Understanding and Mitigating Urban Flood Risk

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper summarized some commen findings on urban flooding, but lacked in-depth opinions on flooding evidence, data requirement, modelling technique, and flood formation mechanism.

Author Response

COMMENT

This paper summarized some commen findings on urban flooding, but lacked in-depth opinions on flooding evidence, data requirement, modelling technique, and flood formation mechanism.

RESPONSE

I fully agree with the reviewer. I misinterpreted the genre of article I was requested to write. I initially understood that I needed to compose a document to provoke discussion. I have now modified the title to concentrate more explicitly on risk assessment and its mitigation, and I have created a revised version that tries to integrate the reviewer feedback and expresses my personal viewpoints on the matter.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear prof. Todini,

I have a single observation regarding manuscript lines 35-36, which could be modified to convey a more precise message.

In the text you write: "in the context of urban flooding, a hazard could be heavy rainfall events overflowing rivers or poor drainage systems".

I suggest that, in the conditions you cite, the hazardous phenomenon to be considered is the act itself of the river or drainage system overflowing due to heavy rains and not its origin. For this reason, the sentence could be reformulated as follows:

"In the context of urban flooding, the hazard could be the probability of the river or poor drainage system overflowing due to a heavy rainfall event".

This slight modification of the hazard definition adheres more to the classical concept of risk quantification via the formula R = HEV, where H is the occurrence probability of the adverse phenomenon. This definition, which moves the probability evaluation from the causes to the effects, avoids some logical inconsistencies highlighted in the multivariate case by Volpi and Fiori (2014) and Serinaldi (2015). This is also more consistent with the contemporary concepts developed in Todini and Reggiani (2024).

 

Regards

 

References

Serinaldi F. (2015) Dismissing return periods!, Stochastic Environmental Research and Risk Assessment 29, 1179-1189.

Todini E., Reggiani P. (2024) Toward a new flood assessment paradigm: from exceedance probability to the expected maximum floods and damages, Water Resources Research 60, e2023WR034477.

Volpi E., Fiori A. (2014) Hydraulic structures subject to bivariate hydrological loads: return period, design, and risk assessment, Water Resources Research 50, 885-897.

Author Response

COMMENT

I have a single observation regarding manuscript lines 35-36, which could be modified to convey a more precise message.

In the text you write: "in the context of urban flooding, a hazard could be heavy rainfall events overflowing rivers or poor drainage systems".

I suggest that, in the conditions you cite, the hazardous phenomenon to be considered is the act itself of the river or drainage system overflowing due to heavy rains and not its origin. For this reason, the sentence could be reformulated as follows:

"In the context of urban flooding, the hazard could be the probability of the river or poor drainage system overflowing due to a heavy rainfall event".

This slight modification of the hazard definition adheres more to the classical concept of risk quantification via the formula R = HEV, where H is the occurrence probability of the adverse phenomenon. This definition, which moves the probability evaluation from the causes to the effects, avoids some logical inconsistencies highlighted in the multivariate case by Volpi and Fiori (2014) and Serinaldi (2015). This is also more consistent with the contemporary concepts developed in Todini and Reggiani (2024).

RESPONSE

I appreciate the reviewer's comment, which I acknowledge, and have revised the manuscript accordingly.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript lacks substantial engagement with existing literature. Urban flooding is a complex and wide-ranging issue that affects regions across the globe. While the author provides a general overview of urban floods, including their characteristics, associated risks, and potential mitigation strategies, the discussion remains superficial and lacks a coherent, in-depth flow of knowledge.

The manuscript would benefit greatly from the inclusion of case studies or historical urban flood events to provide context and strengthen the justification of key points. Currently, no specific study sites are presented to help ground the reader’s understanding of urban flooding processes in a real-world setting. Ideally, each major theme or paragraph should be supported with relevant examples or event-based evidence to enhance clarity and credibility.

Additionally, the manuscript lacks any clear novelty or original contribution to the field. Although the importance of flood modeling is mentioned, there is no supporting literature referenced to back up these claims. For the manuscript to be considered a valuable academic contribution, it should not only include relevant references but also clearly state how the presented work advances current knowledge or practice.

Author Response

COMMENT 1

The manuscript lacks substantial engagement with existing literature. Urban flooding is a complex and wide-ranging issue that affects regions across the globe. While the author provides a general overview of urban floods, including their characteristics, associated risks, and potential mitigation strategies, the discussion remains superficial and lacks a coherent, in-depth flow of knowledge.

RESPONSE 1

I agree with the reviewer. I misinterpreted the genre of article I was requested to write. I initially understood that I needed to compose a document to provoke discussion. I have now modified the title to concentrate more explicitly on risk assessment and its mitigation, and I have created a revised version that tries to integrate the reviewer feedback and expresses my personal viewpoints on the matter.

COMMENT 2

The manuscript would benefit greatly from the inclusion of case studies or historical urban flood events to provide context and strengthen the justification of key points. Currently, no specific study sites are presented to help ground the reader’s understanding of urban flooding processes in a real-world setting. Ideally, each major theme or paragraph should be supported with relevant examples or event-based evidence to enhance clarity and credibility.

RESPONSE 2

I certainly understand, but I do not entirely concur with the necessity of providing a real example for each point in the manuscript; however, I have incorporated examples of historical cases in the revised version.

COMMENT 3

Additionally, the manuscript lacks any clear novelty or original contribution to the field. Although the importance of flood modeling is mentioned, there is no supporting literature referenced to back up these claims. For the manuscript to be considered a valuable academic contribution, it should not only include relevant references but also clearly state how the presented work advances current knowledge or practice.

RESPONSE 3

Again, I apologize, but I find it unnecessary to delineate the hydraulic models required for depicting urban floods, as this subject is addressed in other contributions within the same special issue. I favored discussing unresolved issues, specifically the return period in intervention planning and the application of predictive uncertainty in risk reduction decisions.