Understanding Flood Risk Perception: A Case Study from Canada

Round 1

Reviewer 1 Report

The study “Understanding Flood Risk Perception: A Case Study from Canada” applied a perception-based approach to analyze flood risk. The topic is interesting and well written in general. However, I would like the authors to address my following comments diligently before the manuscript can be accepted for publication.

• The abstract should include the key findings of this study. The authors only discuss the implications of this study.
• In this study, perceived flood risk has been analyzed. However, biophysical parameters are very important in quantifying flood risk. The authors need to justify the perception-based approach to understanding risk over physical approaches.
• The authors only reviewed articles that utilized public perception in analyzing risk. However, they need to include literature where flood risk is calculated based on physical modeling approaches. The following studies can improve the motivation of this article:

https://doi.org/10.1016/j.landusepol.2020.104868

https://doi.org/10.1007/s11069-008-9277-8

https://doi.org/10.1680/wame.2003.156.3.235

• The contribution of this study needs clarifying. The authors mainly argued that “In Canada, studying perception of flood risk is, however, in its early stages” [line 89]. However, globally perception-based flood risk studies are not new. Please refer to the following articles:

https://doi.org/10.5194/nhess-13-3013-2013

https://doi.org/10.1007/s11069-018-3480-z

https://doi.org/10.1111/j.1539-6924.2010.01571.x

The authors should justify their study in relation to the existing studies conducted elsewhere in the world. They should clearly highlight what new this study offers to the literature.

• Figure 2 should be reproduced by including an inset map of Canada and highlighting the studied watershed.
• Figure 3: Did the author simulate inundation? If so, how it has been validated? What are the input parameters in the GARI model apart from the river discharge?
• In terms of results, the authors mainly showed descriptive statistics of the survey responses. It would have been more interesting had they attempted to develop a statistical model explaining the factors influencing risk perceptions. I would like them to justify the choice of the analyses presented in this study.
• Uncertainty statements regarding this study should be included in the discussion or conclusion section.

Author Response

Response to reviewers’ comments

Reviewer 1

Comments and suggestions

The study “Understanding Flood Risk Perception: A Case Study from Canada” applied a perception-based approach to analyze flood risk. The topic is interesting and well written in general. However, I would like the authors to address my following comments diligently before the manuscript can be accepted for publication.

Authors’ response: the authors would like to thank the reviewer #1 for your appreciation of the value of our work. Thank you very much for providing many detailed suggestions and comments.

• The abstract should include the key findings of this study. The authors only discuss the implications of this study.

The authors thank the reviewer for this positive comment. As suggested, we have rewritten the “Abstract” section to include the major findings of this study to better understand the results and implications of our findings.

• In this study, perceived flood risk has been analyzed. However, biophysical parameters are very important in quantifying flood risk. The authors need to justify the perception-based approach to understanding risk over physical approaches.

The authors only reviewed articles that utilized public perception in analyzing risk. However, they need to include literature where flood risk is calculated based on physical modeling approaches. The following studies can improve the motivation of this article:

https://doi.org/10.5194/nhess-13-3013-2013

https://doi.org/10.1007/s11069-018-3480-z

https://doi.org/10.1111/j.1539-6924.2010.01571.x

The authors should justify their study in relation to the existing studies conducted elsewhere in the world. They should clearly highlight what new this study offers to the literature.

Thank you for this comment. As suggested by the reviewer, we have added a paragraph in the “Introduction” section to further explain the risk analysis in relation to its physical approaches. In addition, we have added the references suggested in the “introduction” section. 

• Figure 2 should be reproduced by including an inset map of Canada and highlighting the studied watershed.

The figure 2 has been changed with the proposed suggestions.

• Figure 3: Did the author simulate inundation? If so, how it has been validated? What are the input parameters in the GARI model apart from the river discharge?

The authors appreciate the reviewer for this important comment. Yes, the author did the simulation of GARI model (Oubennaceur, et al. [2019]). Flood inundation areas were computed using the GARI tool’s flood mapping module. This component is based on the CADYRI model [2]. This model can simulate the associated water level for a given discharge and subsequently determine the extent of the flooded area and the submersion heights at each point of the flooded area, using a DEM model. The module is based on a simple regression model based on the water level-discharge function (H = aQ^B) at each point of the domain [3].

The main input parameters in this model are : Lidar digital elevation model (DEM) with 1 m resolution, geometric data (boundaries and river centerline), two matrices containing the a and b regression parameters for each cell of the domain. They are estimated using the results of hydraulics simulations generated by the program (“Programme de détermination des cotes de crues”) set forth by Ministry of the Environment and Climate Change to determine the flood stage. These details are added in the “3.2 Section: Flood risk assessments tools”.

The validation of Flood Mapping module of GARI model is carried out by the aerial ortho-photo taken on April 26, 2019 in the Petite Nation basin. The validation was also compared with results of hydraulics simulations generated by Ministry of the Environment and Climate Change.

• In terms of results, the authors mainly showed descriptive statistics of the survey responses. It would have been more interesting had they attempted to develop a statistical model explaining the factors influencing risk perceptions. I would like them to justify the choice of the analyses presented in this study.

Uncertainty statements regarding this study should be included in the discussion or conclusion section.

Thank you for this important comment. This study of flood risk perception lacks some methodological limitations such as performing a statistical analysis explaining the factors influencing risk perceptions. Indeed, due to the low size of the sample (130), our sample is not representative enough to make an in-depth analysis of this survey. We did not possess enough data to have used multivariate analyses to examine the association between risk perception and socio-demographic variables. In addition, the survey as restricted to only few municipalities and the answer of this survey is not representative of the population of the Petite Nation watershed. Consequently, we can conclude that there is an important need to perform further research to explore the relationship between perceived flood risk and its main determinants with a various statistical model (as multilevel linear regression, ANOVA, mixed effects logistic model, etc.). This needs to make a very representative and large sample in the survey. This issue is acknowledged such a main limitation of the study in the “Discussion“section. Despite these limitations, the present study has provided increased insights into the public perceptions of flood risks and help decision makers to develop effective flood risk communication strategies and flood risk reduction policies.

1. Oubennaceur, K.; Chokmani, K.; Nastev, M.; Lhissou, R.; El Alem, A.J.I.j.o.d.r.r. Flood risk mapping for direct damage to residential buildings in Quebec, Canada. 2019, 33, 44-54.
2. Tanguy, M. Cartographie du risque d’inondation en milieu urbain adaptée à la gestion de crise: Analyse préliminaire. 2012.
3. Tanguy, M.; Chokmani, K.; Bernier, M.; Poulin, J.; Raymond, S.J.R.S.o.E. River flood mapping in urban areas combining Radarsat-2 data and flood return period data. 2017, 198, 442-459.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

This submission traces a paper "Understanding Flood Risk Perception: A Case Study from Canada". The paper explores people's perception of flood risk in the Petite Nation River watershed, located in southern Quebec, Canada.

The article presents an interesting work with a great aspect of significant novelty. The manuscript is well written and organized. The text is very clear and provides a unique and easy approach to the comprehensive framework for quantifying and analyzing different aspects related to flood risk, such as flood hazard experience, the physical changes occurring in the environment and climate change, the information accessibility, the flood risk governance, the adaptation measures, and finally the perception of losses. 

Although I am sure that this process has been carried out rigorously and the results will be of interest to all scientific communities, I am convinced by the applicability of the study to subsequent studies, given that it provides a reliable better understanding of the flood perceptions of flood risk and its associated determinants and does explicitly make broader contributions to the assessment field.

If we disregard the stated quality of research, I would just like to propose several suggestions to the author(s) of the article.

Firstly, in my opinion, it would be good to graphically describe the applied methodology using the process diagram. This will give a clearer and broader view of applied techniques and methods of a survey about different aspects related to flood risk. 

In addition, please justify convincingly why this manuscript (method, research, etc.) connected with Sustainability Journal content and scope.

The number of people surveyed is very small so some global conclusions can be drawn about the different aspects related to flood risk. It would be desirable to increase the number of survey participants to obtain relevant survey results.

Also, the Figures are poorly presented. Better presentation and annotation is required for publication in an international journal.

 

Author Response

Response to reviewers’ comments

 Reviewer 2

 Comments and suggestions

This submission traces a paper "Understanding Flood Risk Perception: A Case Study from Canada". The paper explores people's perception of flood risk in the Petite Nation River watershed, located in southern Quebec, Canada.

The article presents an interesting work with a great aspect of significant novelty. The manuscript is well written and organized. The text is very clear and provides a unique and easy approach to the comprehensive framework for quantifying and analyzing different aspects related to flood risk, such as flood hazard experience, the physical changes occurring in the environment and climate change, the information accessibility, the flood risk governance, the adaptation measures, and finally the perception of losses. 

Although I am sure that this process has been carried out rigorously and the results will be of interest to all scientific communities, I am convinced by the applicability of the study to subsequent studies, given that it provides a reliable better understanding of the flood perceptions of flood risk and its associated determinants and does explicitly make broader contributions to the assessment field.

If we disregard the stated quality of research, I would just like to propose several suggestions to the author(s) of the article.

The authors would like to thank the reviewer 2 for his/her positive comments on out manuscript.

• Firstly, in my opinion, it would be good to graphically describe the applied methodology using the process diagram. This will give a clearer and broader view of applied techniques and methods of a survey about different aspects related to flood risk. 

We appreciate the reviewer for this important comment. As suggested, the authors added the Figure 6 to describe flood risk perception methodology with its main determinant.

• In addition, please justify convincingly why this manuscript (method, research, etc.) connected with Sustainability Journal content and scope.

This manuscript is connected with “Sustainability Journal” content and especially “Hazards and Sustainability” section because it aims to build a good basis for the analysis of perceptions of floods risks by people living on the affected areas in the context of the effects of climate change on floods. This study also shed lights on the communications dimension of community resilience. In addition, the question of the sustainability of the flood risk perception has been illustrated through some main components such the adaptation and compensation measures (protection of wetlands, Land use…), the climate change and physical changes in the environment. The results obtained can be used as a support for the development of a prevention and sustainable strategy against flood risks in the future.

• The number of people surveyed is very small so some global conclusions can be drawn about the different aspects related to flood risk. It would be desirable to increase the number of survey participants to obtain relevant survey results.

Thank you with this careful comment. The number of people questioned is very small in this flood risk perception survey despite these efforts and publicity campaigns made to communicate and publish the survey in social networks (such as Facebook) as well as in local newspapers in the study area. The results clearly cannot be generalised to all people in Canada. In addition, the survey was limited to a few municipalities in the study area. Therefore, the response to this survey is not representative and clearly cannot be generalized to the entire study area. This confirms the need for in-depth surveys with a much larger sample size to conduct in-depth statistical analyses using a more effective flood communication approach and effective information campaigns by authorities, media, local communities, and other agencies to raise awareness of flood risk and climate change.

This main limitation is discussed and added at the end of the “Discussion” section:

• Also, the Figures are poorly presented. Better presentation and annotation is required for publication in an international journal.

Authors’ Response: Thank you very much for this careful comment. We have changed and improved the quality of all Figures in the manuscript.

 

 

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Understanding flood risk perception: a case study from Canada   by Khalid Oubennaceur et al.

 

General comments

The manuscript is quite well structured, the aims are clear, the methodology is sound, and the conclusions are supported by the results. Furthermore, the issue is topical. However, some improvements are needed.

Specific comments

Figure 2 needs to be framed with respect to the national geographic context of Canada.

Section 3.3 (Questionnaire development) should include a table where to summarize the main statistical data (age, gender, and percentage) of the respondents for each of the six municipalities. In the same section 3.3., it is advisable avoid numbering "The project description and general information" as it cause confusion once compared with the structure of section 4 (Results) which discusses six (not seven) issues. In addition, it is suitable to provide a blank sample of the questionnaire as an appendix of the manuscript. 

The Results (section 4) should also be discussed in relation to differences in age, gender and municipality of residence of the respondents.

Line 469. Which flood insurance system is in place in Canada and Quebec? Is it a voluntary or compulsory system? A short discussion is required in relation to the greater concern about insurance premiums.

For the sake of clarity, section 5 (Discussion) should set out the arguments in the same order as they are listed in the previous section (section 4).

The conclusions should highlight concrete actions that policymakers could implement based on the results achieved by the research. Policymakers could also be proposed to insert the flood risk perception questionnaire discussed in this article in the OBVRPNS flood risk assessment tools. A new application for mobile devices (APP) or a fourth module of the GARI tool could be proposed. In this way, the perception of risk by the population could be constantly monitored and analyzed, thus improving the effectiveness of communication campaigns.

Author Response

Response to reviewers’ comments

Reviewer 3

General comments

The manuscript is quite well structured, the aims are clear, the methodology is sound, and the conclusions are supported by the results. Furthermore, the issue is topical. However, some improvements are needed.

Specific comments

First, we would like to thank the reviewer #3 for your helpful comments and suggestions.

• Figure 2 needs to be framed with respect to the national geographic context of Canada.

We thank the reviewer for this careful comment. The correction has been made in the Figure 2 by adding an inset map of Canada.

• Section 3.3 (Questionnaire development) should include a table where to summarize the main statistical data (age, gender, and percentage) of the respondents for each of the six municipalities. In the same section 3.3., it is advisable avoid numbering "The project description and general information" as it causes confusion once compared with the structure of section 4 (Results) which discusses six (not seven) issues. In addition, it is suitable to provide a blank sample of the questionnaire as an appendix of the manuscript. 

Thank you for this positive feedback. We have added the Table 2 with a descriptive analysis of socio-demographic characteristics of the respondents such gender, age, education. In addition, we have removed the numbering in "Project Description and General Information" to eliminate the confusion. Finally, the survey is inserted in the “Supplementary Materials” section.

.

“Respondents were somehow evenly distributed across the study area. The detailed distribution in the municipalities of the Petite Nation watershed was as follows (Table 2): 1% in Cheneville, 8 % Duhamel, 5 % Lac Simon, 2% Lochaber, 1 % Notre dame de la Paix, 8 % Papineauville, 17 % Ripon, 58 % Saint-André-Avellin. The majority of respondents are located in the largest cities of the Petite Nation watershed (Saint-André-Avellin and Ripon), the most affected cites most during the 2017 and 2019 floods. Among the 130 respondents, 46% were males and 54% were females. The age of respondents was as follows: 2% were under 17 years of age, 73 % between 17 and 60 years of age, and 25 % were over 60 years of age, indicating that our sample covers more people between the ages of 18 and 60 years of age. The level of education is as follows: 8% of respondents have no high school diploma, 48% have a collegial diploma, 28 % have a university diploma, and 16% have secondary school diploma. which means that the participants have a level of education intermediate to superior”.

• The Results (section 4) should also be discussed in relation to differences in age, gender and municipality of residence of the respondents.

We agree with your careful comment. We did not take into consideration the socio-demographic profile in the sampling of participants, as our study targeted mainly citizens residing within five kilometers of the Petite Nation River in order to identify their concerns related to flooding of the main river channel. Consequently, our sample is not representative enough with respect to the socio-demographic profile to make an in-depth analysis of this survey. On the other hand, we already have some existing information on these participants, which we discussed later. It should also be pointed out that some information is missing to make a thorough statistical analysis, such as the participants' field of work or study, Residence ownership, Income per month, rural or urban living, etc. We have highlighted these limitations in the “Discussion “section

• Line 469. Which flood insurance system is in place in Canada and Quebec? Is it a voluntary or compulsory system? A short discussion is required in relation to the greater concern about insurance premiums.

Thank you for this important and helpful question. The issue of flood risk insurance in Canada has been the subject of much debate for several years. To answer your question, we have added a paragraph in the “Discussion” section to summarizes the main points related to insurance coverage in Canada

“Another point that was raised by respondents regarding perceptions of the floods consequences is the insurance. Flood insurance in Canada was introduced for the first time in 2016 to reduce the pressure on government programs. This new policy is intended to pro-vide a better framework for managing and financing the risks of flooding. Since flood insurance is voluntary and not regulated and companies can choose their own policy de-sign, most offer an optional endorsement limited to overland flooding, or a bundled product that includes sewer backup. This marked a significant shift in Canada’s approach to Flood Risk Management (FRM) by introducing a risk-based flood recovery mechanism. Canada’s insurance industry has been proactively engaging with the government to address gaps in coverage and affordability, but more work is necessary to ensure that flood policies and services are effective, affordable, and appropriate across all re-gions and communities across Canada”.

• For the sake of clarity, section 5 (Discussion) should set out the arguments in the same order as they are listed in the previous section (section 4).

We agree with reviewer comment. The arguments have been placed in the same order as they are listed in the previous section (section 4).

• The conclusions should highlight concrete actions that policymakers could implement based on the results achieved by the research. Policymakers could also be proposed to insert the flood risk perception questionnaire discussed in this article in the OBVRPNS flood risk assessment tools. A new application for mobile devices (APP) or a fourth module of the GARI tool could be proposed. In this way, the perception of risk by the population could be constantly monitored and analyzed, thus improving the effectiveness of communication campaigns.

Thank you for this comment. We have completed and reworked the conclusion to include all these elements. Please see the paragraph added at the end of the “Conclusion” section.

Added paragraph:

“Based on the results of this study, policy makers could implement some actions in order to increase the flood risk awareness of the population of the Petite Nation watershed. Ideally, each inhabitant should know if he lives in a flood zone or not and what is the probability of being flooded. Small municipalities rarely have the technical resources to develop such an application. But some work could be done jointly with the regional government or the watershed authority. Otherwise, some commercial applications, often with insurance companies, are also available which provide this kind of information for each household. A municipality could inform its population of this possibility.

Although a majority of respondents consider that the information for emergency planning in flood prone areas is generally available and accessible, there is still a significant percentage for whom it is not. Policymakers should work on improving these aspects. It has also been noted that people often get their information through traditional and social media during the flood event. A municipality could organize public workshops each winter to improve preparedness, by communicating and explaining the different resources available for individual risk management. These types of sessions could also cover climate change impacts and different kinds of climate risks, as well as information on the impact of floods on property value. To increase the number of people that are better prepared to face floods workshops should be held yearly and backed up by a communication strategy. Then, a survey like the one used in this study could also be done every year to monitor the evolution of the level of awareness and preparedness of the population and constantly adapt the policymaker’s strategy”.

 

 

 

 

 

 

 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

• I like to thank the authors for their attempts to address my comments. However, I still feel the background of this study must highlight the main contributions of this study. 
• In the response notes, the authors only stated that my comments have been addressed. However, it is not clear how each of my comments was considered. And which lines in the manuscript were revised based on those comments. A clear discussion in the response notes enables reviewers to evaluate a manuscript efficiently. 
• Overall, the revised version is an improvement from the original submission. This version can be accepted for publication after revising the introduction section. As I suggested previously, the following recent studies could help to improve the global readership of this study. 

https://doi.org/10.1038/s41893-021-00846-9

https://doi.org/10.1111/j.1539-6924.2010.01571.x

 

Author Response

Response to reviewers’ comments

 Reviewer 1

Comments and suggestions

I like to thank the authors for their attempts to address my comments. However, I still feel the background of this study must highlight the main contributions of this study. 

In the response notes, the authors only stated that my comments have been addressed. However, it is not clear how each of my comments was considered. And which lines in the manuscript were revised based on those comments. A clear discussion in the response notes enables reviewers to evaluate a manuscript efficiently. 

Overall, the revised version is an improvement from the original submission. This version can be accepted for publication after revising the introduction section. As I suggested previously, the following recent studies could help to improve the global readership of this study

https://doi.org/10.1038/s41893-021-00846-9

https://doi.org/10.1111/j.1539-6924.2010.01571.x

First, we would like to thank the reviewer 1 for his/her positive and constructive comments on the manuscript. Below is our response to the issues raised in the review.

Based on your recommendation, the introduction has been revised by adding new paragraphs (highlighted in yellow color). Also, as suggested by the reviewer, we added the references:

https://doi.org/10.1111/j.1539-6924.2010.01571.x (page 3 - line 112)

https://doi.org/10.1038/s41893-021-00846-9 (page3 - line 102)

Finally, we sincerely apologize for not putting the line numbers to facilitate the reading and the changes made in the previous round. You will find below the page and line numbers in the relevant parts.

Thank you again for your time!

Reviewer 1 (Round1)

Comments and suggestions

• Firstly, in my opinion, it would be good to graphically describe the applied methodology using the process diagram. This will give a clearer and broader view of applied techniques and methods of a survey about different aspects related to flood risk. 

We appreciate the reviewer for this important comment. As suggested, the authors added Figure 6 (L. 229 – P. 6) to describe flood risk perception methodology with its main determinant.

• In addition, please justify convincingly why this manuscript (method, research, etc.) connected with Sustainability Journal content and scope.

This manuscript is connected with “Sustainability Journal” content and especially “Hazards and Sustainability” section because it aims to build a good basis for the analysis of perceptions of floods risks by people living in the affected areas in the context of the effects of climate change on floods. This study also shed light on the communications dimension of community resilience. In addition, the question of the sustainability of the flood risk perception has been illustrated through some main components such the adaptation and compensation measures (protection of wetlands, Land use…), climate change, and physical changes in the environment. The results obtained can be used as support for the development of prevention and sustainable strategy against flood risks in the future.

• The number of people surveyed is very small so some global conclusions can be drawn about the different aspects related to flood risk. It would be desirable to increase the number of survey participants to obtain relevant survey results.

 

Thank you for this careful comment. The number of people questioned is very small in this flood risk perception survey despite these efforts and publicity campaigns made to communicate and publish the survey in social networks (such as Facebook) as well as in local newspapers in the study area. The results clearly cannot be generalized to all people in Canada. In addition, the survey was limited to a few municipalities in the study area. Therefore, the response to this survey is not representative and clearly cannot be generalized to the entire study area. This confirms the need for in-depth surveys with a much larger sample size to conduct in-depth statistical analyses using a more effective flood communication approach and effective information campaigns by authorities, media, local communities, and other agencies to raise awareness of flood risk and climate change.

This main limitation is discussed and added at the end of the “Discussion” section. (P 22. Line 673- Line 682)

• Also, the Figures are poorly presented. Better presentation and annotation are required for publication in an international journal.

Authors’ Response: Thank you very much for this careful comment. We have changed and improved the quality of all Figures in the manuscript.

 

 

 

 

 

 

 

 

 

 

 

Author Response File: Author Response.docx

Reviewer 3 Report

The authors made a significant revision of the manuscript, implementing all suggestions.

Based on the new key considerations made in the "Discussions" and "Conclusions" sections, I also recommend authors to hint  at the (significant) practical usefulness of Big Data for both policymakers and stakeholders.

In fact, through Big Data it is possible to assess the interest of people and internet users on the flood topic thus taking advantage of the time immediately after the occurrence of an event to implement timely and geographically targeted campaigns to increase both the perception of risk in the population and stimulate preparedness measures, such as the purchase of insurance policies to compensate losses, as ascertained by recent studies (https://doi.org/10.1111/area.12719,  https://doi.org/10.1057/s41599-020-0532-2) both in the context of floods and in the context of other natural hazards.

These aspects can be included with one paragraph or two in Discussions or Conclusions sections.

Congratulations to the authors on their research.

 

 

 

Author Response

Response to reviewers’ comments:

 Reviewer 3

 Comments and suggestions

The authors made a significant revision of the manuscript, implementing all suggestions.

Based on the new key considerations made in the "Discussions" and "Conclusions" sections, I also recommend authors to hint at the (significant) practical usefulness of Big Data for both policymakers and stakeholders.

In fact, through Big Data it is possible to assess the interest of people and internet users on the flood topic thus taking advantage of the time immediately after the occurrence of an event to implement timely and geographically targeted campaigns to increase both the perception of risk in the population and stimulate preparedness measures, such as the purchase of insurance policies to compensate losses, as ascertained by recent studies (https://doi.org/10.1111/area.12719,  https://doi.org/10.1057/s41599-020-0532-2) both in the context of floods and in the context of other natural hazards.

These aspects can be included with one paragraph or two in Discussions or Conclusions sections.

We would like to thank the reviewer 3 for his/her positive and very thorough comments on the manuscript. As suggested by the reviewer, we have added a paragraph about Big Data technologies in the Discussion section (Page 22- Line 682).

Thank you again for your time and positive comments!

 

 

Author Response File: Author Response.docx