Large-Scale Two-Dimensional Cascade Modeling of the Odra River for Flood Hazard Management

Round 1

Reviewer 1 Report

The study is very interesting and fascinating and offers an interesting trains of thought for the assessment of the exposure to flood in large basin in sites located along the Odra river. The study also offers a methodology for modelling the flood risk useful as a tool for the disaster management sector in order to increase the resilience of the sites potentially affected by these events.

The paper is well structured and written. I have only some suggestion about the bibliographic reference:

Lines 28-29. “This year has seen severe flooding in the South of Europe,….” I think it is better to specify the year instead of “this year”

Lines 41-42 Could the Author rephrase this sentence “A systematic overview of models for determining flood propagation and inundation is provided in [3,5-8]” in order to avoid to have only the numbers as citation? In general, it could be better to have a complete sentence followed by citation [3,5-8).

This comment is valid for all the similar citations in the text. For example:

Lines 50-51. “…channels (e.g. [13]).” could be “…channels (e.g. Willems et al. 2023 [13])”

Line 64. “For example, [21,22] showed that…” could be “ For example, Cook and Merwade (2009) and Falter et al. (2016) [21,22] showed that…”

Line 71. “[24] concluded that the model’s…” as above

Lines 80-81. “According to [8], all searched 2D…” as above

Line 103. “[25] proposed a flood inundation…” as above

and so on: Lines 108, 110

Lines 150-151 the sentence This area includes a 600 km long 150 section of the Odra River is reported twice. Please, delete one of these.

Line 601. Fig 8 please is the term “Maksimum” correct? Do you intend maximum?

Author Response

Dear Reviewer,

thank you very much for the appreciation of the work.

The referencing has been adapted.

Kind regards,

Author

Reviewer 2 Report

I find the article an intersting one that addresses the topic of flood risk. Importantly, it has practical applications to many aspects of human and infrastructure safety. I recommend the article for publication after taking into account the following comments.

This year has seen severe flooding in the South of Europe, and a catastrophic flood that killed thousands of people in the city of Derna in Libya. The sentence implies that the Line is in southern Europe.

In the article, I do not find a clearly stated purpose of the research. It should be found in the Introduction section, before subsection 1.1.

Line: 153-154: The research was initiated more  than 10 years ago, and the paper aims to summarize the achievements and experience  gained during that time. The purpose of the research, so formulated, qualifies the status of the article as a review.

Figure 2: What do the colors presented mean?

The article lacks a Discussion section, which easily allows the reader to analyze the results obtained against similar studies.

Please expand on the information regarding flood control development built after 1997. In addition, what is the future plan of action in this area and what impact will this have on the simulations presented.

Author Response

Comment:I find the article an intersting one that addresses the topic of flood risk. Importantly, it has practical applications to many aspects of human and infrastructure safety. I recommend the article for publication after taking into account the following comments.

Response: Thank you very much for your positive evaluation and comments.

This year has seen severe flooding in the South of Europe, and a catastrophic flood that killed thousands of people in the city of Derna in Libya. The sentence implies that the Line is in southern Europe.

Response: Corrected.

In the article, I do not find a clearly stated purpose of the research. It should be found in the Introduction section, before subsection 1.1.

The research purpose is introduced by the prior statement (l. 139-151). The scope and purpose of the research/article is rewritten. It is left before Section 2. Subsection 1,1 is thought as a part of the positioning of the work, still forming the introduction.

Taking the above into consideration, the paper presents the unique concept of 2D modelling for a large area. This area includes a 600 km long section of the Odra River, for which a series of complementary interlinked hydrodynamic models in a cascade arrangement was prepared using commercial MIKE21 software. The research was initiated more than 10 years ago in order to provide new numerical tools that help to resolve multiple scientific and practical problems related to the river’s hydrology and flood hazard management. The paper aims to describe the achievements and experience gained during that time. Several relevant case studies are presented. In addition, various aspects related to the acquisition of data and the solving of problems that occur during the development and use of 2D models are described.

Line: 153-154: The research was initiated more  than 10 years ago, and the paper aims to summarize the achievements and experience  gained during that time. The purpose of the research, so formulated, qualifies the status of the article as a review.

The article may indeed be considered as a review, but the research context and the methodological approach is important, hence the status of the article can be sustained, in my opinion.  

Figure 2: What do the colors presented mean?

Response: Thank you for this remark. A legend is added.

The article lacks a Discussion section, which easily allows the reader to analyze the results obtained against similar studies.

Response:

Actually, I considered adding a Discussion section in the manuscript. However, the article is multi-threaded, hence a concise discussion may be a bit problematic. Therefore the discussion is incorporated in particular sections of model application, also section 7 takes this role. Separate Discussion would extend the size of the article that I wanted to avoid for different reasons (including getting beyond the available budget for the publication). On the other hand, such an article structure is not unique; can be found in multiple overview and guidance papers.

Please expand on the information regarding flood control development built after 1997.

Response:

Thank you for this suggestion. Information on flood control development were cited in [44,45]. In addition a paragraph is added and a number of flood embankments (re)constraction in the text, as below. A website is referenced as a source of information in English [https://odrapcu.pl/en/project-orfpp/about-project-orfpp/]:  

L. 182-191. Information on the major investment project is added information on flood embankments is added:

In 2007 the Odra River Basin Flood Protection Project was implemented. The main objective of the Odra River Basin Flood Protection Project was to enhance flood protection for areas located in the Odra valley, from Racibórz downstream to Wrocław. This objective was achieved by the construction of the Racibórz dry polder and improvements to the flood control structures and facilities of the Wrocław Water Node designed to increase the flood carrying capacity of the Odra River channels through and around Wrocław. The Project provided flood protection for the population living in Racibórz, Kędzierzyn-Koźle, Krapkowice, Opole, Brzeg, Oława, and Wrocław as well as other towns and villages located in the Odra valley in three voivodeships (regions): Śląskie, Opolskie, and Dolnośląskie [https://odrapcu.pl/en/project-orfpp/about-project-orfpp/#].

L. 439. Information on the flood protection scale is added:

…and the construction or reconstruction of 140 km flood embankments.

In addition, what is the future plan of action in this area and what impact will this have on the simulations presented.

This refers to the planning of flood management, which is not the major subject of the article, therefore and I would not like to discuss it more extensively. Flood hazard management activities conform with the EU legislation  are presented in section 6.1. Currently, a new cycle has started with all its phases. As a rule, all new interventions are analysed in terms of its potential impact on the flood hazard. Addressing the comment, another paragraph is added in Section 7:

The elaborated 2D models were used multiple times for the assessment of the efficiency of flood protection measures, i.e. the models were updated to be consistent with the actual or design conditions. Similar ones can be used in the future, e.g. for the purpose of constructing new flood embankments between Racibórz and Kędzierzyn Koźle. These investments can easily be incorporated into the model(s), whereas flood hazard maps can be updated (if the impact of these activities on the risk of flooding will be qualified as significant). Other operations related to the current project entitled Odra-Vistula Flood Management Project can also be used in a similar way [https://odrapcu.pl/en/strona-glowna-english/]. This can be done within the ongoing third cycle of the management of flood hazards in Poland.