Review Reports - Groundwater Quality for Irrigation Purposes in the Diass Horst System in Senegal

Round 1

Reviewer 1 Report (Previous Reviewer 1)

After reviewing the re-submitted paper, I think the authors have revised the manuscript thoroughly according to comments from me and another reviewer. Now it has been improved greatly and from my opinion, meet the requirement of the journal WATER.

I would like to recommend it to be published in the present form.

Author Response

Response to Reviewer 1

Dear Editor and Reviewers

Thank you very much for the review of our manuscript. We appreciated the reviewer comments and we want to thank them for the time spent to understand our work. We believe that the comments and suggestions greatly contributed to the improvement of our manuscript. We hope that the reviewers will be satisfied with the improvements and recommend the paper for publication.

Open Review

( ) I would not like to sign my review report
(x) I would like to sign my review report

English language and style

( ) Extensive editing of English language and style required
( ) Moderate English changes required
(x) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	(x)	( )	( )	( )
Are all the cited references relevant to the research?	(x)	( )	( )	( )
Is the research design appropriate?	(x)	( )	( )	( )
Are the methods adequately described?	(x)	( )	( )	( )
Are the results clearly presented?	( )	(x)	( )	( )
Are the conclusions supported by the results?	(x)	( )	( )	( )

Comments and Suggestions for Authors

I would like to recommend it to be published in the present form.

Submission Date

12 August 2022

Date of this review

22 Aug 2022 09:16:43

Author Response File: Author Response.docx

Reviewer 2 Report (New Reviewer)

Good article aims to evaluate the groundwater quality for agriculture in Senegal based on (39 from the Maastrichtian and 23 from the Paleocene. The manuscript is well written supported with good citations in good language style. However, I have many concerned about the figures. Therefore, I recommend accepting the manuscript for publication in Water Journal with a Major revisions.

Hereinafter, the major recommendation for the authors in the text is only a sample of the issues.

o In Line 38 use [x] for citation instead of (xx).

o Line 34 to 36 need supported citations for scaricity of rain water in Arid and semi-arid regions. Use this citation:

Eissa M., de Dreuzyb , J., Parker B., (2018) Integrative management of saltwater intrusion in poorly-constrained semiarid coastal aquifer at Ras El-Hekma, Northwestern Coast, Egypt. Groundwater for Sustainable Development, Volume 6, March 2018, Pages 57-70.

o In Figure 2, change the Hanchard for the Paleocene confined and the Paleocene unconfined Pout.

o What about if you add one more Figure for the Geological map of the study area.

o Enhance the quality of Figure 5 a and 5 b. Move legend down inside the figure and extend the graph to the right and left sides to use the empty spaces.

o I notice something important………. You did not fix the symbol for the Maastrichtian and Paleocene aquifers in all figures. For example, in figure 3., you used to filled triangle for Maastrichtian and filled circle for Paleocene aquifer, then in Figure 4, the Piper diagram, author used filled square for the Paleocene and filled triangle for Maastrichtian, then hollow circle and triangles for Figure 5, then red and blue in Figure 6. FIX SYMBOLE FOR EACH AQUIFER throughout the whole manuscript.

o In Figure 7 and Figure 8, as mentioned in the previous comment, use two different symbols for the Paleocene and the Maastrichtian aquifers, then use different colors to discriminate different classes for each aquifer.

Best Regards

Author Response

Response to Reviewer 2

Dear Editor and Reviewers

Open Review

( ) I would not like to sign my review report
(x) I would like to sign my review report

English language and style

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	(x)	( )	( )	( )
Are all the cited references relevant to the research?	(x)	( )	( )	( )
Is the research design appropriate?	(x)	( )	( )	( )
Are the methods adequately described?	(x)	( )	( )	( )
Are the results clearly presented?	(x)	( )	( )	( )
Are the conclusions supported by the results?	(x)	( )	( )	( )

Comments and Suggestions for Authors

Hereinafter, the major recommendation for the authors in the text is only a sample of the issues.

o In Line 38 use [x] for citation instead of (xx).

REPLY: Corrected as suggested.

o Line 34 to 36 need supported citations for scaricity of rain water in Arid and semi-arid regions. Use this citation:

REPLY: We thank the reviewers for the helpful reference and included it in the new version

o In Figure 2, change the Hanchard for the Paleocene confined and the Paleocene unconfined Pout.

REPLY: The Hanchard for the Paleocene unconfined Pout was changed as suggested by the reviewer to differentiate it to the Paleocene confined Pout.

o What about if you add one more Figure for the Geological map of the study area.

REPLY: We believe that figures 2 and 3 already contain enough informative to describe the geology and hydrogeology of the study area. Figure 2 shows the different geological formations in the area. The latter are shaped into different aquifer systems by the faults which are well represented in Figure 3.

o Enhance the quality of Figure 5 a and 5 b. Move legend down inside the figure and extend the graph to the right and left sides to use the empty spaces.

REPLY: Figure 5a and 5b were modified as suggested by the reviewer.

REPLY: As suggested we fixed the symbol for the Maastrichtian and Paleocene aquifers in all figures.

REPLY: Done as suggested

Best Regards

Submission Date

12 August 2022

Date of this review

02 Sep 2022 17:40:12

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report (New Reviewer)

The author(s) modify all the required comments related to the text in the manuscript file and all figures. The manuscript has been greatly modified and figures are consistent with the text. I accept the manuscript for publication in the Water J.

Regards

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

This paper reports an interesting case study focusing on the water quality in an important agricultural area.The data set is important and the findings may help improve the efficient management of local water resources. Generally, it is organized very well. I agree this paper to be published after some modification. My main concern is that the authors use different indicators to evaluate the risks of salinity and obtain different results, but how to provide a comprehensive understanding based on these results? This point hasn't been well presented in the manuscript. Based on all these analyses, which points are suitable for irrigation and which ones are not?

Specific comments are provided below:

Abstract:

It's too long. According to the journal guidance, this part is suggested to be no more than 200 words. Please only keep the most important methodologies and key findings.

Introduction:

Line 55: I think the words "demands for" are redundant, please delete them.

Line 66: what is "aggregated"?

Lines 76-78: please highlight the advantages of combined use of multiple parameters and hydrochemical characterization, which help better understand the problems mentioned above. More updated examples of applications are recommended to be referred to:

Yahong Zhou, Peiyue Li, Leilei Xue, Zihan Dong, Duo Li,
Solute geochemistry and groundwater quality for drinking and irrigation purposes: a case study in Xinle City, North China,
Geochemistry, Volume 80, Issue 4, Supplement, 2020,125609, https://doi.org/10.1016/j.chemer.2020.125609.
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.
Xu, P.; Feng, W.; Qian, H.; Zhang, Q. Hydrogeochemical Characterization and Irrigation Quality Assessment of Shallow Groundwater in the Central-Western Guanzhong Basin, China. Int. J. Environ. Res. Public Health 2019, 16, 1492. https://doi.org/10.3390/ijerph16091492

Methods and materials:

Lines 151-152: why samples were collected at only 11 boreholes in December? Are they included in the 62 collected in June or new ones? Please also make it clear in which boreholes samples are collected twice in Figure 3.

Section 2.2: please mention the processes of sample transport and storage.

Figure 1,2 & 3: please use the standard geographical coordinates of "degree minute second" for the map.

Results and discussions:

Line 233: "summarized" instead of "summarizes".

Table 1: the unit for ions should be mg/L. provide valences for cations. The superscript for HCO3 is wrong.

Lines 249-250: for the comparison between ion concentrations, the unit should be mol/L or meq/L.

Line 268: the caption is covered by the figure. Please adjust the format.

Figure 4: please distinguish the scatters from two aquifers in Piper's diagram, with different colors or symbols.

Line 285: "exploited" instead of "exploit".

LInes 354-355: These 7 ions are major ions and sources of salt for all natural waters, so I suggest to delete this sentence.

Line 361: "three" instead of "tree".

Line 412: it should be Na%-EC relation.

Reviewer 2 Report

After reading it, I think this manuscript reported only some routine assessment work. More work is needed to make it publishable. My main comments and suggestions are as follows.

“A study of” should be removed from the title to make it short.
Abstract is lengthy and should be reduced to around 250 words. There are many redundant sentences in abstract and should be removed.
In the first paragraph of Introduction, the authors mentioned some numbers. However, these numbers are derived from very old literature. Please use some latest numbers to highlight the water resources and irrigation water.
There are some language errors, such as to studies on line 77. Indexed and indices were both used in this manuscript, please use only one of them. Line 233, is summarizes should be is summarized. Please check the language carefully.
Introduction is poor, and it should be rewritten in a more international context. Otherwise, it will not interest international researchers. In addition, a literature review is needed so that the scientific or practical problems can be summarized. The problems summarized are the initiative for you to conduct the present study. Therefore, before summarizing the objectives, you should summarize the problems. Some international articles should be used in the literature review part such as https://doi.org/10.1007/s12665-018-7968-3, https://doi.org/10.1080/07900627.2018.1443059, https://doi.org/10.1007/s12665-019-8471-1, https://doi.org/10.1007/s12665-018-7456-9
Please explain why in December 2019 only 11 samples were collected while 62 were collected in June. I think it is better to keep the sampling the same. In addition, were the water samples collected from phreatic aquifer or confined aquifer? Please introduce the information in detail.
The authors used five indices to assess the irrigation water quality. However, these methods may yield different water quality grades. So how can decision makers or researchers use your assessment results? Please discuss this in the manuscript.
The authors introduced these five indices in detail. However, these 5 indices are widely used, and therefore, I think it is useless to introduce them in such great detail. Try to reduce the introduction to the 5 indices.
Table 1 is useless, because the authors provided statistical results in Tables 2 and 3. In addition, please also provide results for the data in December 2019. The data of December 2019 were not used and discussed in this study.
As water samples were collected from two different seasons, there should be comparison between the two seasons. However, I did not find any comparison. In addition, I think the discussion part is very weak. Only routine work was reported. I think this manuscript should be rewritten to include seasonal changes of groundwater quality. In addition, groundwater resources development and management should be added as a new section so that the assessment results can be readily used. Otherwise, this manuscript reported only routine irrigation water quality assessment, which is not that innovative.
There are too many figures, and the number of figures should be reduced to less than 8.