Spatiotemporal Dynamics and Climate Influence of Forest Fires in Fujian Province, China

Round 1

Reviewer 1 Report

Reviewer’s Report on the manuscript entitled:

Spatiotemporal dynamics and climate influence of forest fire in Fujian Province, China

The authors analyzed the spatiotemporal variation in forest fire occurrence in Fujian Province, China using MODIS data from 2001 to 2016 and metrological data. The manuscript is generally suitable for publication in Forests, however, the presentation and literature review must be improved as well as validation. Please see below my comments:

Line 12. Please say spatiotemporal instead of spatial and temporal

Line 16. Please define MODIS.

The Introduction needs further improvement particularly the literature. Please add a paragraph and add the suggested articles below with a brief description of each:

There is a software package called Jumps Upon Spectrum and Trend (JUST) that is applied for monitoring vegetation time series in near-real-time for detecting and classifying disturbances/jumps in the series caused by several factors such as fire. The paper describing the package is:

https://doi.org/10.1007/s10291-021-01118-x

I suggest the authors to review this paper and include it here along with its accompanying paper for near-real-time monitoring of forest fire entitled:

“The potential of the least-squares spectral and cross-wavelet analyses for near-real-time disturbance detection within unequally spaced satellite image time series. (Remote Sensing)”

The use of land surface temperature in generating forest fire danger map:

https://doi.org/10.3390/s20040984

And the impact of climate change and its assessment on Wildfire risk:

https://doi.org/10.3390/f6093197

Line 60. Please define MODIS.

At the end of the Introduction, please add a paragraph to mention how the rest of the article is organized. Something like: The rest of the paper is organized as follows. In Section 2, the study region, datasets, and methodology are described. Section 3 demonstrated the results, etc.

Line 76. Please add a few lines to describe how vulnerable these types of trees are to fire and how they can catch fire and spread, their density, etc.

Figure 1. Please add the scale bar in kilometers, and also increase the font size of the numbers a bit with their resolution.

Line 63. The abbreviation for MODIS is Moderate Resolution Imaging Spectroradiometer.

Line 101. It should be Fire Weather Index (FWI). Also, please use capital letters always when you define the acronyms and ensure that all the acronyms are defined the first time they appear.

Line 108. Please change the this heading to “Methods”

Line 109-112. Mann-Kendall test has several shortcomings. I list some of its shortcomings here. Firstly, the seasonality observed in vegetation time series must be removed before performing the text otherwise the test result can easily mislead the researchers. Secondly, the missing values can alter the Mann-Kendall test results, etc. These must be discussed in the Discussion section. Furthermore, the JUST software that I suggested above has a least-squares based season-trend fit tool that can simultaneously consider seasonal and trend variation in the time series statistically and performs well in the absence of the missing values because the time vector is also considered in JUST unlike the Mann-Kendall algorithm.

Figures 4, 5, 6. The font size should be enlarged, and the figure quality should be improved.

I do not see any validation here. Authors should show some validation results or at least confirm or discuss their results in the light of other similar studies for their study region. This can be mentioned also in the Discussion section.

Line 263. The limitations of this study should be mentioned in the Conclusion.

Thank you

Best regards,

Author Response

1. Response to comment: Line 12. Please say spatiotemporal instead of spatial and temporal

Thank you for the suggestion. We have changed spatial and temporal to spatiotemporal. See Line 14

 

2. Response to comment: Line 16. Please define MODIS.

Thank you for the suggestion. MOIDS has been defined. See Line 19

 

3. Response to comment: The Introduction needs further improvement particularly the literature. Please add a paragraph and add the suggested articles with a brief description of each.

We added and introduced related articles to improve the introduction as suggested by Reviewer#1 in the second paragraph of the introduction. See Line 46-57

 

4. Response to comment: Line 60. Please define MODIS.

We have defined MODIS in Line 16 according to Reviewer#1, so we will not change it here. See Line 16

 

5. Response to comment: At the end of the Introduction, please add a paragraph to mention how the rest of the article is organized. Something like: The rest of the paper is organized as follows.

We have added one sentence to briefly describe the structure of the article. See Line 94-97

 

6. Response to comment: Line 76. Please add a few lines to describe how vulnerable these types of trees are to fire and how they can catch fire and spread, their density, etc.

We have added descriptions of the tree species, flammable nature, environment, and the type of fire in which it predominates at this location. See Line 107-109

 

7. Response to comment: Figure 1. Please add the scale bar in kilometers, and also increase the font size of the numbers a bit with their resolution.

We have modified Figure1 by adding the scale bar in kilometers and increase the font size of the numbers a bit with their resolution. See Line 116-117

 

8. Response to comment: Line 63. The abbreviation for MODIS is Moderate Resolution Imaging Spectroradiometer.

We have changed the spelling of MODIS to Moderate Resolution Imaging Spectroradiometer. See Line19

 

9. Response to comment: Line 101. It should be Fire Weather Index (FWI). Also, please use capital letters always when you define the acronyms and ensure that all the acronyms are defined the first time they appear.

Thank you for the suggestion, We reexamined the definition of letters in the article; and corrected the spelling of FWI. See Line 70

 

10. Response to comment: Line 108. Please change the this heading to “Methods”

We have changed ’Data analysis’ to ‘Methods’. See Line 144

 

11. Response to comment: Line 109-112. Mann-Kendall test has several shortcomings. I list some of its shortcomings here. Firstly, the seasonality observed in vegetation time series must be removed before performing the text otherwise the test result can easily mislead the researchers. Secondly, the missing values can alter the Mann-Kendall test results, etc.

It is really true as Reviewer suggested that Mann-Kendall test has several shortcomings, Meanwhile, I read the article about the software: the Jumps Upon Spectrum and Trend(JUST) based on Reviewer#1's suggestion, It is found that the software is more suitable for data analysis with Stable and orderly changes and longer than one Stable History Period(SHP). However, the length of time series of data in this study is limited and the signal-to-noise ratio is low. Mann-Kendall test may be more appropriate. For details, see Line 59-72

 

12. Response to comment: Figures 4, 5, 6. The font size should be enlarged, and the figure quality should be improved

We have improved Figures 4, 5, 6 by enlarging the font size and the figure quality. See Line 219 225 237

 

13. Response to comment: Authors should show some validation results or at least confirm or discuss their results in the light of other similar studies for their study region. This can be mentioned also in the Discussion section.

As suggested, we have compared and verified the research results with similar studies in the study area or similar studies in neighboring areas in the discussion section. See Line 266 , 272-274, 293-296,

 

14. Response to comment: Line 263. The limitations of this study should be mentioned in the Conclusion.

In the discussion section, we explained the limitations of the study according to the suggestions and Pointers of Reviewer#1.See Line 305-314

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper looks an interesting one in the face of climate change. Also, this paper is critical for the scientific communities in China and elsewhere to know about the potential havoc of forest fire these days. However, I have few comments in improving the manuscript as such:

1. The abstract looks good. However, a little technical background such as MODIS -spatial and temporal resolution can enhance the understanding for readers. Also, an additional sentence of detail method and reducing one sentence in the concluding part may make it better.
2. couple of articles could be included to demonstrate the world context as such: https://www.mdpi.com/2076-3417/11/21/10155 and https://www.mdpi.com/1424-8220/18/5/1570 might be assisting the authors to see the potentials of high resolution images and it's utilities in delineating forest fire danger in the north American context. You might want to take a look at the works to enhance the literature in the introduction (second paragraph)
3. Its interesting to see the mann-Kendall model application. however, I suggest that the authors should incorporate a section of how did they eliminate cloud pixels. during the forest fire season, the critical aspect of removing the cloud pixels from the obtained images. Did the authors perform any specific algorithm for this? Moreover, how did the author validate the information were missing in the method part. this should be incorporate. 
4. The correlation looks good. However, if the authors could plot a 1:1 line with MODIS info: station data to validate the obtained outcome, might help the readers easily for understanding the suitability of this model and its implications.
5. Other areas look good.

Author Response

1. Response to comment: a little technical background such as MODIS -spatial and temporal resolution can enhance the understanding for readers. Also, an additional sentence of detail method and reducing one sentence in the concluding part may make it better.

We made some changes to the introduction including an additional sentence of detail method and reducing one sentence in the concluding part. See Line 18-19

2. Response to comment: couple of articles could be included to demonstrate the world context as such: https://www.mdpi.com/2076-3417/11/21/10155 and https://www.mdpi.com/1424-8220/18/5/1570 might be assisting the authors to see the potentials of high resolution images and it's utilities in delineating forest fire danger in the north American context. You might want to take a look at the works to enhance the literature in the introduction (second paragraph)

It is really true as Reviewer suggested that the two articles on the application of high resolution imaging helped us understand its role in forest fires and increased the knowledge gap in this area, which we have supplemented in the introduction. See Line 42-44

 

3. Response to comment: the authors should incorporate a section of how did they eliminate cloud pixels during the forest fire season, the critical aspect of removing the cloud pixels from the obtained images. Did the authors perform any specific algorithm for this? Moreover, how did the author validate the information were missing in the method part. This should be incorporate.

I supplement the acquisition and processing of image data, as well as the problem of cloud covered area, and briefly introduce the verification. No other algorithms are used for data processing in this study. See Line 119-124 for detailed modifications

 

4. Response to comment: if the authors could plot a 1:1 line with MODIS info: station data to validate the obtained outcome, might help the readers easily for understanding the suitability of this model and its implications

We made an attempt according to Reviewer's opinion, but with too many lines in the picture, it would be impossible to distinguish and make a good judgment. If there are too few lines, the length of the article would be greatly increased, and there would be no effective comparison. Therefore, no change was made

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I would like to thank the authors for addressing my comments. The manuscript is improved. I still have some comments:

Line 54. It should be "Ahmed et al. [16] proposed ..." not "Razu proposed ...".

Line 55. Please remove "at an Area of Interest (AOI)[18]"

Line 55. Hyunjin is not in the references. Line 57. The reference [16] is incorrectly inserted here. Please check to ensure that the references are properly cited throughout the entire manuscript.

Line 62. It should be "Least-Squares Spectral Analysis (LSSA)" not "Least-Squares Wavelet Analysis (LSWA)".

Line 64. Please replace "seasonal component, trend component, disturbance component[14]." with "trend, seasonal, and remainder components [15]."

Line 65. Please replace "this method" with "the NRT method". Also, it should be "... at least two-year Stable ..." not "... at least two Stable ..."

Reference [22] and [47] are the same. Remove [47]. The references must be checked one by one to ensure they are correctly cited in the paper in the right location. Furthermore, their format and style must be consistent.

Line 73-74. This sentence "Therefore, when the length of ...." is incorrect. Please remove. When the data is limited, Mann-Kendall performs even worse! You need to do some pre-whitening/boot-strapping in advance: see for example:  

https://doi.org/10.1002/hyp.1095

Line 98. Grammar issue: "discusses" not "discuss"

Finally please very carefully proofread the manuscript

Regards,

           

Author Response

1. Response to comment: Line 54. It should be "Ahmed et al. [16] proposed ..." not "Razu proposed ..."

Thank you for the suggestion. We have changed “Razu proposed ...” to "Ahmed et al. [16] proposed ...". See Line 54

 

2. Response to comment: Line 55. Please remove "at an Area of Interest (AOI)[18]"

Thank you for the suggestion. "at an Area of Interest (AOI)[18]" has been removed. See Line 55

 

3. Response to comment: Line 55. Hyunjin is not in the references. Line 57. The reference [16] is incorrectly inserted here. Please check to ensure that the references are properly cited throughout the entire manuscript.

Hyunjin’s article in reference section 18, Because of errors in author abbreviations when cited Hyunjin’s article. At the same time, we have checked and modified the reference cited and format of all papers according to the reviewer’s suggestion. See Line 55

 

4. Response to comment: Line 62. It should be "Least-Squares Spectral Analysis (LSSA)" not "Least-Squares Wavelet Analysis (LSWA)".

We have changed "Least-Squares Wavelet Analysis (LSWA)" to "Least-Squares Spectral Analysis (LSSA)". See Line 62-63

 

5. Response to comment: Line 64. Please replace "seasonal component, trend component, disturbance component[14]." with "trend, seasonal, and remainder components [15]."

We have changed "seasonal component, trend component, disturbance component[14]." to "trend, seasonal, and remainder components [15]." . See Line 64

 

6. Response to comment: Line 65. Please replace "this method" with "the NRT method". Also, it should be "... at least two-year Stable ..." not "... at least two Stable ..."

We have replaced "this method" with "the NRT method" and changed ""... at least two Stable ..." to "... at least two-year Stable ...". See Line 64-65

 

7. Response to comment: Reference [22] and [47] are the same, Remove [47]. The references must be checked one by one to ensure they are correctly cited in the paper in the right location. Furthermore, their format and style must be consistent.

We have remove [47] and checked and modified the reference cited and format.

 

8. Response to comment: Line 73-74. This sentence "Therefore, when the length of ...." is incorrect. Please remove. When the data is limited, Mann-Kendall performs even worse! You need to do some pre-whitening/boot-strapping in advance: see for example: https://doi.org/10.1002/hyp.1095

Thank you for the suggestion. We have removed the sentence. See Line 72. In addition, I would like to thank the Reviewer for two valuable comment, which provided me with a deeper understanding of relevant scientific methods 

 

9. Response to comment: Line 98. Grammar issue: "discusses" not "discuss"

Thank you for the suggestion, We have changed "discuss" to "discusses". See Line 96

Please see the attachment.

Author Response File: Author Response.doc