the results of only 6 points are given? How many stations are being analyzed?
Rows319-321: there are 12 parameters listed here, but only 9 in the figures? Where are the 3 missing?
Table 3: in the Materials and Methods section for MK text, the S statistic is described and not the Z statistic, please clarify.
Rows 334-335: if the trend is not statistically significant, why is it shown in the figure? More importantly, how are the maps in Figures 5 and 6 constructed? Are they interpolations of scores? By what method?
Figure 5 and Figure 6: Figures 5 and 6 are illegible without the sampling points represented by a symbol and a label or identification code.
Rows 358-379: this is not a discussion of the results, but a general description of the problems in the study area. I think the authors should try to write a real discussion.
Rows 360-361: this sentence should have been introduced first with a description of the hydrogeological settings of the study site
Minor suggestions are reported in the attached pdf.
Comments for author File: Comments.pdf
Author Response
Responses have been given in attached word file.
Author Response File: Author Response.pdf
Reviewer 3 Report
The manuscript "Assessment of Groundwater Trends in Bhopal, Madhya Pradesh: A Statistical Approach", as presented, appears to be more of a report summarizing the values obtained from various locations, rather than providing a substantial scientific discussion or discovery. Although statistical tools such as the Mann-Kendall test and the Modified Mann-Kendall test are used, the interpretations primarily focus on the description of trends without delving into the causes or implications of these trends.
For instance, the finding that "For Calcium two stations gave positive results for the MK and MMK test in which Bilkhiria gave a decreasing trend and Islamnagar gave an increasing trend with Sen’s slope of -8.374 mg/L/year and 5.145 mg/L/year respectively" raises interesting questions about why these differences are occurring, which are not explored in the manuscript. Similarly, the analysis of various other parameters such as sodium, sulfate, nitrate, bicarbonate, fluoride, and total hardness show increasing or decreasing trends across different locations, yet the reasons behind these trends, and their potential environmental and health implications, are not discussed. These are crucial aspects that could significantly enhance the scientific value of this study. Furthermore, the study's conclusion that the state experienced an increase in pollution due to the strong influence of anthropogenic factors from industrial and domestic activities, and the aquifer properties of the area, is stated without a detailed discussion or evidence supporting these claims. The Sustainability journal typically looks for studies that not only report empirical findings but also contribute to new understandings, theoretical developments, or practical applications related to sustainability. While the use of statistical tools is commendable, the manuscript could benefit from a more in-depth exploration and discussion of the reasons behind the observed trends, as well as their implications for ground water management and sustainability.The authors are recommended to revise the manuscript to provide a deeper and scientifically new discussion that goes beyond mere reporting of the results. This might include exploring the potential causes of the observed trends, discussing their implications, and suggesting possible mitigation measures or policy recommendations. This would significantly enhance the manuscript's contribution to the field of sustainability.
Author Response
Responses have been given in attached word file.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The effort of the authors to improve the article according to the suggestions made is appreciable, however, I believe that unfortunately the article is not publishable in the Sustainability Journal.
Despite the suggestions, the part about the hydrogeological settings of the area is still very lacking, and besides that, I find no reason for innovation. The authors apply two well-known and widely used and verified trend analysis techniques to groundwater concentration data from the Bhopal region of India. The result is a paper of local interest, but hardly publishable in an international journal.
Author Response
Attached in word file
Author Response File: Author Response.pdf
Reviewer 3 Report
The authors have made an attempt in the revised version to elaborate on the observed trends and provide plausible explanations. However, further improvements are still needed to enhance the clarity and effectiveness of these explanations. The writing in the manuscript still requires improvement, as there are noticeable typos and issues with the structure of the language. Careful attention should be given to proofreading and eliminating these errors. Additionally, refining the language structuring will greatly enhance the overall readability and cohesiveness of the manuscript.
The writing in the manuscript still requires improvement, as there are noticeable typos and issues with the structure of the language. Careful attention should be given to proofreading and eliminating these errors. Additionally, refining the language structuring will greatly enhance the overall readability and cohesiveness of the manuscript
Author Response
Resolutions of comments attached in word file.
Author Response File: Author Response.pdf
