Assessing Climate Change Impact on Soil Salinity Dynamics between 1987–2017 in Arid Landscape Using Landsat TM, ETM+ and OLI Data

Round 1

Reviewer 1 Report

Sea water must be masked as absence of salinity is not true in sea water.

Author Response

Dear reviewer, many thanks for your time and contribution; we appreciate your comments and corrections to improve the quality of this paper.

Reviewer 2 Report

Some parts of the manuscript are extremely well written, eg. certain parts of the Results and Discussion, but in most other places, the key information is either lost within the description or completely missing. I feel that if the researchers were to identify the key information and noise, highlight the key components, point out the importance and novelty of the research in a succinct manner, and take out 'unnecessary' information/images/tables [what is termed unnecessary are the information that does not harm the manuscript for being removed and at the same time, does not add special value by being kept there], it will be interesting to the reader. At present, the reader has to do a lot of work to try to understand the presented research. 

Suggestion for the title: Assessing Climate Change Impact on Soil Salinity Dynamics Between 1987-2017 Using Landsat TM, ETM+ and OLI Data: Arid Landscape of Kuwait

Title has to be both informative and attractive but can not miss key words

 

Abstract:

Too much background information. Focus on what is most important and highlight your findings - numbers - clearly 

 

Keywords:

Select specific words that best describe your own work. Look at your objectives and title to identify the most appropriate ones

 

Introduction:

Lines 47 - 95 - lots of background information. Are they really necessary? What will be lost if you were to condense these lines?

Related research or the current status of knowledge is almost non-existent, but the work that is cited in 96 - 113 are interesting, if only you would discuss about them. You need to point out the gap in existing knowledge to justify your work. [check the language under this section]

The objectives of the research are lost within too much text. Filter it out and show the reader the novelty of the work being presented. Make the objectives standout in that paragraph, and point out what is special about your work, and the knowledge contribution.

 

Materials and Methods:

Section 2.2 - how many samples were taken for each class? Was the number approximately equal? From Figure 6 it looks as if ~50% of the samples are from the extreme class. How does that impact the model evaluation?

Section 2.3 - information on the satellite is interesting, but within the context of your work, what is the importance?

Figure 4 - seems redundant

Sections 2.4, 2.5, 2.6, and 2.7 - too much background information. Filter the key points and keep them.

 

Results Analysis and Discussion:

Section 3.1 - visual analysis - lines 443-506 - can all this information be derived visually?

Figure 6: plot as a square rather than as a rectangle. Have all 100 samples been plotted here?

Sections 3.1, 3.2, 3.3, and 3.4 - too much information. Filter the key points and keep them.

 

Conclusions:

Remind the objectives and state how well they have been achieved. Point out significant findings etc as well. Take out the clutter and keep it short and to the point.

Author Response

Please, see attached fiel.

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Authors and Editor,

   Thanks for your kind invitation to review the manuscript entitled “Assessing the Climate Change Impact on Soil Salinity Dynamic During the Last 30 years (1987-2017) in the Arid Landscape Using Landsat TM, ETM+ and OLI Data” by Bannari et Al-ali.

   The article is within the scopes and subject areas of the journal, namely: a) Change detection, b) Image processing and pattern recognition, c) Remote sensing applications.

   This paper examines the climate change impact on soil salinity dynamic and its changing trend in space 15 and time during the last 30 years (1987-2017) in the arid landscape; soil salinity maps are derived using a semi-empirical predictive model (SEPM) previously developed. The topic is interesting and actual considering that, mainly due to climate change and human pressure, soil salinity (as much as other land degradation processes) is increasing worldwide and new tools for monitoring and reduction are strongly required.

    I found the objectives of the research clearly stated, but regarding methodology, results and English language and style, I found several concerns to share. I divide these into major and minor comments.

 

Major comments

1. I have strong doubts about the validity of the methodological structure conceived by the authors. The authors acquired a Landsat-OLI image thereabouts simultaneously with a field survey; they preprocessed and processed the image to derive a soil salinity map using a semi- empirical predictive model (SEPM) previously developed. They used the soil samples of the field survey to validate the results of the SEPM soil salinity map. Later they acquired Landsat serial time’s datasets covering three decades (1987-2017) and applied a procedure in order to calibrate and atmospherically and spectrally normalize them. They then applied the SEPM model to these images to produce salinity maps and derive trends of salinity changes. My doubts are based on the fact that a validation of the salinity maps derived from sensors that are different from that of 2017 reference image is completely missing. Although it is undeniable that the authors made a great effort to use methodologies that normalize the images of different sensors and make them comparable, we have no evidence that the methodology used leads to reliable results. The reliability of the SEPM model in generating salinity values is demonstrated only for the 2017 image, but for the other images we only rely on a deductive and transitive relation product. Since the images of the time series were acquired with different sensors, the work, in order to have a solid scientific basis, would have to validate at least one of these via field samples.
2. Although I am not a native speaker, I have found several grammatical errors in the manuscript. I proposed a correction for several of them in the minor comments section, but probably there are many others. I suggest the manuscript to be professionally edited by a native English-speaking colleague or editing service.
3. In my opinion the manuscript is too long; it is weighed down by a whole series of descriptions which are not essential for a scientific work. For example, the whole part of the description of the history of the various Landsat satellites in paragraph 2.3 can be largely reduced by keeping only essential information such as the periods of activity and the characteristics of the spectral bands. Other examples are: i) the 2.1 paragraph about study area that contains to much geomorphological descriptions; ii) paragraph 2.6: all information given in lines 395-399 and 405-408 can be avoided.
4. Kuwait areas are classified in 6 classes according to their soil salinity, but the thresholds of salt content between the classes are not given anywhere. Only table 2 indicates the chemical properties of different soil salinity classes, but it is not clear if they are average values or what, and anywhere the thresholds between classes are not given.
5. This problem is also present on images 5 and 7. It is not clear if they show salinity maps already classified in 6 discrete classes (as the text says, lines 448-449) or if they represent salinity values through a colour palette such as the legend suggests. In the first case, the discrete colors relating to each class should be indicated; in the second case, authors should indicate the unit of measurement of salinity and the extreme values. In addition, the ocean areas must be masked.
6. All graphs don’t show significance of test.
7. In paragraph 3.1 authors provide a visual interpretation of results comparing salinity map to soil characteristics. The authors should provide beside the salinity map a pedological map or consider removing the visual interpretation and evaluating the salinity map only statistically.
8. Regarding climate analysis, why the authors focus only on maximum temperatures and not on average temperatures?

 

Minor comments

1. Line 18: replace “with” with “to”
2. Line 38: correct “found to be strongly have expanded”
3. Line 49: change “threat” to “threats”
4. Line 60-63. All verbs must be corrected to third singular person
5. Line 68: change “exist” to “exists”
6. Line 87: change “require” to “requires” and “is” to “are”
7. Line 91: change “for mapping a large areas” to “for mapping large areas”
8. Line 93: change “allows” to “allow”
9. Line 102: remove “the”
10. Line 104: change “problem” to “constraints”
11. Line 122: change “in the arid land” to “arid environment”
12. Lines 126-142. If you say that methodology involves 5 steps, then when you explain them you must number them.
13. Line 150. Remove “the”.
14. Line 176. Change “are consisted” to “consist”.
15. Line 190: change “grind” to “ground”.
16. Line 304. Change “Sun” to “sun”.
17. Line 353. Change “domains” to “domain”.
18. Line 366. Remove “a”.
19. Line 376-385. In the equation authors use “C^ste”, in the following text “C^st”.
20. Line 483. Remove “it” and change “group” to “groups”.
21. Line 487. Change “find” to “found”.
22. Figure 6. Add legend indicating what the two lines represent.
23. Line 535. Change “highlight” to “highlights”.
24. Line 580. Change “corroborating” to “corroborates”.
25. Line 612. Change “draught” to “drought”.
26. Line 650. Indicate the figure where precipitations are available.
27. Line 699. Change “variations” to “variation”.
28. Figure 9. Add, square R, equation of the trend line and significance.

 

 

Author Response

Please, see attached fiel

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The comments that the researchers accepted have been addressed, and what they have not, they have given reasons for not doing so. As such, I am happy with the way the manuscript reads at the moment. 

Author Response

Many thanks for your time and your contribution to improve the quality of this paper.

Reviewer 3 Report

See attached file

 

Comments for author File: Comments.pdf

Author Response

Please, see attached fiel.

Thank you for your copperation

Author Response File: Author Response.pdf