Quantifying Land Degradation in Upper Catchment of Narmada River in Central India: Evaluation Study Utilizing Landsat Imagery

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

I like the idea of linking land cover with temperature and degradation.

Unfortunately, I think there are serious issues with the methodology. I have to be a bit careful here as it is considered inappropriate for a reviewer to recommend referencing their own work. The main issues I have are;

1) no clear definition of what you mean by "forest" - are you using the term as "land cover" i.e. a large area covered in large trees or as a "land use" i.e. land that is not used for housing, transport, water, crops etc.

2) no list of what the "degradation factors" actually are. Sorry missed the supplementary material the first time through.

3) use of maximum likelihood in a semi-natural environment where there will be ecotones and graduations.

4) the imagery is from just after the rains (monsoon) to several months afterwards, this will affect the classification a lot.

5) no discussion of the observation that some of your land cover transitions seem "unusual", e.g. in table 4 built-up land becoming forest, in some situations I could accept that a new urban development can after a few decades look more "woody" as residents plant shade trees, especially things like mango which develop large dense canopies quite quickly, but not that quickly. Water turning into built, implies land drainage perhaps?and this leads to the next point.

6) you have "maps" with an overall accuracy of ~90%, that is ~10% error in each one, if we take a crude approach 0.9 x 0.9 = 0.81 correct when comparing two maps ... but somewhere in this ~20% error or uncertainty, you are confident you have identified 3% of change.

Maximum Likelihood is quick and easy and inappropriate for your study.

Author Response

Response to reviewers’ comments

Title of paper: Quantifying Land Degradation in the Upper Catchment of
Narmada River in Central India: An Evaluation Study Utilizing Landsat Imagery

We are expressing our gratitude and thanks to reviewers and editor for critically reviewing our paper and giving valuable suggestions for revision and modification of the manuscript. We have addressed the relevant issues raised by anonymous reviewers and editor in different sections of MS, kindly see in track mode and point to point responses has been provided below:

 

Response to comments of reviewer 1#

Comment 1: I like the idea of linking land cover with temperature and degradation.

Response: Thanks for your appreciation.

Comment 2: Unfortunately, I think there are serious issues with the methodology. I have to be a bit careful here as it is considered inappropriate for a reviewer to recommend referencing their own work.

Response: As pointed out by the reviewer, we are modified changes and removed own work from the methodology section and thoroughly improved in the revised manuscript.

Comment 3: No clear definition of what you mean by "forest" - are you using the term as "land cover" i.e. a large area covered in large trees or as a "land use" i.e. land that is not used for housing, transport, water, crops etc.

Response: Thanks for your notifications

A forest is a large area predominantly (>50%) covered by tree stands and vegetation. It serves as a complex ecosystem that provides habitat for various wildlife, supports biodiversity, and plays a crucial role in carbon storage, climate regulation, and water cycle maintenance. Forests can vary significantly in terms of species composition, structure, and function, ranging from tropical rainforests to temperate deciduous forests and boreal forests. They are essential for human life, providing resources such as wood, food, fodder, flosses, nuts, and recreational opportunities. Land is used for various purposes and spatial phenomena, especially those of the natural environment, prototypes of classes such as different types of land cover, agriculture, build up area, waterbodies, forest, follow land etc. were identified and have clear spatial extent.

Comment 4: Sorry missed the supplementary material the first time through.

Response: Thanks for pointed out and we are attached supplementary figures (SF1) and supplementary table (ST1 & 2) after references as suggested by the reviewer.

Comment 5:  Use of maximum likelihood in a semi-natural environment where there will be ecotones and graduations.

Response: Thanks, Maximum likelihood algorithm (MLA) is a statistical method commonly used in ecology to estimate parameters of a model that best explain the observed data. In a semi-natural environment with ecotones—transition zones between different landscape classified and forest community estimated through MLA with the help of satellite images in the present study. 

Comment 6: the imagery is from just after the rains (monsoon) to several months afterwards, this will affect the classification a lot.

Response: Thanks for your kind suggestions

The timing of acquiring satellite imageries across different seasons provides a comprehensive view of changes and patterns, allowing for more accurate and contextually relevant analysis. It helps in understanding temporal dynamics and in making informed decisions based on timing and cloudy region. The timing of satellite imagery relative to the monsoon can significantly impact classification results.

Comment 7: No discussion of the observation that some of your land cover transitions seem "unusual", e.g. in table 4 built-up land becoming forest, in some situations I could accept that a new urban development can after a few decades look more "woody" as residents plant shade trees, especially things like mango which develop large dense canopies quite quickly, but not that quickly. Water turning into built, implies land drainage perhaps? and this leads to the next point.

Response: Thanks, the built-up area was increased by almost 300% with the conversion of part of agriculture, fallow lands, wooded forest lands and waterbodies too. Author’s mentioned in the results and discussion section of the manuscript.

Comment 8: You have "maps" with an overall accuracy of ~90%, that is ~10% error in each one, if we take a crude approach 0.9 x 0.9 = 0.81 correct when comparing two maps ... but somewhere in this ~20% error or uncertainty, you are confident you have identified 3% of change.

Response: Thanks, the probability that both maps are correct in the same place, this is a useful result that shown procedure or detection approach is strong enough to identify actual changes even in the presence of map in accuracies. This change is real despite the uncertainty in the maps. Changes has been made in Table 2. Thanks for your kind advised.

Comment 9: Maximum Likelihood is quick and easy and inappropriate for your study.

Response: Thanks for your guidance

The maximum likelihood algorithm is a powerful tool for ecologists studying semi-natural environments with ecotones, helping to reveal complex ecological dynamics and inform conservation strategies.

Reviewer 2 Report

Comments and Suggestions for Authors

I find the article interesting, which deals with the important issue of land use change and its role for the various components of the environment. The article has details of the methodology described-classical for this type of comparative research. I recommend the article for publication after taking into account the following comments.

1) The Introduction chapter is too long. There is a lack of focus on the literature review in strictly narrowing down the purpose of the study.

2) Please provide more information on the seasons of image acquisition in each year . How does this affect the results obtained?

3) To increase the clarity of the article, please disentangle the Results and discussion section. In the first one, the reader should clearly know the results of the study in turn, in the second one, reference should be made to the existing knowledge in this area.

4) For the quality of the river itself, not only the forms of land use within the entire basin, but also in the coastal zone are important. Please provide more details on this topic. Proper land use can provide a protective buffer against pollution.

5) 4.7. Future Perspective: An Integrated Narmada River Basin Restoration Approach for Degraded Land Reclamation . Although the subsection was intended by the authors to be applied, it is not such. I believe that the postulates indicated by the authors are purely theoretical, which, given the diverse economic and social needs of the region, will not be realized. To put it another way-what would the current state (which has lasted for at least two decades) be replaced with in exchange for the interruption/removal of significant land degradation?

Author Response

Response to reviewers’ comments

Title of paper: Quantifying Land Degradation in the Upper Catchment of
Narmada River in Central India: An Evaluation Study Utilizing Landsat Imagery

We are expressing our gratitude and thanks to all anonymous reviewers and editor for critically reviewing our paper and giving valuable suggestions for revision and modification of the manuscript. We have addressed the relevant issues raised by anonymous reviewers and editor in different sections of MS.  Details are as follows:

Response to comments of reviewer 2#

I find the article interesting, which deals with the important issue of land use change and its role for the various components of the environment. The article has details of the methodology described-classical for this type of comparative research. I recommend the article for publication after taking into account the following comments.

Comment 1: The Introduction chapter is too long. There is a lack of focus on the literature review in strictly narrowing down the purpose of the study.

Response: Modified the Introduction section and improved the literature review as suggested by the reviewer.

Comment 2: Please provide more information on the seasons of image acquisition in each year. How does this affect the results obtained?

Response: The timing of acquiring satellite imageries across different seasons provides a comprehensive view of changes and patterns, allowing for more accurate and contextually relevant analysis. It helps in understanding temporal dynamics and in making informed decisions based on timing and cloudy region. The timing of satellite imagery relative to the monsoon can significantly impact classification results.

Comment 3: To increase the clarity of the article, please disentangle the Results and discussion section. In the first one, the reader should clearly know the results of the study in turn, in the second one, reference should be made to the existing knowledge in this area.

Responses: Changes has been made as per reviewer suggestions.

Comment 4: For the quality of the river itself, not only the forms of land use within the entire basin, but also in the coastal zone are important. Please provide more details on this topic. Proper land use can provide a protective buffer against pollution.

Response: The coastal zones of the Narmada basin are significant for various land use activities and ecological services, such as carbon sequestration, nutrient cycling, and habitat provisioning, which are vital for maintaining ecosystem health. Coastal areas often host diverse ecosystems, including mangroves, wetlands, and estuaries, which are crucial for supporting a wide range of flora and fauna. It’s play a crucial role in managing water resources, acting as buffers against flooding and erosion. They help maintain water quality and regulate the hydrological cycle. Agricultural runoff, industrial discharge, and urban waste can contaminate soil and water resources, further contributing to degradation. Overall, the coastal zones within the Narmada basin are crucial for balancing ecological health, economic development, and community well-being, necessitating careful management and conservation efforts. Authors has made changes as suggested by the reviewer.

Comment 5: 4.7. Future Perspective: An Integrated Narmada River Basin Restoration Approach for Degraded Land Reclamation. Although the subsection was intended by the authors to be applied, it is not such. I believe that the postulates indicated by the authors are purely theoretical, which, given the diverse economic and social needs of the region, will not be realized. To put it another way-what would the current state (which has lasted for at least two decades) be replaced with in exchange for the interruption/removal of significant land degradation?

Response: Addressing land degradation in the Narmada basin requires integrated management strategies that focus on sustainable land use, reforestation, improved agricultural practices, and community engagement. Efforts to restore degraded land and promote conservation can help mitigate various issues. Authors has made changes as per advised by a reviewer and text has been incorporated in the manuscript.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

While you have addressed some issues, thank you, I feel you could have done more.

I still don't know what you mean by "forest" neither as a land-cover (density, phenology, canopy cover, hight etc), nor, do I know what the "use" is, timber, conservation, grazing, or how it is managed (wild, plantations, selective logging). I see no discussion of the LU of the LULC ...

I think a discussion is needed as to your confidence in the amount of change when the change is much less than the error rate.

I think using maximum likelihood just because other people have used it, is rather weak, especially as you have access to ERDAS.

Author Response

Dear Reviewer, 

Thanks for your acceptance of our revised article

As per your suggestions, we have added a paragraph below Figure 6 in the discussion section (kindly see the highlighted text), hope it will suit your requirements. 

 

Thanks again 

Regards 

Prof Amit Kumar