Is Abandoned Cropland Continuously Growing in China? Quantitative Evidence and Enlightenment from Landsat-Derived Annual China Land Cover Dataset

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper " Is abondoned cropland continuously growth in China? Quantitative evidence and enlightnment from Landsat-derived annual China land cover datasat " seems interesting study. In my opinion the most important part of research is data collection and then analysis with application annually derived landsat images. It enables to reveal the most important methods to derived existing cropland as well as ongoing farmland abondonement in China. I think that these results are articulated more strongly in the paper.

However, the paper have so many contents that are not justifying to research problem of this paper. These contents are making this paper too long and therefore it may be difficult to follow, especially to readers without deep knowledge on indicators and context. I recommend making concise and consolidating content of each chapter. Authors can read more and more background about farmland abondonment, then can make more concise background, methodology and even discussions.

For e.g.. in abstract. The first line of your abstract is not related to farmland abondonment issues. This content might be relevant to food security, food consumption. So I suggest you to write abstract indicating theoritical background of this paper.

Further, there is a lack of fact information like not only chinese, but tetter also to give global context that are requiring to assess of farmland abondonment. In the future, that kind of assessment might be required in other countries also. However, it would be better to give global changes and use of landsat images for deriving abondoned farmland.

Similarly, it requires to review existing approach or assessment methodologies also. They might be already developed, but not covering all the aspects of landsat use efficiency. Try to give different indicators of existing assessment methodologies.

Also after giving main theoretical basis of the study… you can elaborate how it is going on different global contexts.

Comments on the Quality of English Language

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

Very interesting paper! The article is of great importance, concrete solutions are proposed, which are ready for application by the policymakers. I have only a few minor suggestions:

Lines 38-40: Please, rewrite this sentence. It is not clear enough.

Line 157: Figure 1 - There is no reference to this figure in the text above. In addition, you should explain what the numbers in the agricultural natural zones mean. There is an explanation in a table below, but however, these numbers are mentioned for the first time here in Figure 1. Hu Line is also mentioned for the first time in the figure! You have to explain what it means! 

Lines 174 – 175: Reference missing!

Line 179: 1-14 represents – I suggest: 1-14 represents as follows:..

Lines 192 – 193: Add reference here!

Line 400: Discussion!

Line 522: Please capitalize the first letter in the sentence!

Line 525: cropland. and – Please, fix this! 

Kind regards!

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The authors proposed a method to identify abandoned cropland in China from 1991 to 2018 using 30 m remote sensing data combined with farm census data. The topic is relevant and crucial to the discussion regarding the ecological implications of agriculture expansion in susceptible areas for biodiversity loss and ecosystem services damage. The authors should explore further the debate concerning the nexus between food security and environmental conservation.

Some specific comments:
1) Introduction: I suggest updating the population data considering the UN's latest report on prospects for population growth from 2022.
2) I suggest including a deeper literature review on abandoned cropland worldwide, considering its hotspots in Asia, Latin America, and Africa.
3) The main goal of the piece has to be presented.
4) The authors mentioned that the overall accuracy of the LULC maps is 79,31%. However, they do not note the thematic land use types in such remote sensing image classification. Given the significance of the distribution of very distinct land use types across China, I suggest mentioning the land use types in the methodology.
5) How was the statistical data transformed/aggregated into the raster data? What were the computing strategies used?
6) Figure 1 is not precise. The number on the territory is not presented in the legend.
7) Figure 10 must be moved to the Results section.

Author Response

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Author Response File: Author Response.pdf