Review Reports

Round 1

Reviewer 1 Report

This paper is about the possible impact that climate change could have in the future of New Orleans, which in the past has already experimented several floods, and on the sustainability of the Mississippi River and Tributaries Project that was implemented after the 1927 flood on the Mississippi River.

The paper has a very detailed introduction about the past events that hit Lousiana and New Orleans and the actions taken during the last decades to face the problem. Even I found the paper extremely interesting, I think it would be interesting to accompany this study with some numerical experiments to simulate how future climate projections could affect the city of New Orleans. That said, I suggest the publication in the present form.

I attach a pdf file with very few tracked changes.

Comments for author File: Comments.pdf

Author Response

Please see attached for responses to all reviewers comments.

Author Response File: Author Response.docx

Reviewer 2 Report

The article is well written, contains beuatiful graphs, and its contents are of high interest for readers of ''water''. It presents an extensive description of the many flood related  problems that the lower Mississippi basin and especially New Orleans has to deal with. In itself this is already valuable for publication. Additionally, some beginning of an analysis of the causes has been made and a start of "sustainable" solutions are mentioned.

The article reads as if it is written from the perspective of the regional situation, without placing it in higher level considerations of new world delta management. Much high level local literature has been used, but the global level misses.

Because of the large text about the problems, there seems not to be enough space left for a theoretical frame and a clear, well argumented, path of solutions. Also the aim of the article, its research question and its research methods are not well addressed. The structure is not clear and slightly unbalanced with the large enumeration of ''facts of deterioration'' and the short paragraphs with solutions. 

To improve the article I have the following suggestions:

• abstract does not read as a logical narrative about the contents of the article. Please make more clear what is the idea of the article. 
• make a clear introduction to the text (not the first part of the contents), with research question, aim, structure of the article and research methods;
• create structure in the second and third  paragraph and summarize where possible.
• Add a theoretical frame in which the ideas of the authors about sustainable flood management are explained. Now everything that can improve the currect situation seems to be a sustainable solution. What about Integrated water (resources) management, Adaptive water managemement, ecosystem based engineering, Interactive water management/flood management etc. the last sentences seem to conclude this but do not put it on the theoretical level. Maybe European literature could help here... 
• It seems obvious that only extra sedimentation that can compensate sea level rise and land subsidence is a really sustainable option. But alternatives are presented everywhere. Explain why the authors select this option. Not just stating it like in lines 408-409 and 22. An adequate theoretical argumentation could help here.
• Some paragraphs are quite short where others are really long. It would be possible to create more balance.
• see table 1, number 32 -end.

The nature of the article deserves it to be further improved! 

Author Response

Reviewer 2

 

Comment. The article reads as if it is written from the perspective of the regional situation, without placing it in higher level considerations of new world delta management. Much high level local literature has been used, but the global level misses.

 

Response: We have included a discussion of global issues in the introduction and put the lessons of the Mississippi into a global context in the conclusions.

 

Comment. Because of the large text about the problems, there seems not to be enough space left for a theoretical frame and a clear, well argumented, path of solutions. Also the aim of the article, its research question and its research methods are not well addressed. The structure is not clear and slightly unbalanced with the large enumeration of ''facts of deterioration'' and the short paragraphs with solutions.

 

Response.  We have added to the discussion of solutions.

 

Comment. Abstract does not read as a logical narrative about the contents of the article. Please make more clear what is the idea of the article.

 

Response. We have revised the abstract to address this comment. 

 

Comment. Create structure in the second and third  paragraph and summarize where possible.

Response. It is not clear what the reviewer means here.  These two paragraphs summarize the science on climate change that are affecting the delta (increasing flood levels in the Miss river, sea-level rise, and extreme precipitation events.  As noted in the response to the next comments, we put our findings into a broader context in the concluding section.

 

Comment. Add a theoretical frame in which the ideas of the authors about sustainable flood management are explained. Now everything that can improve the currect situation seems to be a sustainable solution. What about Integrated water (resources) management, Adaptive water managemement, ecosystem based engineering, Interactive water management/flood management etc. the last sentences seem to conclude this but do not put it on the theoretical level. Maybe European literature could help here... 

Response. We add a theoretical framework for deltaic functioning (that of the concept of pulsing events) and the idea that for the Mississippi delta moving beyond adaptability due to shifting baselines in the concluding section.  These concepts include the issues raised by the reviewer.  In this way it addresses the issues raised in the paper.

 

Comment. seems obvious that only extra sedimentation that can compensate sea level rise and land subsidence is a really sustainable option. But alternatives are presented everywhere. Explain why the authors select this option. Not just stating it like in lines 408-409 and 22. An adequate theoretical argumentation could help here.

Response. Our argument is that raising people and sensitive infrastructure above sea level is important for a sustainable New Orleans.  Doing this would increase protection against hurricanes.  We also suggest that some areas of the city should become water storage areas.  We clarify these issues in the text

 

Comment. Some paragraphs are quite short where others are really long. It would be possible to create more balance.

Response. We have revised the text to do this.

 

Comment. See table 1, number 32 -end.

Response. This has been revised.

 

Comment. create structure in the second and third  paragraph and summarize where possible.

Response. See comments above. We have developed a conceptual framework that summarizes the information in this paragraph in the concluding section.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

The paper about The “Problem” of New Orleans and Diminishing Sustainability of Mississippi River Management – Future Options brings important information on the evolution and challenges that an area affected by extreme hydrological phenomena tends to improve.

Entire paper doesn't fulfill the requirements of publication in this journal and need some important improvement

1. Figure 1 has no scale of representation and also need to show the geographical North
2. Figure 2 is not very clear
3. The authors of this paper must establish the units of measurements  m³/s of cfs for discharges in text and also in figure 3, 4, 5 and 6
4. the equations in figure 4 is not necessary
5. in figure 9 appear in the left side the year 2011?
6. The paper has not a clear part of methods and data bases and also does not have a clear part of results and conclusion. The authors must reorder the information for reach the requirements of a scientific paper

Author Response

Comment. The paper about The “Problem” of New Orleans and Diminishing Sustainability of Mississippi River Management – Future Options brings important information on the evolution and challenges that an area affected by extreme hydrological phenomena tends to improve.

Response. We thank the reviewer for this comment.  Responses to specific comments are below.

Comment. Entire paper doesn't fulfill the requirements of publication in this journal and need some important improvement.  Figure 1 has no scale of representation and also need to show the geographical North

Response. This has been added to the figure.

 

Comment  Figure 2 is not very clear

Response. We now use a different figure to show this information that is much clearer.

 

Comment The authors of this paper must establish the units of measurements m³/s of cfs for discharges in text and also in figure 3, 4, 5 and 6

Response. We realize that metric units should be used in scientific publications.  But practically all publications by the Corps of Engineers on the Mississippi River management system give flow rates in cubic feet per second.  Because of this, we present both english and metric units where appropriate so that original Corps of Engineers units are used.

 

Comment The equations in figure 4 is not necessary

Response. We disagree.  The equations are for the regression analysis for each curve.  We now describe this in the paper.

 

Comment In figure 9 appear in the left side the year 2011?

Response. The projected increases in peak river discharge from the Tao et al. paper are relative to the peak discharge in 2011.  This is now made clear in both figure 9 and the text.

 

Comment The paper has not a clear part of methods and data bases and also does not have a clear part of results and conclusion. The authors must reorder the information for reach the requirements of a scientific paper

Response.  This is primarily a review paper but where appropriate, we describe methods.  For example, we describe what data we used to create the graphs of river stage and discharge and the statistical analysis we did.  But since this is a review paper, we do not have a formal methods section.  We have revised the conclusions.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The authors fulfill all the requirements about the issues of this paper and can be published in this form.