Rainfall Warning Model for Rainfall-Triggered Channelized Debris Flow Based on Physical Model Test—A Case Study of Laomao Mountain Debris Flow in Dalian City
Round 1
Reviewer 1 Report
The paper has been successfully improved comparing to the former version (water 1136262). In fact, at the present stage the paper has been drastically reorganized, and at the present stage it results well organized and balanced among the different sections.
Even though I don’t feel adequate to judge about English language and grammar, it seems to me the Abstract’s punctuation must be revised, as much as through the whole text, since it results sometime confusing.
Author Response
The paper has been successfully improved comparing to the former version (water 1136262). In fact, at the present stage the paper has been drastically reorganized, and at the present stage it results well organized and balanced among the different sections.
Even though I don’t feel adequate to judge about English language and grammar, it seems to me the Abstract’s punctuation must be revised, as much as through the whole text, since it results sometime confusing.
Response: Thank you very much for your careful check and your affirmation of my modification for the article. We gratefully appreciate for your valuable suggestion. The misused punctuation in Abstract’s lines 13-15 has been corrected.
Reviewer 2 Report
I think that the authors made a good effort to adjust and rearrange the work. I think that it could be accepted after minor revision. In the following, I report some last comments.
line 326, eq 8: what is t?
line 620: equation numbers restart from (8). This equation should be the number (17). In the same way, you should renumber the following equations.
line 662: D is not in the formula, you should explain what M is.
line 685: which equations (10) and (11)? Renumbering.
line 745: Reformulate the caption including the meaning of AMR and PCR.
lines 755-768: the sentence "Accordingly, the debris flow rainfall thresholds calculated using the IPM, IPD and HIMM models had certain accuracy and reliability in the Laomao Mountain area.", and the following paragraph are a bit "strong". I think that these statements are a bit rushed with a so small sample.
Author Response
I think that the authors made a good effort to adjust and rearrange the work. I think that it could be accepted after minor revision. In the following, I report some last comments.
Point 1: line 326, eq 8: what is t?
Response 1: The definition of t in the equation (8) is supplemented in lines 328-329 of the article.
Point 2: line 620: equation numbers restart from (8). This equation should be the number (17). In the same way, you should renumber the following equations.
Response 2: Thank you very much for your careful check. All the equation numbers in this paper have been checked and modified.
Point 3: line 662: D is not in the formula, you should explain what M is.
Response 3: We delete the definition of D and add the definition of M in lines 661-662.
Point 4: line 685: which equations (10) and (11)? Renumbering.
Response 4: Thank you very much for your careful check. All the equation numbers in this paper have been checked and modified.
Point 5: line 745: Reformulate the caption including the meaning of AMR and PCR.
Response 5: Based on your suggestion, we change the caption to "Validation of critical rainfall prediction results".
Point 6: lines 755-768: the sentence "Accordingly, the debris flow rainfall thresholds calculated using the IPM, IPD and HIMM models had certain accuracy and reliability in the Laomao Mountain area.", and the following paragraph are a bit "strong". I think that these statements are a bit rushed with a so small sample.
Response 6: The sentence "Accordingly, the debris flow rainfall thresholds calculated using the IPM, IPD and HIMM models had certain accuracy and reliability in the Laomao Mountain area." has been deleted.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
I appreciate the effort that the authors did to improve the readability of this work. English sounds almost perfect to me. Unfortunately, this work maintains most of the lacks already highlighted by my colleagues that reviewed this paper in the previous submission.
Just to give some examples:
- how is material related to the Laomao Mountain debris flow? The material used in the experiment was taken n that area but there are no characteristics in the study related to that debris flow.
- debris flow initiation involves a flowing process that in the study is not considered
- Table 4: the shown calculations need a little bit more explanation; how rainstorm, heavy rainstorm, extraordinary rainstorm, rare extraordinary rainstorm are related to return period?
The list could go on and on. I think that this paper will be taken into account for publication once all the previous suggestions will be evaluated. I ask the authors to do so.
Reviewer 2 Report
Manuscript ID: water-1136262
Type of manuscript: Article
Title: Rainfall Warning Model for Rainfall-triggered Channelized Debris Flow based on Physical Model Test — A case study of Laomao Mountain Debris Flow in Dalian City
Authors: Yuzheng Wang, Lei Nie, Chang Liu, Min Zhang, Yan Xu, Yuhang Teng, Chonghao Bao, Yuanyuan He, Fansheng Kong, XiangJian Rui, Tao Zhang, Chao Du, Lihaolin Jin, Zhengguo Li
Overview
On the one hand, some contents of the manuscript have been described with particular detail, sometimes very extensive descriptions are provided (for instance about the tests on the debris flow initiation, i.e., Sections 4.1-4.3); on the other hand, details lack for other contents (for instance about the relationship between rainfall and debris flow initiation, in particular the datasets used to estimate the ID relationships, i.e., Sections 4.4 and 4.7).
Therefore, clarifications need in order to have a full comprehension of the proposed study.
My opinion is that the actual form of the present study needs major revision before the publication in Water.
Broad comments
1) Just one case study has been used to test the accuracy of the prediction. Have the critical thresholds been estimated by considering also the rainfall observed for the case study event in the calibration dataset? The overfitting issue may arise in this case.. Roughly summarizing, it seems that a model fitting has been described for the tested rainfall intensity-duration relationships. Is this guess right or wrong? No false alarms seem to be produced, just one event is observed: have authors tried to split the available dataset in calibration and validation sub-samples?
2) Results in Section 4.7 are just described. Explanations about the reasons for obtained outcomes should be added, trying to justify the differences.
Specific comments
Pag.1: “the critical rainfall values that induce debris flows on the basis of existing data” The term “existing data” is generic. Please, briefly describe the dataset available.
Pag.1: The acronym IPD and IPM should be made explicit.
Pag.1: References should be added about the exponential 2D and extreme cum models in Section 4.5.
Pag.1: “The comparison results showed that the new multi-parameter debris flow initiation warning models of IPD and IPM can effectively modify the traditional intensity–duration model and have certain reli-ability and practical values. They can provide an effectual scientific basis for future work on the prevention and control of debris flow disasters.”
It should be added that the statement is supported by an analysis based on just one observed event exceeding the triggering threshold.
Pag.2: “From July 26 to 28, 1981, under the influence of typhoon “8108” and the westerly trough, the Laomao Mountain area in the north of Wafangdian and Pulandian, Dalian City, Liaoning Province suffered from heavy rainfall of 300–670 mm.”
A graph should be added with the hourly rainfall series for those three days.
Pag.3: “the annual average precipitation of the city in 2011 was 909.1 mm”
Did a debris flow not occur in this extreme year?
Why the year 2011 is not included in the statistics shown in Fig.4?
Pag.3: “and a multi-parameter debris flow initiation warning model that can comprehensively reflect the soil properties and geological conditions was proposed. Then, the critical rainfall inducing a debris flow was calculated using the relationship between rainfall and debris flow initiation obtained from the previous research on debris flow initiation mechanism.”
A brief description of the two methods should be here added.
Pag. 3: “20°–60° on both sides, as shown in Figure 2”
Figure 2 should be cited after Figure1. Otherwise, swap the number of the figures.
Pag. 4: “a debris flow can easily break out in case of heavy rainfall”.
This statement seems to contrast the fact that just one event is discussed in the manuscript.
Pag. 5: The filling of the first column in Table 1 is wrongly formatted (the amplitude of the cell should be enlarged in order to have the name of the gully on just one row)
Pag. 7: “probe WC 2-1”.
The acronym should be made explicit.
Pag. 9: “storm rainfall values were calculated by conducting basin point estimation first and point surface discount calculation afterward”.
The meaning of this sentence is not clear. What do author mean with “point surface discount”?
Pag. 9: “and then the design rainfall (Htp) and modeled rainfall intensity (MRI) under 1h calendar time were estimated”.
Details should be added about how Htp and MRI were estimated.
Pag. 9: “The rain types corresponding to each particle gradation were persistent rainstorm, persistent extraordinary rainstorm, rain-storm to extraordinary rainstorm, and persistent rare extraordinary rainstorm.”
The four rain types should be identified quantitatively.
Pag. 9: “Six sets of typical tests with different particle gradations and rain intensities were taken out”.
Details should be added about the criterion used to take out the selected six typical tests.
Pag.18: “and Equation # can fit different curves by changing parameters”
Is “#” the right character?
Pag. 21: “the 1-h rainfall threshold is 22.56mm”.
Is this rainfall intensity value comparable with the PCR value shown in Table 8? Why is this value about just a quarter of PCR values shown in Table 8? How is the value of 22.56 computed?
Pag. 21: “a multi-parameter critical rainfall combination discriminant was established to provide a new idea for constructing a reasonable multi-threshold model of debris flows”.
Are the proposed methods novel approaches originally developed by authors? Please specify; otherwise, add specific references.
Pag. 22: “The rainfall intensity was set as the dependent variable in the fitting of the IPD model to select a suitable regression model and achieve an enhanced fit.”
This sentence is not clear. Is this content valid just for IPD? If yes, please specify the reasons.
Pag. 24: “including indirect and direct pre-rainfall [50]”
Please, briefly recall the definition of the two types of rainfall.
Pag. 24: “Where:??( 1,2,3,…n) is the daily rainfall (mm) of n days before the debris flow out-break”
Is ?? right? Or should ??0 right?
Pag. 25: “The critical rainfall prediction results of the debris flow gully in the Laomao Mountain area were calculated, as shown in Table 6.”
Please clarify which dataset has been used to compute these critical rainfalls.
Pag. 25: “The prediction results of the IPM model were generally larger than those of the IPD model. The intensities of rainfall that might induce debris flows in the main gullies of Dongmatun, Matun, and Heping predicted using the IPM model were greater than those predicted using the IPD model. By contrast, the intensities of rainfall that might induce debris flows in the main gullies of Zhangjiacun and Taiyang predicted using the IPM model were less than those predicted using the IPD model.”
The Zhuanshan case is not cited in this comparison.
Pag.25: “The prediction results of both models showed that the rainfall intensity that might induce a debris flow in the main gully of Matun was smallest with the highest susceptibility; the rainfall intensities that might induce debris flows in Dongmatun, Zhangjiacun, and Heping were closer with the second highest susceptibility; the rainfall intensities that might induce debris flows in Zhuanshan and Taiyang were largest with the lowest susceptibility.”
What do author mean with “susceptibility”?
Pag. 25: “The prediction results of critical rainfall in the debris flow gully of the Laomao Mountain area are shown in Table 7.”
Please clarify which dataset has been used to compute these critical rainfalls.
Pag. 25: “In accordance with the rainfall data from 1981 to 2015 from the three regional moni-toring stations”.
Why is this period different with respect to statistics shown in Fig.4?
Pag. 25: “the annual 1 h maximum rainfall (AMR)”.
Have authors considered the chance that a debris flow event could occur in case of a rainfall event is not the yearly maximum rainfall (for instance in case of high soil saturation due to precipitation during the previous days/weeks)?
Pag. 27: “In comparison with the 1 h maximum rainfall data of each year, when the 1 h maximum rainfall of the year was larger than the predicted rainfall threshold of debris flows obtained using the two methods, a debris flow would occur, such as the debris flow that occurred in 1981; when the 1 h maximum rainfall of the year was smaller than the predicted rainfall thresh-old of debris flows obtained using the two methods, no debris flow occurred.”
Why do author cite just two methods in this comment? Do they not consider the HIMM? But, all the three approaches are mentioned in the following sentence.
Pag. 27: “the IPM and IPD models and the calculation method of the initiation mechanism”.
Please consider to use “HIMM” instead of “calculation method”, in order to avoid misunderstanding with the “calculation results” terms following few rows under.
Pag. 27: “The minimum value in the calculation results was adopted as the debris flow rainfall threshold.”
Do authors mean the minimum value among IPM, IPD and HIMM?
Pag. 27: “A debris flow oc-curred when the historical rainfall was larger than the calculation results, no debris flow occurred when it was smaller than the calculation results, and no missed alarm would occur. Therefore, the warning models proposed in this paper have certain safety.”
Authors should mention that just one event occurred in the considered period.
Pag. 28: “but significant differences exist among certain data, such as the rainfall threshold calculation results of Taiyang.”
This statement is not fully right, given that the differences for other two sites are similar to those of Taiyang (i.e., Zhangjiacun and Zhuanshan). Please, reformulate it.
Pag. 28: “the contingency of experimental data cannot be completely avoided”
What do authors mean with “contingency”?
Pag. 29: “and corrected the deficiency of the traditional ID rainfall threshold model,”
Which outcomes support this statement? Could the value of 22.56 (the traditional ID rainfall) be added as term of comparison in Table 8? Or is this last mentioned value not comparable, due to a different dataset used to compute it with respect to the other three PCR values?
Reviewer 3 Report
The authors present a series of laboratory experiments on artificial slope instability under artificial rainfall. The experiments are interesting and of one important topic of landslide modeling. To enhance the validity of this manuscript, there are two main concerns regarding the experiments:
- Please supplement the verification of uniformity of the artificial rainfall.
- In figures 8 and others, it seems there is a smooth impermeable sheet at the bottom of soil layer. This smooth sheet will dominate the failure of soil layer, but it is not usually consistent with the real field condition. So, the authors are suggested to verify this experiment configuration. Also, the experiment results in Figures 7 to 13 should be compiled into fewer figures with appropriate annotations.
Besides, here provides two minor suggestions:
- Figures 1 and 2 can be compiled into one figure consisting of the aerial photo with longitudes and latitudes as well as the profile of the cross section EE’.
- Figure 4, the variability of monthly-averaged rainfall should be supplemented to enhance the rainfall effects in each month within one year.
Reviewer 4 Report
At the present stage the paper seems too long, and not well organized.
Figures are of poor quality (caption not always adequate to describe the content of the plots and most of the axis legends are unreadable) and tables are not always adequately commented in the text.
The experimental section and model presentation are included in the same paragraph (i.e. §4) inducing confusion in the reader.
The experimental activity (§4.1-4.3) has been described sometime too widely, and the most relevant points are not adequately put in evidence, generating confusion in the reader.
The section of the paper devoted to the model presentation (§ 4.5-4.7) results confused, even because of missing definition and double-numbered equations.
