Assessing the Impacts of Migration on Land Degradation in the Savannah Region of Nigeria

Round 1

Reviewer 1 Report (Previous Reviewer 1)

Comments and Suggestions for Authors

 The manuscript seeks to assess the impact of land degradation on the Savannah Region of Nigeria. The study is very interesting, but there are many problems that the author needs to further modify and improve.

1. Is it appropriate to use only NDVI to characterize land use degradation?

2. It is suggested to add land use data transfer matrix in different periods to further characterize land use degradation.

3. There are too many paragraphs in the introduction, which need further elaboration.

4. Studying the location map, it is suggested to give a global map in order to clearly understand the location of Nigeria.

5. Figure 4 suggests further beautification.

6. As can be seen from Table 1, NDVI values are all small, and the authors need to carefully consider whether other indicators should be used to characterize land degradation.

7. The manuscript needs a native English speaker to polish it.

8. Tables 3 and 4 require further optimization.

9. The formatting of the manuscript needs to be carefully checked by the author to ensure that the formatting is accurate. For example, there are problems with the title of the conclusion.

 

Comments on the Quality of English Language

The manuscript needs a native English speaker to polish it

Author Response

Comment 1: Is it appropriate to use only NDVI to characterize land use degradation?

Response 1: NDVI and NDBI were used in tandem, to provide a more accurate picture of land degradation because of their complementary nature in detecting changes in vegetation (NDVI) and built-up areas (NDBI). This dual approach was specifically chosen to overcome the limitations of using land use/land cover analysis in the communities where long-term urbanisation had already altered the landscape.

Comment 2: It is suggested to add land use data transfer matrix in different periods to further characterize land use degradation.

Response 2: We initially considered using the land use data transfer matrix for multiple periods at the community level; however, the analysis yielded minimal results due to the extensive urban growth and land use changes that predate the availability of adequate remote sensing data (as indicated on the Google Earth images). These changes were not sufficiently captured by traditional land use/land cover analysis, so we opted for NDVI and NDBI, which offered a better view of the current state of land degradation in these locations. This has been included in our limitation of study.

Comment 3: There are too many paragraphs in the introduction, which need further elaboration.

Response 3: Thank you for the suggestion. This has been well taken care of.

Comment 4: Studying the location map, it is suggested to give a global map in order to clearly understand the location of Nigeria.

Response 4: Thank you for the suggestion. We assume that most readers are familiar with the global location of Africa, so a detailed world map is not necessary to understand Nigeria's geographical position. A world map contains a lot of information that is irrelevant to the specific localisation of Nigeria and may affect the aesthetics of the study area map.

Comment 5: Figure 4 suggests further beautification.

Response 5: Thank you for this suggestion. We have amended it and improved readability for better aesthetic viewing.

Comment 6: As can be seen from Table 1, NDVI values are all small, and the authors need to carefully consider whether other indicators should be used to characterize land degradation.

Response 6: Thank you for this comment. The low NDVI values observed in Table 1 reflect the absence of vegetation and the extensive urban growth of the migration destination hotspots which are also Savannah areas. Built-up areas typically have low NDVI values reflected in the Google Earth images. These characteristics, coupled with the limitations of available historical remote sensing data, constrained the ability of NDVI alone to fully capture the extent of degradation. In addition, these values were obtained at the peak of the dry season to minimise the effects of cloud cover which may distort the actual values. To address this, NDBI was integrated into our analysis, along with field survey data, to provide a more comprehensive understanding of the land degradation process in these highly altered environments. We have included this explanation in the limitation of our study.

Comment 7. The manuscript needs a native English speaker to polish it.

Response 7: Thank you for the suggestion. The manuscript has been proofread and polished by a native English speaker.

Comment 8. Tables 3 and 4 require further optimization.

Response 8: Thank you for pointing this out. We've addressed this by relocating them to the appendix to streamline the main body of the paper and enhance readability.

Comment 9. The formatting of the manuscript needs to be carefully checked by the author to ensure that the formatting is accurate. For example, there are problems with the title of the conclusion.

Response 9: Thank you for the suggestion. The formatting has been reviewed and adjusted appropriately.

 

Thank you for your time and effort in reviewing our manuscript.

 

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

The paper pursuit a major objective associated with the assessment of the impacts of migration on land degradation on four migration destination communities (Sabon Gari East, Sabon Gari West, Zuba and Tungamaje) located in two local government areas in Nigeria. This is an interesting paper, dealing with geospatial analysis of land degradation and field survey data collection and analysis. Thus, I recommend its publication. Good luck!

Author Response

Reviewer 2

Comment 1: The paper pursuit a major objective associated with the assessment of the impacts of migration on land degradation on four migration destination communities (Sabon Gari East, Sabon Gari West, Zuba and Tungamaje) located in two local government areas in Nigeria. This is an interesting paper, dealing with geospatial analysis of land degradation and field survey data collection and analysis. Thus, I recommend its publication. Good luck!

Response 1: Thank you very much. Your comment is highly appreciated

 

Thank you for your time and effort in reviewing our manuscript.

Author Response File: Author Response.docx

Reviewer 3 Report (New Reviewer)

Comments and Suggestions for Authors

I would like to thank the authors for a research paper that examines the environmental implications of migration, focusing on how urban expansion has driven land degradation in Nigeria's Savannah Region.  

I have read the draft with great interest. In my view, the topic merits attention, and research offers certain insightful findings (albeit somewhat expected). The proposed regional focus is particularly relevant given the increasing urbanization trends in Sub-Saharan Africa - and the already visible environmental changes that accompany them. I appreciated the motivation of the authors (beyond advancing research) to inform relevant actors and contribute to urban planning/resource management, as they make it clear in the conclusions. 

In my view, the article is well-structured, presenting a link between migration, urban expansion, and land degradation. The methodology is adequate for an assessment of the impact of migration on land degradation in four communities within two local government areas, involving focus group discussions, surveys, and spatiotemporal analysis. The findings are presented in a coherent manner, specifying that a majority of respondents perceive migration as a significant contributor to land degradation.  

I would like to offer a few suggestions for consideration.  

First, the connection between the NDVI/NDBI data and community perspectives could be more explicitly integrated into the conclusions. 

Second, the authors may want to include additional details concerning socio-economic factors driving migration (duly mentioned in the Introduction, lines 50-57), to add further depth to their conclusions.  

Overall, the article offers a solid contribution to the literature on migration and environmental sustainability; I also see its value in advancing informed policymaking and urban planning.

I wish the authors success in their future research activities, potentially expanding the geographic coverage beyond four communities, which would enhance the generalizability of their findings.

Author Response

Reviewer 3

Comment 1: First, the connection between the NDVI/NDBI data and community perspectives could be more explicitly integrated into the conclusions. 

Response 1: Thank you for the suggestion. This suggestion has been implemented. The information about the connection has been integrated into the study’s conclusion (lines 488-489).

Comment 2: Second, the authors may want to include additional details concerning socio-economic factors driving migration (duly mentioned in the Introduction, lines 50-57), to add further depth to their conclusions.  

Response 2: Thank you for your suggestion. While the primary focus of this study was on assessing the environmental impacts of migration, particularly land degradation, analysing the drivers of migration was outside the scope of this study. However, we acknowledge the importance of these factors in understanding the broader context of migration and land degradation. We plan to explore this dimension in subsequent studies.

 

Thank you for your time and effort in reviewing our manuscript.

 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report (Previous Reviewer 1)

Comments and Suggestions for Authors

The manuscript has been revised, and there are still some problems that need further improvement and revision.

1.     Overall, the innovation of the paper needs to be further clarified.

2.     The manuscript has been revised, and there are still some language problems that need further improvement and revision.

3.     Figure 4 need further embellishment.

4.     The color bar in Figure 5 needs to be unified.

5.     Figure 7 also needs further embellishment.

6.     The conclusion needs to be further summarized and condensed.

 

Comments on the Quality of English Language

The manuscript has been revised, and there are still some language problems that need further improvement and revision.

Author Response

Response to Reviewer

We would like to express our gratitude to the reviewer again for the thoughtful feedback on our manuscript, which has been instrumental in enhancing the quality of our article. We have taken each comment into careful consideration and provided our responses below.

 

Comment 1: Overall, the innovation of the paper needs to be further clarified.

Response 1: Thank you so much for the suggestion. The innovation has been clarified in the abstract (lines 20-23), introduction (lines 76-80) and methodology (lines 217-220)

Comment 2: The manuscript has been revised, and there are still some language problems that need further improvement and revision.

Response 2: Thank you for the suggestion. Efforts have been made to address this issue. The language has been revised and further improved.

Comment 3: Figure 4 need further embellishment.

Response 3: Thank you for the observation. The figure has been further embellished for better viewing

Comment 4: The color bar in Figure 5 needs to be unified.

Response 4: Thank you for your feedback. Upon reviewing the figures, we confirm that the colour ranges for both NDVI and NDBI have been consistently applied across all periods (2014 and 2023), and the same scaling rules are used in both cases. Since NDVI and NDBI represent distinct phenomena, separate colour bars are necessary to accurately indicate the different aspects of land degradation. We believe this approach is the most appropriate for presenting the data effectively.

Comment 5: Figure 7 also needs further embellishment.

Response 5: Thank you for the observation. The figure has also been further embellished for better viewing

Comment 6: The conclusion needs to be further summarized and condensed.

Response 6: Thank you so much for the suggestion. The conclusion has been further summarised and condensed from 29 lines (480-509) to 13 lines (480-493) for easier readability and assimilation

 

Thank you for your time and effort in reviewing our manuscript. This is much appreciated

 

Author Response File: Author Response.docx

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 and Suggestions for Authors

I am very glad to receive your email. My review comments are as follows:
The impacts of migration on land degradation are an interesting research topic. This study takes the Savannah Region of  Nigeria as the research object. However,  there are still many problems in this manuscript that need to be explained. It is suggested that the manuscript be  revised and resubmitted.

 
1.     Overall, the innovation of the paper needs to be further clarified.

2.     The abstract needs to be further modified and condensed.

3.     Overall, the manuscript requires a native English speaker to polish the language.

4.     The introduction part of the paper needs to be further condensed in order to highlight the existing research and  the purpose and significance of this research.

5.     How was research uncertainty assessed in this study?

6.     Is the number of 360 questionnaires in this study sufficient?

7.     Figure 1 needs further embellishment, not all figures need to display latitude and longitude information.

8.     The manuscript is more like a report than a research paper.

9.     The research data in this manuscript are crude and the charts are not aesthetically pleasing,  so it is recommended to redo them.

10.  The conclusion needs to be further condensed and summarized. 

 

Comments on the Quality of English Language

the manuscript requires a native English speaker to polish the language

Reviewer 2 Report

Comments and Suggestions for Authors Hello Authors, Your abstract is listed below.  See comments therein.  The Savannah Region of Nigeria (SRN) has experienced high levels of migration activities driven by diverse socio-economic and environmental factors. Based on the hypothesis that migration-induced land use change can lead to land degradation, especially in migration destination regions, this study investigates the impact of migration on land degradation in the SRN using a mixed-methods approach.   Comment: Well yes.  On its face this statement must be true.  But to allude to an hypothesis such as this you should attempt to suggest even here in the abstract, why such a hypothesis is of interest.  I am thinking particularly of these dimensions.  First, migrants from afar my not be conversant with local destination conditions so may be slow to adjust to local challenges.  Second, such migrants bring possibilities for innovation in light of prior experiences elsewhere.  And third, such migrants, given a lack of resources, may be drawn to sub-standard areas having limited developmental potential.  The study focused on two destination communities in the local government areas of Fagge and Gwagwalada, located in the Sudan and Guinea Savannah, respectively. A multi-stage stratified cluster sampling design was adopted to administer semi-structured and structured questionnaires to 360 respondents. The questionnaires highlighted respondents’ perceptions of land degradation issues resulting from migration. The analysis of respondents’ perceptions revealed that land degradation was the third most important challenge of migration, after insecurity issues and competition for jobs. 41.1% and 29.5% of the respondents agreed and strongly agreed, respectively, that migration exacerbates land degradation. Comment: Add a brief statement of reasons why this should be so.  To detect the existence of land degradation, land use and land cover change (LULCC) was mapped from the Landsat Analysis Ready Data repository for the years 2000, 2010, and 2020. Comment: it is not clear to me whether the presence of migrants causes or correlates with land degradation.  Would their presence on one hand stimulate degradation, while at the same time reflecting the ease of access to degraded environments offering limited development potential.  Also, why would their presence also in some ways foster improvements in the economy, and favorable land use changes if they have wealth to invest, a condition often not present of course.  And one would suppose the demand of migrants for services could lead to diminished economic vitality and neglect of local landscapes.   Our results show a decrease in vegetative cover by a total of 446.9 ha (2.09%) and 17,033.33 ha (51.34%), respectively, and an increase in the built-up areas by 492.26 ha (22.47%) and 2195.15 ha (18.37%) at the respective locations of Fagge and Gwagwaglada. Comment:  These are useful findings.  Please of course elaborate extensively in your main text.  Your hypotheses hardly begin to frame the processes at work, and hardly anticipate these valuable findings.  I would suggest reworking your hypotheses to shape the analysis more sufficiently.  The perceptions obtained from respondents regarding the existence of land degradation resulting from migration can aid policymakers and stakeholders in executing community-specific near- and far-sighted policies and actions as integral parts of developmental responses for adapting to the challenges of migration. Remote sensing-based analysis, in turn, may support localisation of related developments.  Comment":  Meaning?  Clarify.  Comment::Lastly, if you have good data re land cover then why do you also need data regarding resident perceptions? Comments on the Quality of English Language

Overall satisfactory.  Minor edits possible for clarity.  

Reviewer 3 Report

Comments and Suggestions for Authors

The article is very well written, more detailed commentary is attached.

Comments for author File: Comments.pdf