Selection of Potential Sites for Promoting Small-Scale Irrigation across Mali Using Remote Sensing and GIS

Round 1

Reviewer 1 Report (Previous Reviewer 1)

Impressions:

The authors made significant changes to the revised manuscript. The methods and results now look more attractive and scientific to audiences. However, there is still a lot of space to be improved to make this paper more precise and scientifically.

 

Line-by-line comments:

Line 25: Please revise the sentence “…potential), soil and climate…” as “…potential), soil, climate…”

Line 111- 120: Since you mentioned and compared the regional effects in table 5 and figure 10, if you can only overlay those region boundaries in Figure 1 (and also Figure 3-8), that would make much more sense and clear of your results and discussions. And if possible, discussing the differences among the districts or the relationship between ecological zones and districts here would be wonderful for audiences to understand why you conclude your results and discussions by district instead of the ecological zones.

Figure 1: Please move figure 1(a) to the upper-left corner and switch figure1(c) to the lower-left corner. Also, modify the description of figure1(c) as “shape of Africa with Mali borders in red.” If possible, you can combine all three sub-figures into a map: overlay (a) and (b) together without the region and district name, which might not be significant to this study; use the original figure1(c) as the overview map in the corner. If possible, add some significant landmarks such as the national capital on the main map. Please see the attached figure as an example.

Figure 2: I don’t want to be picky on the flow chart symbols and linkage. However, please at least use clear symbols and connections among all the objects. It looks clear to separate satellite data from raw data in the data source section; however, satellite data could also be one of the raw data. You might end up needing to define what is your raw data in your main text or figure caption! Please refer to figure 4 on this paper as an example: https://link.springer.com/article/10.1007/s10064-017-1135-z

Line 159: “eight quantiles” might not be the correct word to describe how you rendered your data. And also, the classification might not be useful since you eventually need to assign numbers into 5 “priority score” levels. There is no way to classify your data into 8 levels here and then transfer it into 5 levels later. Please see the below comments for details.

Lin 150-164: the classification of “Accessibility to surface water” is still questionable. It looks like the classification you used just follows the default “Natural Breaks (Jenks)” classification method into 9 levels (not the 8 described in the main text) without any solid scientific evidence. The optimal classification methods for this topic are better based on known information. For example, the distance of irrigation limitation or cost-effectiveness of irrigation water acquisition can be the base knowledge to assign each class or priority score.

Figure 3(a) and Figure 8(a): since your data are continuous, you might want to re-draw your figures like figure 7(a) to reduce the confusion about the classification/"quantiles" (might not be the correct word) of your source data to the 5-level priority score. And also, in table 1, fix the classifications of "Accessibility to surface water" and "slope" to match the priority score. For example, use slope < 2% as priority score is "Very high", 2% - 4% is "High" and so on.

Line 224: please don’t use “shapefile” here directly. Not all audiences understand what “shapefile” is. Instead, using the “GIS dataset” or simply “information.”

Line 227: the correct resource link is better described as a formal citation with the resource URL and last access date.  BTW, correct URL should be https://www2.bgs.ac.uk/africagroundwateratlas/

Line 229: here, you can use “ESRI shapefile format” or simply delete these redundant terms.

Table 1: please add a column as "resolution" and more resolution notations into this column instead of after the "Theme" name. Merged the “accessibility to surface water” and “slope” into five classes described above.

Line 271: You might need to cite and add the version for all the software you used across the main text. For example, put the version of QGIS and R software your use with appropriate copyright information. Please refer to this link for details: https://qgis.org/en/site/getinvolved/faq/index.html#how-to-cite-qgis

Line 268-Lin 275: You can divide your rainfall range based on whatever evidence you have into 5 different categories. However, you need to show why the average rainfall larger than 800 mm is highly suitable. There is a citation in table 1 but not here. And also, if this citation supports the reason of 800mm as the cut-off, please use one or two sentences here to describe the reasons. It would be very helpful for audiences to understand your points, and also no need to jump back and forth between your paper and references.

Line 281-287: similar to the rainfall section, authors need to cite appropriately in this section. Also, if possible, please use one or two sentences to describe the rationale behind the classifications.

Line 293: What does “SSI” stand for? Please spell out the “SSI” the first time you use this alias in the main text.

Line 295-298: a single, long sentence that will be hard to read. Think about breaking it down.

Line 299: missing several periods at the end of sentences. Please put them back.

Line 300-303: inconsistency between “i)” and “secondly”. Please choose one style for all.

 

Citation 28-36: Please check that each link works and follow the formal citation format to add the last access date.

Comments for author File: Comments.zip

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report (New Reviewer)

The article is well presented although the concept is not novel. It is, however, good information for food security in Mali.

Normal approaches have been followed.

1)      This is a not a novel research area. The paper’s contribution is in providing a method for identifying suitable areas for crop production. Hence, this paper is important for sustainable food production planning as well as expansion of areas under crop production.  

2)      Yes, the paper is relevant because if provides a platform for agricultural development across much of sub-Saharan Africa, which is mainly constrained by lack of knowledge around which sites are suitable for sustainably expanding irrigable lands (i.e. new areas to invest) as well as absence of dataset and approaches to follow.

3)      Concerning the addition to existing publications on related topics, this paper on adds or clarifies which data sets and approaches are plausible to address this challenge.

4)      This study aimed to identify the most suitable sites for promoting small-scale irrigation in Mali based on environmental and land use/land cover criteria. The paper is simple, straight forward and well written. The paper correctly identifies areas (and their sizes) where expansion can take place. The study identifies high, moderate, and low potential areas where crop production is possible. The results and conclusions are consistent with the arguments presented as well as in line with the study aim.

I hope this address your concerns. This is not novel science but is relevant science.

 

 

Best wishes

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report (Previous Reviewer 1)

The Authors have fully responded to my previous questions and made several significant changes to this paper. However, there are still some minor questions before it can be accepted for publication.

Figure 8: the subfigure(a) seems in a mono-color compared to its legend. Also, the slope percentage scale might not fit your map. If you are using ArcGIS, you can set your symbology statistics in "DRA (Dynamic Range Adjustment)" with the stretch type as either "Standard Deviation" or "Percent Clip" to make a better visual effect (see attached PDF).

Comments for author File: Comments.pdf

Author Response

C0: The Authors have fully responded to my previous questions and made several significant changes to this paper. However, there are still some minor questions before it can be accepted for publication.

R0: we are very thankful for the reviewer time and helpful suggestions that helped us to greatly improve the manuscript. 

C1: Figure 8: the subfigure(a) seems in a mono-color compared to its legend. Also, the slope percentage scale might not fit your map. If you are using ArcGIS, you can set your symbology statistics in "DRA (Dynamic Range Adjustment)" with the stretch type as either "Standard Deviation" or "Percent Clip" to make a better visual effect (see attached PDF).

R1: We agree with the reviewer on this. Subfigure 8a is revised as suggested by the reviewer using the standard deviation method. Now the scale better matches the map. 

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

Comments for author File: Comments.pdf

Reviewer 2 Report

On a scale of a whole country, the GIS-based approach should be better addressed and all thematic layers better represented especially those related to environmental and geological factors