Quantification of Vegetation Phenological Disturbance Characteristics in Open-Pit Coal Mines of Arid and Semi-Arid Regions Using Harmonized Landsat 8 and Sentinel-2
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsDear authors, I have read your manuscript „Quantification of vegetation phenological disturbance characteristics in open-pit coal mines of arid and semi-arid regions using Harmonized Landsat 8 and Sentinel-2“ and got concerns about the novelty/soundness of your work. I realized that your paper/concept is very much the same as previously published paper by Sun et al. 2022 (https://www.sciencedirect.com/science/article/pii/S1569843222000164) . Weirdly, none of the authors of the manuscript submitted to RS is a co-author of the mentioned paper - Sun et al. 2022.
The chapter Data acquisitions and pre-processing is not sufficient. For instance it is not clear what was the time window/acquisition dates of S2 and Landsat time series. In addition you declare you did following preprocessing: “This dataset underwent a series of processing steps including atmospheric correction, spatial registration, BRDF correction, bandpass adjustment… Not really clear why and how this was done? Moreover, the way dust pollution was assessed is not clearly described. Not clear how 1km monthly PM 2.5 and PM 10 and the 1km monthly precipitation dataset were statistically assessed compared to smoothed NDVI time series. In the Fig. 6 clear seasonality can be seen and doesn’t really make sense to do linear regression.
I was quickly checking the methods/equations. I could see, although you basically use the same ones as in the mentioned paper - Sun et al. 2022, you use different alphabets for the same variables, and you give different definition for them, for instance for eq. 1 - v1 and v2 are the background and amplitude of NDVI over the entire year, however you say ?1 and ?2 correspond to the background greenness value min [???(?)] and the magnitude of change max[???(?)]−min[???(?)]. For the equation 2 you introduce the new parameters v1, v2, v3 and v4, I don’t think that m1 parameter is described correctly.
In summary this study uses well know and many times tested methods e.g. commonly used models ,e.g. Double Logistic filter (DL) and Asymmetric Gaussian filter (AG) were employed to smooth the initial NDVI time series. It is not clear how the further assessment was done e.g. dust pollution. The employed methods might have not been used properly (e.g. the problem with equations). For those reasons I have to reject this paper in a current form.
Comments on the Quality of English LanguageEnglish looks fine but for instance the way the Equations are described is not very clear.
Author Response
Thank you very much for your comments on our manuscript. These comments are very helpful for us to revise and improve the paper. According to the your comments, we have made extensive modifications to our manuscript and clarified the differences from Sun et al.'s research. Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThere are some major concerns that should be taken care of in a future version of the manuscript.
Major concerns:
1. The introduction currently lacks a clear statement of the motivation behind the study. The introduction, as currently written, leans heavily towards discussing the technological aspects (P2-3) but lacks a comprehensive discussion about the interplay between mining activities and background water conditions, and how these two factors influence vegetation phenology. Given that these are the key factors highlighted in your title, it is crucial to incorporate a detailed review and discussion on this relationship. This will not only provide readers with a foundational understanding of the primary factors under investigation but also emphasize the relevance and significance of your research on mining-phenology relationship within the broader context of phenological studies.
2. The methodology part lacks validation or assessment to determine the accuracy and reliability of these derived LSP metrics. Are those vegetations natural plants or actively managed by humans? There is also no description of the cumulative impacts of mining distance.
3. Given that you utilized the HLS, it is better to include the comparison between LSP derivation from other satellite sources.
4. It is hard to understand “Disturbance distance and degree of vegetation phenology from open-pit mining activities”. Clarify the meaning of "degree" in this context. If it refers to the response of the LSP to mining activity, then it would be beneficial to label it more descriptively, e.g., "response magnitude" or "phenological response intensity." Results need more consideration.
5. Discussion needs comprehensive consideration of logic. What is the link between mineral dust and mining distance? The results analyzed mining distance while the discussion on dust emissions? Key factors influence the LSP, the precipitation effect is kind of vague and qualitative, not convincing. There is no clear discussion on how mining and background arid conditions drive the phenology change.
6. There are repeated labels in the Figures, please revise the Figures.
Minor comments:
Line 47-49: two reference cannot be separated by name
Line 52: What is the “limited monitoring frequency”? Why it is important, particularly in the phenology study that is related to mining influence?
Line 86: why choose only year 2022 to study the mining influence on LSP? How about the remaining years, do they have the consistent evidence?
Line 94-97: revise
Figure 1b: revise the color scheme of the DEM.
Line 100-101: revise
Line 140: what is the temporal distribution of the NDVI time series?
Line 141-147: land use types are needed to illustrate the natural phenology change
Line 149-151: what is the influence of precipitation on LSP? There are no quantitative results and discussion (only qualitative description) on this point.
Line 161: how you define the threshold and how you validate the derived SOS/EOS with field observations?
Figure 5: the exponential relationships between LSP and distance looks vague in XD mining area.
Line 307-321: what is the cumulative effect of mining disturbance? If you are expecting the central areas (e.g., 1000m to 1200m) to have the greater changes in LSP, how these changes are linked to mining influence but not changes in vegetation types or other indicators? In addition, the changes in EOS do not necessarily show greater changes in central areas.
Figure 6: the last figure should be Figure 7 and do you mean correlation between phenological metrics and mineral dust? Revise the caption. Are those PM data from sites? Why do not study the correlations based on pixel level?
Author Response
Thank you very much for your comments on our manuscript. These comments are very helpful for us to revise and improve the paper. According to the your comments, we have made extensive modifications to our manuscript. Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsI enjoyed reading the manuscript. The authors have written this manuscript very well. The article is comprehensive and timely to educate innovative methods of characterizing phenological disturbances in the coal mine lands. It flows well, follows the journal guidelines, and has recent and relevant references. The presentation of the methodology in a graphical format (figure 2) is impressive. The authors have discussed the limitations honestly and have provided ways to address these limitations in future research. The results, I believe, have merits in addressing pollution caused by pit coal mines in the surrounding area. The article could be improved significantly by addressing the following points:
Line 50 -Explain the “Land Trendr algorithm” and its specialty in a sentence. I wonder why you did not intend to use it in this research.
Line 58 -delete extra “and”
Line 73 – The use of “large scale ecosystems along with “course spatial resolution… and fine scale .. information.” is confusing here. Revise the sentence for clarity.
Line 89: Explain why arid and semi-arid regions were used in this study and how you sampled both regions for data collection and analysis.
Line 101 - Was your study area a part of Mongolia country? Is it Zungeer or Zhungeer city? Figure 1 legend states Zhungeer .
Explain open-pit mining areas a bit more- stating how mining operations are conducted, who owns these lands, and how these lands are reclaimed in the post-mining time to restore lost vegetation or soil.
Which one were arid lands you included in the study site?
Line 119 – Would you characterize “surrounding vegetation,” e.g., species, forest or pasture or grass, agricultural lands, etc.? Are they primary forest/vegetation or regenerated succession forests or grasses?
Figure 1- increase the symbol of Zhungeer City to make it more visible.
Line 135 Provides a reference for the Python web crawler
Line 139 Check spelling- it should be “delete,” not delet
Line 140 Did you derive NDVI images or use available ones? Not clear
Lines 1577-158: What were the criteria for identifying “polluted pixels”?
Line 160: Explain double logistic and Asymmetric Gaussian algorithms with citation(s). Why would you need to use both?
What software did you use for data analysis?
Table 1 heading – Should you say “Means” not mean?
Line 300 . Cite figure Number is it Figure 5 you are referring to?
Lines 315-316- Does this mean directional disturbance patterns were minimal, or did you not intend to measure?
Line 340-341: Was it a regular record or considered an extreme weather event?
The discussion section (Lines 313-348) needs more substantiation of results by adding additional relevant citations and discussing their connections to the results of the current study.
I am unsure if this study categorically identified and explained significant variance in disturbances between arid and semi arid regions. Need to make this clear in the discussion section.
Comments on the Quality of English LanguageI did not notice major issues regarding the quality of English language use in this manuscript.
Author Response
Thank you very much for your comments on our manuscript. These comments are very helpful for us to revise and improve the paper. According to the your comments, we have made extensive modifications to our manuscript. Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsThe paper deals with an interesting theme highly topical in the context of the current World research trends. This paper presents quantification of vegetation phenological disturbance characteristics in open-pit coal mines of arid and semi-arid regions using harmonized Landsat 8 and Sentinel-2 of Zhungeer City. In order to meet the objective of the paper, the authors chose an adequate methodical apparatus based on the use of relevant geospatial data and modern geoinformatics equipment. I appreciate especially the methods such as constructing an NDVI spatiotemporal cube, developing a disturbance identification model for mining areas, and analyzing the cumulative effects of open-pit mining and the impact of mineral dust on vegetation phenological metrics, as well as the interpretation of the obtained results. The results reveal an exponential variation in vegetation phenological metrics with increasing distance from the mining areas of Heidaigou-Haerwusu (HDG-HEWS), Mengxiang (MX), and Xingda (XD) in northwest China. These research results are expected to provide a reference for the formulation of dust suppression measures and ecological restoration plans for open-pit mining areas.
The title of the paper is acceptable and adequate and no major changes are necessary. I find the abstract acceptable and well structured. The manuscript has a sufficient scientific value and the information provided represents widening of knowledge. The conclusions are based entirely on the results and the methods used are adequate. The relation between the scientific value and the extent is acceptable. The language and style of the text are at an acceptable level. The tables and illustrations used in the paper are adequate; however I consider the number of references incomplete. The topic dealt with in the paper is also covered by other authors in papers.
I have no other remarks of a rather significant nature concerning the paper. The results are valuable and the scientific paper brings new original data. The manuscript is acceptable after minor revision with minor amendments required; no re-review is necessary. I recommend the paper for the print. The paper was of very good quality and it was a pleasure to read and review it.
So no elements that should be corrected:
Conclusion: any limitation of your research? So please add it.
I recommend amending the references. This issue is also covered by the newer papers from other authors. I recommend adding some papers into the references.
Fig. 1. Is Zhungeer City in China or in Mongolia (see chaper „study area“) ?
Figure 5 –the numbers of graph are very small.
As you see, there is not too much to correct according to my opinion.
Good luck in your future scientific work.
Author Response
Thank you very much for your comments on our manuscript. These comments are very helpful for us to revise and improve the paper. According to the your comments, we have made extensive modifications to our manuscript. Please see the attachment.
Author Response File: Author Response.pdf
