The Trend in the Risk of Flash Flood Hazards with Regional Development in the Guanshan River Basin, China
Round 1
Reviewer 1 Report
The manuscript "The Risk Trent of Flash Flood Hazard with the Regional Development in Guanshan River Basin, China" by Chen et al investigates the change in risk due to flooding across three periods using a mixture of hydrological and hydrodynamic modelling. I believe this manuscript is suitable for this journal and would be of interest to the scientific committee.
However, I have a number of comments I feel should be addressed:
Major comments:
- The methodology is not clear enough. More information is needed on the TOPMODEL and FLO-2D modelling. There is no need to mention other hydrological models not used in the study. What are the forcing data for the TOPMODEL? Is the topographic index derived using the high resolution DEM created or ASTER, which is only mentioned at the end of the manuscript. More information is needed on the FLO-2D model too. Is this a full 2-D model or a 1-D/2-D model. Does it use the full shallow water equations? Is it a flexible or fixed grid? How are the TOPMODEL outputs used in the FLO-2D model. What are the extent of the FLO-2D domain? How was the river bathymetry found?
- Lines 185-189: Please ensure parameters are consistent throughout paragraph and with equation. If a represents the first year (earlier period) and b represents the second year (later period) why are you dividing by b? I would assume you divide by the a to get the percentage change. Please double check all Increased Ratio calculations.
- I found it hard to follow the results section. Why were design storms calculated, yet outputs from a TOPMODEL simulation were used to force the FLO-2D model. With the TOPMODEL calibration why was coefficient of determination used and not a more widely accepted objective function used, such as NSE, or KGE or even RMSE. Coefficient of determination may result in a "good fit" but there maybe large biases. How was the FLO-2D model calibrated. What are the friction values for river and floodplain? Do these vary with landuse?
Minor:
- Line 86/89: Please quantify "serious" and "devastatingly".
- Table 1: How are Disaster degree determined? Are these related to Hazard Level in table 7.
- Lines 90-94: This paragraph is very difficult to follow. I suggest the author re-structure this paragraph to more clearly state the point of the "accident points"
- Line 104 and 1007: What interpolation methods were used?
- Section 2.2. What are the error characteristics of the 10 m DEM? This is very important to judge the quality of the FLO-2D model outputs. Especially the results shown in Table 4.
- Line 152: Define what is meant by "reliable".
- Figure 3. Very difficult to read legend.
- Figure 4: Difficult to read legend.
- Table 6: It would be good to include areas too. This would make understanding Table 7 easier for the reader.
- Line 331: I suggest you rephrase "probability of casualties". Casualties are not only as a results or a hazard but vulnerability plays a major role too.
- Line 336: Define "more livable".
- Line 362-367: Both ASTER and SRTM are mentioned here for the first time. Were either used in the study? I also found it difficult to understand the message in this paragraph.
- Line 416-417. It would be worthwhile for the authors to comment why RSAF can be referred to help humans avoid the risk of flash flooding, instead of the typical flood hazards maps that are used worldwide. And if RSAF is superior to flood hazard maps, why is that the case?
Author Response
Dear Reviewer,
We appreciate for your careful reading and helpful comments. Those comments are very valuable and constructive for revising and improving our paper, as well as the significance of our research. We have addressed the points noted below. You will find our general reply and point-by-point responses in the attachment.Thank you very much.
Sincerely Yours,
Ningyue Chen
Dept. of Hydrology and Water Resources, Wuhan University, China
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear Authors,
The article The Risk Trend of Flash Flood Hazard with the Regional Development in Guanshan River Basin, China (ID: water-821129) is presenting the use RSAF in order to quantify the hazard posed by flash floods in Guanshan River, China. The English of the manuscript needs to be reviewed by a native English speaker because at some points it is hard to follow what the authors are trying to say.
At this stage, I recommend a thorough Major Revision, because there are some more things to be considered and which are mentioned below:
The Introduction section offers some examples of methodological aspects related to quantifying the hazard posed by flash floods. As flash floods are a real threat since the Prehistory and it is known that humans located their settlements in the floodable areas (e.g. Nile and not only), it would be nice to write a bit about that as well. As your Introduction section is too short and does not offer a proper overview of the matter. Also, offer some examples of studies referring to flash floods from different parts of the Globe and/or from different climatic areas (there is plenty of literature out there to do that). This section needs a thorough update and review.
L13: replace “construct” with “develop”
L14-19: this sentence is too long. Try breaking it up into 2 or 3 smaller sentences. Also, please write what TOPMODEL, FLO-2D, and RSAF stands for
L19: “…disasters in human…” or “…disasters affecting human…”?
L23-24: “from 2013 to 2018….on August 5, 2012”….makes no sense. Please, correct
L72: please put “m a.s.l.”
Figure 1: please put a bigger map with China in which you show the location of Hubei Province (not everybody knows where it is). Use map grids (preferably WGS84 coordinates) for all maps, especially for the one in which you have the DEM of the study area. Referring to scale, put it in km and not in meters (as it has too many numbers). Delete the word Legend, it is obvious that it is a legend. Include in the legend the altitude and the colour scale.
L78: there is a comma after “Provinces”
L79: correct is “floods” or “flood events”
L81-82: rephrase this sentence
L84: you sure is “28 hours” or 24?
L86: “of highway”
L88: please, put the economic losses in USD and/or EUR
If you have some photos of the destroyed houses, roads from the flood, please, include them in your article; or some media online websites.
L89: leave this row empty
L90: “disaster that happened…”
L102-108: I am confused. What resolution do you DEM have? 0.1 or 10 m? please, specify
L110: please, put reference for that
L124: please, add references
L121: please, include a methodological flowchart. That would be of very much use so that the reader can better understand what you are trying to explain, and the steps taken
L145-154: this should be in the Introduction section
L180-181: please, put the amounts in USD and/or EUR
L187: a and b supposed to in italic
Figure 3 and 4: the Legend capture is too small (please, enlarge)
Figure 5 (see comments from Figure 1) (maybe you mean Low Risk for the green class)
Figure 8: please, add a DEM or a shaded relief map in the background for the 4 figures and differentiate them by adding (a, b, c, d)
References: please, comply with the style of the journal. Journal names are to be written in italic and abbreviated.
L454: why is the DOI written twice here?
Kind regards,
Good luck with the review.
Author Response
Dear Reviewer,
We appreciate for your careful reading and helpful comments. Those comments are very valuable and constructive for revising and improving our paper, as well as the significance of our research. We have addressed the points noted below. You will find our general reply and point-by-point responses in the attachment.Thank you very much.
Sincerely Yours,
Ningyue Chen
Dept. of Hydrology and Water Resources, Wuhan University, China
Author Response File: Author Response.pdf
Reviewer 3 Report
The title of this paper is “The Risk Trend of Flash Flood Hazard with the Regional Development in Guanshan River Basin, China”. Overall, the concept of this paper is very interesting. However, this paper should be modified for publication in Water. I recommend a minor revision in this paper because this study could be improved.
- In this paper, I recommend to replace the word “we” with “authors”.
- In line 64-65, the word “RASF” and “Increased Ratios” were used. Should these words be written in italics?
- In Section 2.2 (data), it is required to show the type of discharge and rainfall data.
- In Section 3.1(TOPMODEL), the description of the model is insufficient.
- In Section 3.2(FLO-2D Model), the description of the model is insufficient.
- In Equation 1 and 2, a description of the variables should be added under each equation.
- The quality of figures (Figure 2, 5, 6, 8) should be improved.
- The source of figure 7 including the information of satellite should be written.
- In the end of Conclusion, the content of related future studies is required.
Finally, I hope that my comments will help you complement your study.
Author Response
Dear Reviewer,
We appreciate for your careful reading and helpful comments. Those comments are very valuable and constructive for revising and improving our paper, as well as the significance of our research. We have addressed the points noted below. You will find our general reply and point-by-point responses in the attachment.Thank you very much.
Sincerely Yours,
Ningyue Chen
Dept. of Hydrology and Water Resources, Wuhan University, China
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Dear Authors,
Thank you for taking my comments on board and addressing them.
I only have a few very minor points that need to be addressed.
- Table 3: Please add units for "Difference in time between simulated and observed peak occurrence".
- Regarding TOPMODEL please mention how this model was calibrated.
Author Response
Dear Reviewer,
We appreciate for your careful reading and helpful comments. Those comments are very valuable and constructive for revising and improving our paper, as well as the significance of our research. We have addressed the points noted below. You will find our general reply and point-by-point responses in the attachment.Thank you very much.
Sincerely Yours,
Ningyue Chen
Dept. of Hydrology and Water Resources, Wuhan University, China
Author Response File: Author Response.pdf
Reviewer 2 Report
Dear Authors,
You have done a great job in reviewing your initial version of the manuscript. My comments and observations have been addressed in a good manner.
Kind regards!
Author Response
Dear Reviewer,
We appreciate for your careful reading and helpful suggestions that have helped improve this paper substantially. Thank you very much！
Sincerely Yours,
Ningyue Chen
Dept. of Hydrology and Water Resources, Wuhan University, China
