Forest Fire Mapping Using Multi-Source Remote Sensing Data: A Case Study in Chongqing

Round 1

Reviewer 1 Report

Forest fires are one of most severe natural disasters, which has a significant impact on the ecological security and social development. The manuscript focused on the forest fire monitoring and catalytic factor analysis based on multi-source remote sensing data and meteorological data. The study will be helpful to real-time monitoring the extent and intensity of forest fire, to accurately realizing its catalytic factors, and to effectively taking optimal fire prevention policies. However, the following suggestions are attached for improving your research.

1.      Unmanned Aerial Vehicle (UVA) is used in this study. However, I can’t find any introduction about it, such as how many bands are included in UVA? Has it a shortwave infrared band to get dNBR? When is it worked? Before or after the forest fires occurred to scan the burned areas? How to deal with the UVA data? All should be described in the manuscript.

2.      SPI is a universal method in describing meteorological drought globally. The calculation can be found easily via internet. However, in this manuscript, its calculation is not as same as others. You can change its abbreviation to another word if you want to use your calculation.

3.      The threshold method is your key point in this manuscript. But I don’t know how you get the critical threshold to judge fire intensity. Therefore, the subsequent results will become water without source and wood without root.

4.      When concerning the analysis of the catalysis factors about meteorological factors, all are qualitative description. The quantitative assessment is strongly added to find the prevailing factors. It will be helpful to take effective fire prevention measures.

5.      Again, how to determine different severity for different samples in Fig.2, which also concerns the critical threshold.

6.      Several minor suggestions:

a)         What data source and what RGB composition method is used in Fig.3

b)         The difference of wind speed in Fig. A3e, more than 30 m/s on one day, is an amazing difference, please check it.

c)         The elevation and slope for each fire area in Fig. A4 and Fig. A5 can be added in Fig. 1 and be replaced the real-time images.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Lines 32-33: Scholars have been paying attention to forest fire research for at least 150 years. Please rephrase this statement.

Line 97: What kind of “sample data” were collected? Soil samples, vegetation samples, mapping the extent of burned area, etc? Please be more specific. Are these the images noted in lines 139-142? If so, it is good to mention that they are UAV images in the introduction.

Lines 112-114: As droughts are often defined by their severity within a season, it is unusual to see droughts defined as “days of drought” such as in this example. How were these days of drought determined? Are these days with less than average precipitation? Are these days with a soil moisture below a certain threshold? Are these consecutive days of zero precipitation? Are these days with a relative humidity below a certain amount? This is explained more clearly in Figure 10 and the accompanying text. Perhaps using “days of drought conditions as defined by …” would be helpful in the introduction as the full explanation arrives later in the paper.

Lines 159-161: Figure 1 includes the meteorological stations, but it is difficult to determine which station name corresponds with which station. This is especially true for the 3 stations that are located quite close to one another. Having different symbols or colors that are explained in the figure caption can help separate the stations.

Line 188: Define the statistical methods used for the random selection.

Figures 2, 8, and Section 3.2: Figure 2 demonstrates that high severity fires often follow ridgelines. These locations were randomly selected (Line 188) where this selection then influences the threshold values. The true randomness of the selections needs to be clearly defined, otherwise the argument presented in this section becomes circular. (As in, if sites were selected due to their topography, and if the topography influences the severity, then the examination of how topography influences fires is based on this initial selection).

Section 4.1 and Supplementary Information: What influence does slope aspect play in the fire severity of these study regions? Slope aspect is often a control of soil moisture, and therefore should be included in this section.

Section 4.2: This section provides a good synopsis of possible ignitions directly or indirectly caused by human activity. Did the authors also examine any data for possible natural ignitions from thunderstorms during the study time period?

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have revised the manuscript based on the comments of reviewers. The manuscript was significantly improved.

Author Response

Thank you for your suggestions