Disaster Mechanism and Evolution Characteristics of Landslide–Debris-Flow Geohazard Chain Due to Strong Earthquake—A Case Study of Niumian Gully

Round 1

Reviewer 1 Report

The work of He et al. present the case study of a geohazard chain with landslide and subsequent debris flow that was initiated under strong earthquake. Despite the fact that available data is very scarce, authors manage to reconstruct the sequence of events of the geohazard chain. In particular, they try to assess the ability of different factors (rain, earthquakes) to trigger events using very simple models.

In order to reach publication standard, this paper must be improved:

11) Many descriptions of geohazard chains can be found in the literature, including chains initiated under strong earthquake. Thus, it is unclear to me how this paper brings originality and/or novelty in this peculiar scientific field.

22) From a general viewpoint, the scientific content of the paper seems sound, although very simple models are used. However, the data is not always sufficiently described. For example, prior to plot the accumulated sliding, it is necessary to produce a table with the list of selected earthquakes and a figure and table indicating the estimated acceleration for each earthquake. Moreover, many figures lack accuracy and are of poor quality (see my comments below).

33) I strongly recommend reorganizing the article so that the intermediate calculation steps appear in the appendix.

The article contains a significant number of spelling mistakes and typos as well as sentences that are not grammatically correct. I indicate some of them in the comments section, although there are so many that I couldn't list them all.

COMMENTS

·     Lines 19-20: “providing a reference  for  disaster prevention and reduction in strong earthquake areas by analyzing the accumulative sliding  amount  and  the  critical  rainfall  of  debris  flow  formed  by  loose  deposits.” àchange for “providing a reference  for  disaster prevention and risk reduction in strong earthquake areas by analyzing the accumulative sliding  amount  and  the  critical  rainfall  for  debris  flows  formed  by  loose  deposits.

·        Line 28: change “geatation” to gestation

·        Line 30: Change “silde” to slide

·  Lines 41-42: specify a magnitude range for “moderate and strong earthquakes”, quantify what is “frequent” and give references for such observations. Add references for the report of “serious” “mountain disasters”.

·        Lines 42-43: Change “consentration” to concentration.

·        Line 57: “of of heavy rainfall” delete the repeated word.

·        Line 76: “developed”: why is this word underlined?

·     All the text: a space is often missing before the square brackets to make quotes. For example, this is the case at lines 50, 53 and 62 (“debris flows[1-6]”,”space range[7]”, “even longer[11-15]”)

·   Lines 81-83: Change “instability” to stability, “eathqauke” to earthquake, “appeared” to appear, “provided” to provide, and add a space before “[24,25].”

·        Line 92-95: “In was verified […] natural action.” This sentence is not grammatically correct.

·        Line 106: change “   to form debris flow” to “form debris flows”

·        Line 116: change “this paper analysed” to “this paper analyse”

·        Figure 1b: add the figure scale, a legend for the colour scale, indication for the location

·        Line 148: change “segnificant" to significant

·        Line 145: there is no correspondence between the geological description “Mesoproterozoic (Pt) and Triassic (T)”with the legend of the geological map in Figure 2. Add the description of the lithology.

·        Figure 3: the figure is missing a general map with the location of the 3 landslides. Also, add the figure scales and orientation. Produce images before and after landslide destabilizations.

·        Figure 4: the figure is missing a general map with the location of the photographs. Also, add orientation indications on the photos. Give the date of the photos.

·        Line 213: change “geohard” to geohazard

·        Line 221: “showing  a  chain  development  of  disastes  accosiated  with  landslides and debris flows.” Too many misspellings in this sentence!

·        Figure 5: prior to plot the accumulated sliding, produce a table with the list of selected earthquakes and a figure/table with the estimated acceleration for each earthquake

·        Line 281: “The  total  amount  of  loose  deposits  was  approximately   93.97×10 4 m 3 , and the strength of the deposits was high.” How did you estimate this volume? How can you justify that “the strength of the deposits was high”?

·        Line 294: Change “parger” to larger

·        Table 1: How do you estimate the landslide volumes?

·        Line 311: Change “typr” to type

·        Figure 7: axis titles should be in English!!

 

 

 

 

 

 

 

Author Response

Dear reviewers,

Thank you very much for your valuable comments on the paper with water-2143719. We have revised the paper in detail according to the reviewer’s comments, and please give valuable comments if there is any inappropriate.

The work of He et al. present the case study of a geohazard chain with landslide and subsequent debris flow that was initiated under strong earthquake. Despite the fact that available data is very scarce, authors manage to reconstruct the sequence of events of the geohazard chain. In particular, they try to assess the ability of different factors (rain, earthquakes) to trigger events using very simple models.

In order to reach publication standard, this paper must be improved:

11) Many descriptions of geohazard chains can be found in the literature, including chains initiated under strong earthquake. Thus, it is unclear to me how this paper brings originality and/or novelty in this peculiar scientific field.

Reply: At present, there are many articles on the initiation of disaster chain and geological disaster chain under the influence of strong earthquakes, but those papers mostly focus on describing some common characteristics of disaster chain in a large range, and the disaster mechanism and evolution characteristics of disaster chain of single gully under the influence of strong earthquakes are insufficient. Therefore, this paper expounds the disaster mechanism and evolution characteristics of disaster chain of Niumian gully. To identify the disaster mechanism and development law of disaster chain, and provide scientific basis for disaster prevention and reduction of landslide - debris flow disaster chain in strong earthquake area.

22) From a general viewpoint, the scientific content of the paper seems sound, although very simple models are used. However, the data is not always sufficiently described. For example, prior to plot the accumulated sliding, it is necessary to produce a table with the list of selected earthquakes and a figure and table indicating the estimated acceleration for each earthquake. Moreover, many figures lack accuracy and are of poor quality (see my comments below).

Reply: Before drawing the cumulative slide graph, it is necessary to generate a table containing the selected earthquake and the calculated earthquake acceleration, which was also considered in the writing, but the table was not added due to the limitation of space at that time. Now this problem has been modified and the table is added to the appendix. At the same time, the numbers in the text are checked to ensure their accuracy. Please refer to the revised edition.

33) I strongly recommend reorganizing the article so that the intermediate calculation steps appear in the appendix.

The article contains a significant number of spelling mistakes and typos as well as sentences that are not grammatically correct. I indicate some of them in the comments section, although there are so many that I couldn't list them all.

Reply: we reorganized the article according to the requirements, and the intermediate calculation steps have been put into the appendix. At the same time, in view of the large number of spelling mistakes in the article, we used the recommended relevant institutions for polishing, and attached a polishing certificate. Please refer to the revised version.

 

COMMENTS

• Lines 19-20:“providing a reference  for  disaster prevention and reduction in strong earthquake areas by analyzing the accumulative sliding  amount  and  the  critical  rainfall  of  debris  flow  formed  by  loose  deposits.” àchange for “providing a reference  for  disaster prevention and risk reduction in strong earthquake areas by analyzing the accumulative sliding  amount  and  the  critical  rainfall  for  debris  flows  formed  by  loose  deposits.

Reply: these sentences have been revised, please refer to the revised edition.

• Line 28: change “geatation” to gestation

Reply: geatation has been replaced by gestation, please refer to the revised edition.

• Line 30: Change “silde” to slide

Reply: we have changed silde to slide, please refer to the revised edition.

• Lines 41-42: specify a magnitude range for “moderate and strong earthquakes”, quantify what is “frequent” and give references for such observations. Add references for the report of “serious” “mountain disasters”.

Reply: Generally speaking, a moderate earthquake refers to the earthquake with a magnitude greater than 4.5 and less than 6, while a strong earthquake mainly refers to the earthquake with a magnitude of more than 6. At the same time, relevant references have been added in the revised manuscript.

• Lines 42-43:Change “consentration” to concentration.

Reply: we have changed consentration to concentration, please refer to the revised edition.

• Line 57: “of of heavy rainfall” delete the repeated word.

Reply: the repeated word “of” has been deleted, please refer to the revised edition.

• Line 76: “developed”: why is this word underlined?

Reply: At the time of writing, perhaps due to a preservation problem or at that time accidentally pressed, which resulted in the development of the underline, the underline has been removed. please refer to the revised edition.

•  All the text: a space is often missing before the square brackets to make quotes. For example, this is the case at lines 50, 53 and 62 (“debris flows[1-6]”,”space range[7]”, “even longer[11-15]”)

Reply: We have carefully checked the format of all references and revised the references in detail.

• Lines 81-83: Change “instability” to stability, “eathqauke” to earthquake, “appeared” to appear, “provided” to provide, and add a space before “[24,25].”

Reply: It has been carefully revised according to the review comments, please refer to the revised edition.

• Line 92-95: “In was verified […] natural action.” This sentence is not grammatically correct.

Reply: At present, the article has been polished and the grammatical errors have been corrected. please refer to the revised edition.

• Line 106: change “   to form debris flow” to “form debris flows”

Reply: It has been carefully revised according to the review comments, please refer to the revised edition.

• Line 116: change “this paper analysed” to “this paper analyse”

Reply: It has been carefully revised according to the review comments, please refer to the revised edition.

• Figure 1b: add the figure scale, a legend for the colour scale, indication for the location

Reply: Figure 1b has been modified and related details has been added, please refer to the revised edition.

• Line 148: change “segnificant" to significant

Reply: It has been carefully revised according to the review comments, please refer to the revised edition.

• Line 145: there is no correspondence between the geological description “Mesoproterozoic (Pt) and Triassic (T)”with the legend of the geological map in Figure 2. Add the description of the lithology.

Reply: Substrata and lithology information have been added to Figure 2, please refer to the revised edition.

• Figure 3: the figure is missing a general map with the location of the 3 landslides. Also, add the figure scales and orientation. Produce images before and after landslide destabilizations.

Reply: The landslide location map has been added (see Figure 1c). However, since it is difficult to obtain the landslide photos before the Wenchuan earthquake in 2008, no pre-landslide photos have been added here.  please refer to the revised edition.

• Figure 4:the figure is missing a general map with the location of the photographs. Also, add orientation indications on the photos. Give the date of the photos.

Reply: The figure has been modified and the date of the photo has been added, Please refer to the revised edition.

• Line 213:change “geohard” to geohazard

Reply: geohard has been replaced by geohazard, Please refer to the revised edition.

• Line 221:“showing  a  chain  development  of  disastes  accosiated  with  landslides and debris flows.” Too many misspellings in this sentence!

Reply: the article has been polished, the relevant grammar and spelling errors have been corrected.

• Figure 5:prior to plot the accumulated sliding, produce a table with the list of selected earthquakes and a figure/table with the estimated acceleration for each earthquake

Reply: The table has been added to the appendix because it is too long, Please refer to the revised edition.

• Line 281:“The  total  amount  of  loose  deposits  was  approximately   93.97×10 4 m 3 , and the strength of the deposits was high.” How did you estimate this volume? How can you justify that “the strength of the deposits was high”?

Reply: The estimation of the loose deposits in the gully before the Wenchuan earthquake is mainly obtained through the analysis of the terrain before and after the earthquake and the field investigations, and it is described in the Emergency Investigation Report of the Niumiangou Debris Flow in the earthquake source Reserve of Yingxiu Town, Wenchuan County and the analysis of the dynamic change characteristics of the Niuzhuangou debris flow in the Wenchuan earthquake area by remote sensing.

• Line 294: Change “parger” to larger

Reply: parger has been replaced by larger, Please refer to the revised edition.

• Table 1: How do you estimate the landslide volumes?

Reply: The estimation of landslide volumes are mainly obtained from the remote sensing data before and after the earthquake, field visit and field investigation, and the Emergency Investigation Report of the mudslide in Niumianggou, earthquake source Reserve, Yingxiu Town, Wenchuan County.

• Line 311:Change “typr” to type

Reply: typr has been replaced by type, Please refer to the revised edition.

• Figure 7: axis titles should be in English!!

Reply: The picture has been modified, Please refer to the revised edition.

Reviewer 2 Report

The 12 May 2008 Wenchuan earthquake (M_s = 8.0) triggered a large number of landslides (rock avalanches???), resulting in loose unconsolidated material deposited along the mountain slopes and valleys. The authors study the landslides triggered in Niumian gully; the loose deposits from these landslides led to the damming of a river. The loose deposits also served as the source material for debris flows when subsequent rainfall caused a breaching of the dammed river and triggered floods and debris flows in the region. These landslides and debris flows have caused instability in a region that was stable before the 2008 Wenchuan earthquake. The authors use existing models to show that the magnitude of the Wenchuan earthquake was sufficient to generate landslides in the Niumian gully region; the authors also compute the critical rainfall that is needed to trigger debris flows of the loose unconsolidated deposits.

General remarks

(1)   The manuscript must be condensed. There is a lot of unnecessary information and repetition. Please delete sentences that are not pertinent to the work.

(2)    Other researchers have described how the 2008 Wenchuan earthquake triggered landslides, which in turn led to debris flows.
(e.g.  Zhang, Yong-Shuang, Yu-Liang Cheng, Xin Yao, Jun Wang, Shu-Ren Wu, and Meng Wang. "The evolution process of Wenchuan earthquake-landslide-debris flow geohazard chain." Geological bulletin of China 32, no. 12 (2013): 1900-1910.
Ni, Huayong, Chuan Tang, Wanmo Zheng, Ruge Xu, Kai Tian, and Wei Xu. "An overview of formation mechanism and disaster characteristics of post‐seismic debris flows triggered by subsequent rainstorms in Wenchuan earthquake extremely stricken areas." Acta Geologica Sinica‐English Edition 88, no. 4 (2014): 1310-1328.)

Researchers have also used physically-based models to study these processes.
(e.g. van den Bout, Bastian, Chenxiao Tang, Cees van Westen, and Victor Jetten. "Physically based modeling of co-seismic landslide, debris flow, and flood cascade." Natural Hazards and Earth System Sciences 22, no. 10 (2022): 3183-3209.)

Could you please clearly state how your work advances the field?

(3)    The authors use existing models to compute the critical rainfall, etc. These models invariably have underlying assumptions. The authors should state these assumptions and explain how the models are valid in their study.

(4)    A debris flow is a type of landslide
(Varnes, David J. "Slope movement types and processes." Special report 176 (1978): 11–33

Hungr, Oldrich, Serge Leroueil, and Luciano Picarelli. "The Varnes classification of landslide types, an update." Landslides 11 (2014): 167–194).

 So rather than speak of a landslide–debris flow geohazard chain, it would better if you specify the first type of landslide in this sequence (was it a debris slide, rock fall, rock slide, rock avalanche, etc.)

(5)    The authors use some non-standard terms, such as “sensible radius” (this term is used only in 28 other publications). Please use standard terminology.

 

(6)    The Related Work section should be rewritten in a way that frames the authors’ work in the context of the previous work done in this area and compares the authors’ work with that work, instead of only summarizing the previous work.

 (7)    The authors write 104 instead of 10^4, 106 instead of 10^6, etc. Please revise.

(8)    There are a lot of other typographical and spelling errors. I have marked a few in the attached PDF. Please have the manuscript proofread.

(9)    The writing should be improved. Please have the manuscript proofread by an English expert before resubmission.

(10) More comments in the attached pdf.

 

 

Comments for author File: Comments.pdf

Author Response

Dear reviewers,

Thank you very much for your valuable comments on the paper with water-2143719. We have revised the paper in detail according to the reviewer’s comments, and please give valuable comments if there is any inappropriate.

The 12 May 2008 Wenchuan earthquake (M_s = 8.0) triggered a large number of landslides (rock avalanches???), resulting in loose unconsolidated material deposited along the mountain slopes and valleys. The authors study the landslides triggered in Niumian gully; the loose deposits from these landslides led to the damming of a river. The loose deposits also served as the source material for debris flows when subsequent rainfall caused a breaching of the dammed river and triggered floods and debris flows in the region. These landslides and debris flows have caused instability in a region that was stable before the 2008 Wenchuan earthquake. The authors use existing models to show that the magnitude of the Wenchuan earthquake was sufficient to generate landslides in the Niumian gully region; the authors also compute the critical rainfall that is needed to trigger debris flows of the loose unconsolidated deposits.

General remarks

(1)   The manuscript must be condensed. There is a lot of unnecessary information and repetition. Please delete sentences that are not pertinent to the work.

Reply: At present, the manuscript has been compressed, and irrelevant and repetitive content has been deleted, please refer to the revised manuscript.

(2)    Other researchers have described how the 2008 Wenchuan earthquake triggered landslides, which in turn led to debris flows.
(e.g.  Zhang, Yong-Shuang, Yu-Liang Cheng, Xin Yao, Jun Wang, Shu-Ren Wu, and Meng Wang. "The evolution process of Wenchuan earthquake-landslide-debris flow geohazard chain." Geological bulletin of China 32, no. 12 (2013): 1900-1910.
Ni, Huayong, Chuan Tang, Wanmo Zheng, Ruge Xu, Kai Tian, and Wei Xu. "An overview of formation mechanism and disaster characteristics of post‐seismic debris flows triggered by subsequent rainstorms in Wenchuan earthquake extremely stricken areas." Acta Geologica Sinica‐English Edition 88, no. 4 (2014): 1310-1328.)

Researchers have also used physically-based models to study these processes.
(e.g. van den Bout, Bastian, Chenxiao Tang, Cees van Westen, and Victor Jetten. "Physically based modeling of co-seismic landslide, debris flow, and flood cascade." Natural Hazards and Earth System Sciences 22, no. 10 (2022): 3183-3209.)

Could you please clearly state how your work advances the field?

Reply: According to the literature you listed, the author has made a careful study. Currently, there are many articles on Wenchuan earthquake triggering landslide and resulting debris flow, but most of these articles describe large-scale and regional disasters, and most of the papers focus on landslides, and the disaster mechanism and evolution characteristics of single gully disaster chain under the influence of strong earthquake are not described enough. This paper expounds the disaster mechanism and development law of the disaster chain of Niumiangou, which provides scientific basis for disaster prevention and reduction of landslide and debris flow disaster chain in strong earthquake area.

(3)    The authors use existing models to compute the critical rainfall, etc. These models invariably have underlying assumptions. The authors should state these assumptions and explain how the models are valid in their study.

Reply: The formula used in this paper comes from literature [54], which is a conjectural formula obtained by analyzing data with regression theory. In the regression analysis, the critical rainfall is presented in the form of a number as the dependent variable (Gamaqimei Gully in Tibet with the minimum critical rainfall and Luwang Gully in Ya 'an with the maximum critical rainfall in China are taken as the upper and lower limits. And the characteristic distribution law of critical rainfall between dozens of debris flow gullies is analyzed statistically, and a dimensionless number K in the 0-1 interval is quantified. The derived formula is applied with examples to verify its rationality. Frequency method is a simple model for debris flow prediction based on the statistical data of county meteorological stations and weather forecast. In this paper, the required data can be obtained according to the County Record of Yajiang County and the Emergency Survey Report of Niumianggou Debris Flow in earthquake source Reserve of Yingxiu Town, Wenchuan County, so it can be directly applied in this paper. As for the critical rainfall calculation method proposed by He Siming, the critical rainfall threshold pre-condition has been added.

 

(4)    A debris flow is a type of landslide
(Varnes, David J. "Slope movement types and processes." Special report 176 (1978): 11–33

Hungr, Oldrich, Serge Leroueil, and Luciano Picarelli. "The Varnes classification of landslide types, an update." Landslides 11 (2014): 167–194).

 So rather than speak of a landslide–debris flow geohazard chain, it would better if you specify the first type of landslide in this sequence (was it a debris slide, rock fall, rock slide, rock avalanche, etc.)

Reply: Zhang Yongshuang, CHENG Yuliang, YAO Xin, et al. Formation and evolution of earthquake-landslide-debris flow disaster chain in Wenchuan, Sichuan Province [J]. Geological Bulletin of China, 2013, 26 (4) : 139-135. 32(12):11. "and" Emergency Investigation Report of Niumiangou Debris Flow in Earthquake Focal Reserve of Yingxiu Town, Wenchuan County ". from these two literatures It can be seen that the formation of Niumiangou landslide includes many types, such as plane slip, rockfall, slope deformation and so on. Loose accumulation bodies with large reserves, low compactness and mixed size of blocks are also formed on gully slopes, which are easy to start under the action of heavy rainfall and converge along steep gullies, accelerating the formation of destructive debris flow. Meanwhile, landslides not only provide source materials for the initiation of debris flow, but also block the gullies and form a barrier dam, which amplifies the scale of debris flow when the barrier dam breaks. Therefore, the landslide type is not specified in this article.

(5)    The authors use some non-standard terms, such as “sensible radius” (this term is used only in 28 other publications). Please use standard terminology.

Reply: By referring to relevant literature "Wang Suyun, Shi Zhenliang. The relationship between sensing radius and earthquake magnitude and its application [J]. Journal of Seismic Regionalization in China. Beijing: Seismological Press, 1993:179-184. "and" Lei Jiancheng, Gao Mengtan, Yu Yanxiang. Statistical research on epicentral intensity and sensible radius of modern earthquakes in Southwest China [J]. Earthquake Prevention Technology, 2006, 1(2): 137-145. ", changed to "Sensible Radius"

 (6)    The Related Work section should be rewritten in a way that frames the authors’ work in the context of the previous work done in this area and compares the authors’ work with that work, instead of only summarizing the previous work.

Reply: this part has been rewritten and modified, please refer to the revised manuscript.

 (7)    The authors write 104 instead of 10^4, 106 instead of 10^6, etc. Please revise.

Reply: these errors have been corrected, please refer to the revised manuscript.

(8)    There are a lot of other typographical and spelling errors. I have marked a few in the attached PDF. Please have the manuscript proofread.

Reply: The full text of the article has been polished, please refer to the revised manuscript.

(9)    The writing should be improved. Please have the manuscript proofread by an English expert before resubmission.

Reply: The full text of the article has been polished, please refer to the revised manuscript.

(10) More comments in the attached pdf.

The following comments comes from PDF version

• Lines 19: Please explain how you used remote sensing data in your work

Reply: The application of remote sensing data is mainly used to determine the topographic conditions before and after the earthquake, and obtain the provenance of the study area by combining field investigation and literature report.

• Lines 28: gestation?

Reply: it has been corrected, please refer to the revised manuscript.

• Lines 65: The word, "different countries" is used, but most, if not all, references are from Chinese authors.

Reply: This section has been revised and the references updated, please refer to the revised manuscript.

 Lines 66-68:Since this research is closely linked to yours, you can write a little more, e.g. state the results of the paper

Reply: This part of the content has been added, please refer to the revised manuscript.

• Lines 68- 80:Not sure how this research relates to the work described in this paper

Reply: This part has been rewritten because it is not clearly expressed and is disconnected from the article, please refer to the revised manuscript.

• Lines82:earthquake; check spelling

 Reply: The full text of the article has been polished, please refer to the revised manuscript.

6) Lines86-87:can state the results of this work. The literature review section should not just state work done by others. The work should have a bearing on the current paper and the literature review section should highlight the relevance of the cited work to the current study

Reply: This part has been rewritten, please refer to the revised manuscript.

7) Lines110-112:Please see van den Bout, Bastian, et al. "Physically based modeling of co-seismic landslide, debris flow, and flood cascade." Natural Hazards and Earth System Sciences 22.10 (2022): 3183-3209.

Reply: According to the recommended literature, this part has been modified, please refer to the revised manuscript.

• Lines128:Do you mean "first-order tributary"?

Reply: The Niumian Gully is the first-tributary on the right bank of the Minjiang River.

• Lines129:I think the word "gully" is a better choice than the word "ditch".

Reply: thanks for your careful work, yes , it should be gully.

• Lines177:It would be good to provide even an approximate date of these landslide occurrences. Reply: The date of the photo has been added.
• Lines184:6 should be a superscript、Generally (misspelt in original)

Reply: this has been corrected, please refer to the revised manuscript.

• Lines213:What is written in this subsection has already been discussed earlier in the paper

Reply: The duplicates in the article have been deleted, please refer to the revised manuscript.

• Lines228:A Google Scholar search for "sensible radius" earthquake yields only 28 results. Is the term "sensible radius" commonly used in earthquake studies? Please check if the term you need is the Joyner-Boore distance (the shortest distance from the site to the surface projection of the rupture surface).

Reply: By referring to relevant literature "Wang Suyun, Shi Zhenliang. The relationship between sensing radius and earthquake magnitude and its application [J]. Journal of Seismic Regionalization in China. Beijing: Seismological Press, 1993:179-184. "and" Lei Jiancheng, Gao Mengtan, Yu Yanxiang. Statistical research on epicentral intensity and sensible radius of modern earthquakes in Southwest China [J]. Earthquake Prevention Technology, 2006, 1(2): 137-145. ", changed to "Sensible Radius"

• Lines231:The equality sign is present in both instances. Please correct this.

Reply: Due to the careless error in writing, it has been changed, and the full text has been checked to avoid similar situation.

• Lines260:Is it M_s, or M_w?

Reply: it is Ms, please refer to the revised manuscript.

• Lines27:please rephrase; it is difficult to understand

Reply: Since this paragraph is not very strong with the relevant lines of the article, I feel that this paragraph is verbose, so I have deleted this paragraph to make the article more compact, please refer to the revised manuscript.

• Lines280:infrequent??

Reply: According to the investigation, there was no debris flow disaster in the study area before the 5.12 Wenchuan earthquake, and the development of adverse geological phenomena such as landslide and landslide in the basin was relatively weak, which was due to the improper wording in translation.

• Lines283、288、291、294:served? become?Use an en-dash (–) instead of a tilde (~).larger Reply: this has been corrected, please refer to the revised manuscript.
• Lines306:Please check the placement of the row border separating Landslide H02 and Landslide H03.

Reply: The boundary of H02 and H03 has been checked and corrected, please refer to the revised manuscript.

• Lines311:type

Reply: it has been changed to type, please refer to the revised manuscript.

• Lines319:These models would have certain assumptions. This paper does not discuss the assumptions underlying the models used and how applicable the models are for the situation discussed in this paper

Reply: As the literature quoted in this paper is a hydrological level model in loose deposits established according to the infinite slope theory, which needs to meet the basic assumptions of the infinite slope theory and Darcy's law, and is limited by the space condition, it is not indicated in the paper before, but has been explained in the paper now, please refer to the revised manuscript.

• Lines326:not meter-squared, meter-cubed

Reply: this has been corrected, please refer to the revised manuscript.

• Lines328:Where did you get this equation? Is it from [54]? If so, please state this. Also, please state all the assumptions that go into this model, and mention how well your study site fits the assumptions.

Reply: The formula used in this paper comes from literature [54], which is a conjectural formula obtained by analyzing data with regression theory. In the regression analysis, the critical rainfall is presented in the form of a number as the dependent variable (Gamaqimei Gully in Tibet with the minimum critical rainfall and Luwang Gully in Ya 'an with the maximum critical rainfall in China are taken as the upper and lower limits. And the characteristic distribution law of critical rainfall between dozens of debris flow gullies is analyzed statistically, and a dimensionless number K in the 0-1 interval is quantified. The derived formula is applied with examples to verify its rationality. Frequency method is a simple model for debris flow prediction based on the statistical data of county meteorological stations and weather forecast. In this paper, the required data can be obtained according to the County Record of Yajiang County and the Emergency Survey Report of Niumianggou Debris Flow in earthquake source Reserve of Yingxiu Town, Wenchuan County, so it can be directly applied in this paper. As for the critical rainfall calculation method proposed by He Siming, the critical rainfall threshold pre-condition has been added.

• Lines332:Please explain the difference between Extremely high frequency and High frequency

Reply: According to literature 54, high frequency refers to one or two to several times of debris flow occurring in a year, and very high frequency refers to several to a dozen times of debris flow occurring in a year. The definition of high frequency and extremely high frequency is fuzzy, but I think if a debris flow gully occurs only 20 or 30 times in a year, it is generally considered high frequency. If it occurs more times in a year, is extremely high frequency.

• Lines356:The axes and legends for the graphs are in Chinese!

Reply: the Figure has been modified, please refer to the revised manuscript.

• Lines359-360:Doesn't make sense to say that the critical rainfall ranged from 0 to ... Then even when there is no rainfall, the slope is in a critical state

 Reply: By referring to the literature, we know that RE refers to the 24-hour cumulative rainfall. When the 24-hour cumulative rainfall is 50mm, the calculated critical rainfall is 0-3mm, which proves that when the rainfall reaches 50mm, the slope is just in a critical state, and this rainfall is the lower limit of the calculated loose accumulation body, and the result is not much different from the formula proposed by He Siming. The two can verify each other to prove the correctness of the result.

• Lines513:Please check that all references are cited in the proper format.

Reply: we checked all of the references and corrected the format, in addition,the full text of the article has been polished, please refer to the revised manuscript.

 

 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The readability of the manuscript has greatly improved. The paper can be published after minor revisions (please see pdf for further comments).

Comments for author File: Comments.pdf

Author Response

Dear reviewer, thank you very much for your valuable comments on the article, which have greatly improved the quality of the article. We have revised the full text according to the comments in the PDF file, please see the revised manuscript for details. Thank you very much for your patience and hard work.