Urban Flood Modeling for Sustainability Management: Role of Design Rainfall and Land Use

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

 

your paper, related to urban flooding modeling intended for sustainability management, represents a comprehensive contribution to the assessment of hydrological scenarios at a local scale. The paper provides certain gaps, and therefore I recommend paying attention to the following points:

 

Line 43-45: You state “numerous studies”, but you cite only two of them. I recommend the following options: (1) adding a few more references from different periods, (2) reformulating the statement or (3) emphasizing that enclosed references are review papers where thorough elaboration of the problem was exposed (of course, if this last of my propositions is correct). In addition, the influence of the drainage system is quite important. You could add one to two sentences explaining in more detail how it contributes to further vulnerability.

Line 112: Figure 1. Could you also show on the map the hydrological network forming the Dwinka catchment?

Line 103: Possible typing mistake – an extra “A”.

Line 107: Typing mistake – an extra dot at the end of the sentences.

Line 109: Please be more specific – sandy soils do not support runoff, but the opposite. To resolve this mention, e.g. % of clay soils and similar non-permeable soils.

Line 258-63: Related to Figure 2. Please explain the variables mentioned in the legend, and the meaning of the “Pmax” and incorporate this into the text.

Line 263: What period was covered by Jorasinska and Bodziony?

Line 274: Please use the same manner for “P_max” not “Pmax”.

Line 322: Please explain the meaning of “S.L.”.

Line 333: It seems that “T” is missing at the beginning of the sentence.

Line 363: Legends within the figures are too small. Please find a way to resolve this.

Line 369: What does CN stand for? And how it was calculated? Please explain this in the Material and Methods chapter.

Line 373: You mentioned table 8, but you omitted to present tables 5 and 6. Maybe you have meant table 4?

Line 375: Is CN for UA really “significantly” or just “slightly” higher?

Line 417: Table 5 is missing, as well as table 6.

Line 521-23: Include some references proving benefits of green infrastructure to mitigating urban flooding, e.g. rain gardens.

Author Response

1. Reviewer comment:

Dear authors, your paper, related to urban flooding modeling intended for sustainability management, represents a comprehensive contribution to the assessment of hydrological scenarios at a local scale. The paper provides certain gaps, and therefore I recommend paying attention to the following points.

1. Authors answer: 

We would like to express our sincere gratitude to the Reviewer for their attention. We are very thankful for the time spent reading our article. We deeply believe that the weaknesses pointed out by the Reviewer have allowed for significant improvement and enhancement of its quality. All the comments provided by the Reviewer have been taken into account in the revised version of the manuscript. The changes have been marked using the 'track changes' option.

2. Reviewer comment:

Line 43-45: You state “numerous studies”, but you cite only two of them. I recommend the following options: (1) adding a few more references from different periods, (2) reformulating the statement or (3) emphasizing that enclosed references are review papers where thorough elaboration of the problem was exposed (of course, if this last of my propositions is correct). In addition, the influence of the drainage system is quite important. You could add one to two sentences explaining in more detail how it contributes to further vulnerability.

2. Authors answer:

We thank Reviewer for the comment. We have expanded the above statement as: Numerous studies indicate that stormwater drainage systems contribute to increased runoff and decreased groundwater levels, ultimately raising the vulnerability of urban watersheds to hydrometeorological extremes like droughts and floods [1,2]. For instance, Zope et al. [2015] stated that urbanization and the expansion of impermeable surfaces result in higher volumes of stormwater runoff, exacerbating flood risks in urban areas. Yang et al. [2011] examined the role of urban spatial development on hydrologic response at both catchment and river basins. They demonstrated that flood peaks arrive earlier with urbanization. Early flood peaks in urban areas pose significant threats. They can lead to loss of life, infrastructure damage, financial losses, and environmental contamination. Intense floods can also disrupt the economy through supply interruptions and job losses. Therefore, it is necessary to develop flood risk management strategies and invest in resilient urban infrastructure. Additionally, research conducted by Minning et al. [2018] indicated strong correlation between groundwater recharge rates and the extent of the urban area. They demonstrated that the transformation of natural landscapes into impervious areas leads to an increase in groundwater recharge rates due to the reduction of evapotranspiration that more than compensates for the increase in runoff.  Furthermore, in the study of O'Driscoll et al. [2010] showed relationships between urbanization and the expansion of watershed impervious area and watershed hydrology, groundwater recharge, stream geomorphology, climate, biogeochemistry, and stream ecology These findings underscore the critical need for sustainable stormwater management practices to mitigate the adverse effects of urbanization on hydrological systems. We kindly ask to see revised manuscript, pg. 2.

3. Reviewer comment:

Line 112: Figure 1. Could you also show on the map the hydrological network forming the Drwinka catchment?

3. Authors answer:

We thank Reviewer for the comment. The figure 1 has been corrected. We kindly ask to see revised manuscript.

4. Reviewer comment:

Line 103: Possible typing mistake – an extra “A”.

4. Authors answer:

We thank Reviewer for the comment. An extra ‘A’ has been removed. We kindly ask to see revised manuscript, pg. 3.

5. Reviewer comment:

Line 107: Typing mistake – an extra dot at the end of the sentences.

5. Authors answer:

We thank Reviewer for the comment. The extra dot has been removed. We kindly ask to see revised manuscript, pg. 3.

6. Reviewer comment:

Line 109: Please be more specific – sandy soils do not support runoff, but the opposite. To resolve this mention, e.g. % of clay soils and similar non-permeable soils.

6. Authors answer:

We thank Reviewer for the comment. We corrected and provided more specific information about soils in the catchment: ‘In the catchment, soils belonging to the hydrological soil group C predominate. They are characterized by below-average permeability, with infiltration coefficients ranging from 3.8 to 7.6 mm·h^-1. These are primarily stratified soils with poorly permeable layers, clayey silts, shallow sandy clays, soils with low organic matter content, and soils with high proportions of clay particles’. We kindly ask to see revised manuscript, pg. 3. 

7. Reviewer comment:

Line 258-63: Related to Figure 2. Please explain the variables mentioned in the legend, and the meaning of the “Pmax” and incorporate this into the text.

7. Authors answer:

We thank Reviewer for the comment. We explained the variables on the figure 2. The P_max are annual daily maximum precipitation, C_v is the coefficient of variation, Z MMK is the statistic of modified Mann-Kendall test. We kindly ask to see revised manuscript, pg. 7.

8. Reviewer comment:

Line 263: What period was covered by Jorasinska and Bodziony?

8. Authors answer:

We thank Reviewer for the comment. The period was 1951-2018. The information has been added to manuscript. We kindly ask to see revised version, pg. 7.

9. Reviewer comment:

Line 274: Please use the same manner for “P_max” not “Pmax”.

9. Authors answer:

We thank reviewer for the comment. The ‘Pmax’ has been replaced with ‘P_max’ throughout entire manuscript. We kindly ask to see revised version.

10. Reviewer comment:

Line 322: Please explain the meaning of “S.L.”.

10. Authors answer:

We thank Reviewer for the comment. The ‘S.L.’ means sealing layer. We added this information for the revised manuscript, pg. 9.

11. Reviewer comment:

Line 333: It seems that “T” is missing at the beginning of the sentence.

11. Authors answer:

We thank Reviewer for the comment. The ‘T’ was added. We kindly ask to see revised manuscript, pg. 9.

12. Reviewer comment:

Line 363: Legends within the figures are too small. Please find a way to resolve this.

12. Authors answer:

We thank Reviewer for the comment. The legend was corrected. We kindly ask to see revised manuscript, figure 4.

13. Reviewer comment:

Line 369: What does CN stand for? And how it was calculated? Please explain this in the Material and Methods chapter.

13. Authors answer:

We thank Reviewer for the comment. The CN parameter (Curve Number) is a key component of the SCS-CN method, which describes the retention capabilities of watersheds. This parameter depends on several factors such as initial soil moisture, soil type, and land use in the watershed. CN parameter values range from 0 to 100, where higher values indicate limited retention capabilities of the watershed and favorable conditions for surface runoff formation. The unit values of the CN parameter were determined based on Maidment's work [1993]. Since the analyzed watershed exhibits diverse land use, the CN parameter value for this watershed was determined as a weighted average, as described in Tailor and Shrimali's work [2016].

 

CN_w =  

where:

CN_w – weighted curve number (-);

CN_i – curve number for particular land use (-),

A_i – area with curve number CN_i (km²),

A – catchment area (km²).

We kindly ask to see revised manuscript, pg. 6.

14. Reviewer comment:

Line 373: You mentioned table 8, but you omitted to present tables 5 and 6. Maybe you have meant table 4?

14. Authors answer:

We thank Reviewer for the comment. It should be ‘Table 4’, it was corrected. We kindly ask to see revised manuscript, pg. 12.

15. Reviewer comment:

Line 375: Is CN for UA really “significantly” or just “slightly” higher?

15. Authors answer:

We thank Reviewer for the comment. We believe that a difference of more than 5 between the CN values for CLC and UA is significant. It results in substantial differences in peak flows and the volumes of design hydrographs (please refer to fig. 7 and table 6).

16. Reviewer comment:

Line 417: Table 5 is missing, as well as table 6.

16. Authors answer:

We thank Reviewer for the comment. The numbers of tables were corrected throughout manuscript. We kindly ask to see revised version.

17. Reviewer comment:

Line 521-23: Include some references proving benefits of green infrastructure to mitigating urban flooding, e.g. rain gardens.

17. Authors answer:

We thank Reviewer for the comment. We added references such us:

Czyża, S.; Kowalczyk, A.M. GIS and geodata contribution to the cartographic modelling of blue-green infrastructure in urbanised areas. J. Water Land Develop. 2023, 59, 183-194.

Zaczek-Peplinska, J.; Saloni, L. Modernising the control network for determining displacements in hydraulic structures using automatic measurement techniques. . J. Water Land Develop 2023, 59, 66-75.

Gooré Bi, E.; Gachon, P.; Vrac, M.; Monette, F. Which downscaled rainfall data for climate change impact studies in urban areas? Review of current approaches and trends. Theor. Appl. Climatol. 2017, 127, 685-699.

Peixoto, J.P.J.; Costa, D.G.; Portugal, P.; Vasques, F. Flood-Resilient Smart Cities: A Data-Driven Risk Assessment Approach Based on Geographical Risks and Emergency Response Infrastructure. Smart Cities 2024, 7(1), 662-679.

We kindly ask to see revised manuscript.

Reviewer 2 Report

Comments and Suggestions for Authors

The present study evaluate how different methods of determining design rainfall levels and land usage affect flood hydrographs in an urban watershed. The paper collects a lot of relevant data, and the conclusions are of certain significance. But before you consider receiving it, you need to add the following:

1) Introduction section. Please identify existing methods of urban flood modeling for sustainability managementand key factors that affect their applicability.

2) What was the reason for choosing the study area (Drwinka River watershed)? In what ways is it representative? What are the differences or connections with existing reports?

3）In the final conclusion, can you add a comparison with existing reports to reflect the rigor of the paper?

Comments on the Quality of English Language

Moderate editing of English language required

Author Response

1. Reviewer comment:

The present study evaluate how different methods of determining design rainfall levels and land usage affect flood hydrographs in an urban watershed. The paper collects a lot of relevant data, and the conclusions are of certain significance.

1. Authors answer: 

We would like to express our sincere gratitude to the Reviewer for their attention. We are very thankful for the time spent reading our article. We deeply believe that the weaknesses pointed out by the Reviewer have allowed for significant improvement and enhancement of its quality. All the comments provided by the Reviewer have been taken into account in the revised version of the manuscript. The changes have been marked using the 'track changes' option.

2. Reviewer comment:

Introduction section. Please identify existing methods of urban flood modeling for sustainability management and key factors that affect their applicability.

2. Authors answer.

We would like to thank for the comment. We added the following information to Introduction, regarding identify existing methods of urban flood modeling for sustainability management: In hydrological practice, various techniques supporting hydrological modeling are used, in light of sustainable development of urban areas. The fusion of deep learning techniques with gradient boosting in rainfall-runoff simulation presents a promising strategy (Abdulaleva, 2023). Utilizing data-driven techniques such as airborne laser scanning (ALS), Digital Surface Model (DSM), and Digital Terrain Model (DTM) in urban areas (Piech et al., 2023), along with defined mathematical equations for risk assessment, significantly contributes to ensuring city sustainability. Numerical modeling, including two-dimensional (2-D) depth-averaged shallow-water models, is essential for accurately predicting flash flood propagation in urban areas following excessive rainfall events (El Kadi Abderrezzak et al., 2009). Addressing backwater effects and sudden flow regime changes through detailed river models further emphasizes the importance of employing 2-D models (Costabile & Macchione, 2015). Integrating hydrological and flood models to estimate surface and peak flow rates from precipitation storm events, especially in areas with high annual precipitation levels, is indispensable. For instance, modeling water pollution emergencies in urban rivers using methods like the autoregressive integrated moving average (ARIMA) and the Coupled River Basin-Urban Hydrological Model (DRIVE-Urban) underscores the importance of integrated hydrological and hydraulic modeling (Liu et al., 2024; Chen et al., 2022). Models such as the Watershed Modeling System and TuFlow, which combine one-dimensional river flow with two-dimensional surface flow models, are instrumental in effectively delineating flood risks (Şen & Kahya, 2017). Furthermore, the deployment of hydrologic software such as Hydrologic Engineering Center–Hydrological Model System (HEC-HMS) and hydraulic software like Hydrologic Engineering Center-River Analysis System (HEC-RAS) is vital for effectively managing man-made drainage systems prone to damage during intense rainfall (Feng et al., 2021).

We kindly ask to see revised manuscript, pg. 3.

 

 

 

 

 

3. Reviewer comment:

What was the reason for choosing the study area (Drwinka River watershed)? In what ways is it representative? What are the differences or connections with existing reports?

3. Authors answer:

We thank Reviewer for the comment: The choice of the Driwnka catchment is justified for significant reasons. Firstly, the Driwnka catchment is characterized by high human pressure, mainly due to intense urbanization of the area. This means that this area is particularly vulnerable to changes in the circulation of surface and groundwater, increasing the risk of urban floods. Strong sealing of the catchment leads to increased surface runoff and reduced infiltration of water into the ground. Therefore, a sharp increase in flows is observed there after heavy rainfall events. Additionally, in recent years, Driwnka has experienced many urban floods, making it an area of ​​particular importance for the analysis and understanding of mechanisms influencing this type of extreme events. We added this information to the revised manuscript, section ‘Study area’.

4. Reviewer comment:

In the final conclusion, can you add a comparison with existing reports to reflect the rigor of the paper?

4. Authors answer:

We thank Reviewer for the comment. For the discussion we added the following paragraph:

In summary, the analyses conducted unequivocally indicate that the selection of the design rainfall estimation method is a significant factor influencing the reliability of projected hydrographs, which are key outcomes of hydrological modeling. Research conducted by Ghazavi et al. (2016) demonstrated that differences in the results of hydrological models, resulting from the use of different design rainfall methods, can be significant, especially in the case of extreme event analyses, particularly peak flows. It should be emphasized that such differences can be crucial for urban infrastructure design and delineation of flood zones. Studies by Wałęga et al. (2024) unequivocally showed that for urban catchments, the extent of flooding can vary significantly depending on the adopted methodology for calculating design rainfall. The issue of design rainfall also encompasses considerations regarding duration times. Due to data availability, such rainfall is often estimated based on daily information, leading to inflated characteristics of projected hydrographs. For urban infrastructure, information on short-duration heavy rainfall is necessary. Such information can be generated using various models, such as STORAGE. Research conducted by Petroselli et al. (2023) showed that such a model can be successfully applied to simulate short-duration design rainfall, which serves as input signals for modeling projected hydrographs in urban catchments. Furthermore, research by Löwe (2018) underscores the need to consider uncertainties associated with future rainfall projections for projected hydrographs, especially in the context of identifying potential flood hazards and damages. An important aspect of hydrological analysis is also the accurate delineation of land use bases. Differences in land use classes can significantly affect surface runoff and infiltration characteristics, which in turn are crucial for generating reliable projected hydrographs. Research by Banjara et al. (2024) demonstrated that future projections of land use changes show a continuous increase in sealing, which enhances surface runoff. However, these projections vary depending on the databases used. Despite numerous limitations, CLC databases are commonly used for land use identification in various fields, including hydrological modeling (Bielecka and Jenerowicz, 2019). However, many studies have shown that the results of CLC applications regarding land cover should be interpreted with caution and awareness of methodological limitations. Jansen and DiGregorio (2002) point out the inconsistency in land cover or land use delimitation criteria. Additionally, it has been shown that land cover change maps are susceptible to errors at the local scale (Diaz-Pacheco and Gutiérrez, 2014) or unsuitable for detailed landscape analysis (Sabatino et al., 2013). In conclusion, the selection of an appropriate design rainfall method and the precise definition of land use bases are crucial aspects of hydrological modeling, significantly influencing the accuracy and reliability of generated projected hydrographs. Therefore, it is necessary to consider not only differences between rainfall estimation methods but also changes in land use to ensure accurate forecasts of hydrological events.

We kindly ask to see revised manuscript, pg. 18-19.

Reviewer 3 Report

Comments and Suggestions for Authors

The article “Urban flood modeling for sustainability management: role of design rainfall and land use” needs a major revision. For example, in the introduction the paragraphs are extremely long with many topics addressed, including aspects of climate change, flood prevention, floods as a natural process, hydrographs etc.

It mentions a higher intensity of rainfall associated with dangerous and costly floods, leaving aside the role of urbanization (line 34-35), although it later mentions its importance. I believe it is pertinent to focus the introduction on the factors associated with urban flooding and sustainability management.

In essence, the introduction does not analyze the problem to be addressed in a consistent and orderly manner; rather, the techniques used are described in a general way. This is manifested in a low consistency between the title of the article, conceptual framework/state of the art and objectives.

Regarding the methodology, it is well written from a technical point of view, but there are no new elements. Please review the following:

- Line 128: What was the purpose of using the Mann-Kendall test in the research? How did it contribute to the research?

- What is the resolution of the entries associated with the 2006 and 2008 land uses? Why did you not consider a classification using satellite images?

Lines 246-252 should go at the beginning of the methodology.

Land use results are descriptive and extensive. The change analysis is performed according to CLC and UA. There is no calibration of the hydrological models, it looks more like a sensitivity analysis.

A novel point of the article was based on the sustainability management concept indicated in the title; however, it is not addressed in the introduction, methodology, results or conclusions. In conclusion, it is a correct technical study that requires some improvements, however, from the scientific approach it lacks a clear research question or hypothesis.

Specific comments

Line 32: Episodes of constant, but less intense rainfall can cause flooding in hydrologically large watersheds. Please review.  

Figure 1 does not account for the characteristics of the watershed, it is disjointed with the proposed scales of analysis. Perhaps a map of the watershed with land use coverages or a digital elevation model. Insert coordinate system, place names.

Author Response

1. Reviewer comment:

The article “Urban flood modeling for sustainability management: role of design rainfall and land use” needs a major revision. For example, in the introduction the paragraphs are extremely long with many topics addressed, including aspects of climate change, flood prevention, floods as a natural process, hydrographs etc.

1. Authors answer:

We thank Reviewer for the comment. The comment has been taken into account. The introduction to the paper has been modified. Sections that were not relevant to the research purpose have been removed. A paragraph concerning flood issues and sustainable development has been added. The focus has been narrowed down to only the most important aspects related to the research objective, i.e., catchment sealing and the main issues with determining the shape of design hydrographs. We kindly ask to see the revised manuscript, the Introduction part.

2. Reviewer comment:

It mentions a higher intensity of rainfall associated with dangerous and costly floods, leaving aside the role of urbanization (line 34-35), although it later mentions its importance. I believe it is pertinent to focus the introduction on the factors associated with urban flooding and sustainability management.

2. Authors answer:

We thank Reviewer for the comment. We fully do agree. To the introduction, a paragraph focusing on factors related to urban floods and sustainable development has been added. We kindly ask to see the revised manuscript, the introduction section.

3. Reviewer comment:

In essence, the introduction does not analyze the problem to be addressed in a consistent and orderly manner; rather, the techniques used are described in a general way. This is manifested in a low consistency between the title of the article, conceptual framework/state of the art and objectives.

3. Authors answer:

We thank Reviewer for the comment. The introduction to the paper has been modified, focusing on the key aspects of modeling urban flood hydrology. We described two main issues: the selection of methods for calculating design rainfall and the land use databases of the watershed. This is crucial because different methods and databases may provide different information, affecting the quality of calculations. In our research, we addressed how the selection of methods for calculating design rainfall and the quality of information from different land use databases can influence the shape of design hydrographs. We believe that we have addressed very important aspects because these hydrographs are the basis for flood protection in urban areas.

4. Reviewer comment:

Regarding the methodology, it is well written from a technical point of view, but there are no new elements.

4. Authors answer:

We thank the Reviewer for pointing out the correct description of the presented calculation methodology. We fully agree that well-known tools have been described. This stems from the purpose of our analysis. Primarily, the presented tools are widely used in the broadly understood field of hydrological safety in urban areas. Unfortunately, they are often used uncritically. In our analyses, we have drawn attention to the main problems of their application. We believe that research on the impact of different methods for determining design rainfall and the use of different land use databases is significant for hydrological modeling for several reasons. Firstly, the method for determining design rainfall and the accuracy of land use data have a significant impact on flood forecasting accuracy. Choosing an inappropriate method or incorrect data can lead to underestimation or overestimation of flood risk, which has significant consequences for public safety and infrastructure. Additionally, these studies can help identify best practices and technical solutions that support the sustainable development of cities and regions, while simultaneously addressing the need for flood protection and environmental conservation. Moreover, identifying effective tools for determining design rainfall and accurate land use enables better design and management of water infrastructure, such as sewer systems, rainwater retention, and detention basins. This can increase the efficiency and resilience of these systems to extreme hydrological events. We firmly believe that our analyses and results have broad practical applicability.

5. Reviewer comment:

Line 128: What was the purpose of using the Mann-Kendall test in the research? How did it contribute to the research?

5. Authors answer:

We thank Reviewer for the comment. Verification of rainfall trend plays a significant role in hydrograph modeling. The trend in rainfall data can influence the hydrological characteristics of watersheds. If the trend is not accounted for, modeling results may be biased. Additionally, rainfall trend can affect flood risk. Increasing rainfall intensity can lead to higher frequency and intensity of floods. This is confirmed by research findings conducted by Wasko and Nathan (2019), who demonstrated such a relationship, especially in the case of flash floods characteristic of urbanized areas. Verification of rainfall trend allows for a better understanding of changes in flood risk. Moreover, hydrological forecasts are used in the design of water infrastructure. The trend in rainfall significantly impacts the required capacities and performance of these structures. Verification of rainfall trend enables proper scaling of water infrastructure, thereby minimizing flood risk. We have add this part of discussion to the revised manuscript, we kindly ask to see revised version, pg. 8.

6. Reviewer comment:

What is the resolution of the entries associated with the 2006 and 2008 land uses? Why did you not consider a classification using satellite images?

6. Authors answer:

We thank Reviewer for the comment. The resolution for the Corine Land Cover is 100 m. The resolution for Urban Atlas is about 50 m. The aim of the presented research was to conduct a comparative analysis of two land use databases, namely CLC and UA. The CLC database is one of the most commonly used for determining land use structure, in many practical aspects, including hydrological modeling. However, it has certain limitations. Therefore, we focused on presenting the Urban Atlas, which is also straightforward to interpret, while its level of detail is significantly more reliable than that of CLC. We did not analyze satellite techniques because we want to address our results primarily to practical implications. The use of satellite data often requires advanced knowledge and skills in satellite image processing and terrain classification, which can be a significant obstacle for practitioners. Therefore, we propose Urban Atlas as an alternative to CLC to simplify the analysis process.  

7. Reviewer comment:

Lines 246-252 should go at the beginning of the methodology.

7. Authors answer:

We thank Reviewer for the comment. The sentence from lines 246-252 has been moved at the beginning of methodology. We kindly ask to see revised manuscript, pg. 2.

8. Reviewer comment:

Land use results are descriptive and extensive. The change analysis is performed according to CLC and UA. There is no calibration of the hydrological models, it looks more like a sensitivity analysis.

8. Authors answer:

We thank Reviewer for the comment. We fully do agree that results of land use changes are descriptive. In the analyses presented, we conducted a comparison of differences and details between two land use databases: Corine Land Cover and Urban Atlas. The descriptive nature of the analysis stemmed from the complexity of these databases, which contain numerous categories and subcategories. Therefore, a descriptive comparison allowed for a more detailed analysis of such data. Additionally, the descriptive nature enabled a thorough examination of changes in land use within the watershed over the years 2006-2018. Such changes play a crucial role as they significantly define the theoretical hydrographs. Given that the presented analyses have high potential for implications by practitioners, we strongly believe that a descriptive comparison of this aspect of our research is more accessible to potential stakeholders. We completely agree that our work did not involve model calibration but only sensitivity analysis. It encompassed aspects related to both the magnitude of design rainfall and the CN parameter values determined in reference to land use from CLC and UA, which was the main aim of the study. Model calibration is only possible in gauged watersheds, through adjusting model parameters to obtain results as close as possible to real observations. The Driwnka watershed is ungauged, hence the lack of hydrological observations. Therefore, only model sensitivity analysis was possible.

9. Reviewer comment:

A novel point of the article was based on the sustainability management concept indicated in the title; however, it is not addressed in the introduction, methodology, results or conclusions. In conclusion, it is a correct technical study that requires some improvements, however, from the scientific approach it lacks a clear research question or hypothesis.

9. Authors answer:

We thank Reviewer for the comment. The main novelty in the conducted research is not the concept of sustainable management in light of flood occurrences in urban watersheds, but rather the analysis of the impact of choosing the method for determining design rainfall and land use of the watershed on the course of modeled design hydrographs. Such analyses are crucial for sustainable development. In the case of flood protection, sustainable development primarily concerns flood-prone areas. If design rainfall is too high and watershed sealing has been incorrectly determined, these areas will be too extensive, exceeding actual needs. This may lead to significant constraints on the development of such areas. On the other hand, excessively low design rainfall may result in narrowed zones, potentially posing significant risks to the inhabitants. We believe that in our research, we have demonstrated the limitations and differences that different methods for determining design rainfall and watershed land use structure can bring. Furthermore, we have recommended specific approaches. We firmly believe that our analyses constitute an important contribution to the scientific literature on sustainable development management, particularly in the context of flood protection, as we test hypotheses regarding the impact of choosing the method for calculating design rainfall and land use database on the course of design hydrographs. Although the concept of sustainable development management is not directly incorporated into the introduction, methodology, results, and conclusions, our analyses definitely pertain to this issue. In this particular case, the results and conclusions of the study provide significant information regarding the impact of various factors on hydrological modeling, which is important from the perspective of water resources management and environmental protection. We deeply believe that our analyses are of a scientific nature. We have put forward research hypotheses, verified them, discussed them against the backdrop of existing literature, and drawn conclusions from our analyses.

10. Reviewer comment:

Line 32: Episodes of constant, but less intense rainfall can cause flooding in hydrologically large watersheds. Please review. 

10. Authors answer:

We thank Reviewer for the comment. Because the Introduction has been rewritten, this sentence has been removed. We kindly ask to see Introduction, revised manuscript.

11. Reviewer comment:

Figure 1 does not account for the characteristics of the watershed, it is disjointed with the proposed scales of analysis. Perhaps a map of the watershed with land use coverages or a digital elevation model. Insert coordinate system, place names.

11. Authors answer:

We thank Reviewer for the comment. The figure 1 has been corrected. We kindly ask to see revised manuscript, fig. 1.

Reviewer 4 Report

Comments and Suggestions for Authors

Sustainability-2959493

Title: Urban flood modeling for sustainability management: role of 2

design rainfall and land use

Authors : Dariusz Młyński, Wiktor Halecki and Karolina Surowiec

 

Main comments:

The study is to investigate the role of design rainfall and land use on urban flood hydrograph. The manuscript is well written, however, the main concern is no innovative methodologies were introduced or applied in the paper. The manuscript is more likely a case study or a general research paper. For examples,

1)     Line 92-93, this may be true for the study area in this paper, but it is not true for most watersheds in USA.

2)     Line 97-99, this is not always true since lots of projects require 2D hydrological analysis, which always consider high resolution land cover and land use data as an important input.

Minor comments:

1)     Table 4 can be written as the text and Table 8 can be included on Figure 7 easily.

2)     Fig. 5, PIII is hard to find from the figure.

 

Author Response

1. Reviewer comment:

The study is to investigate the role of design rainfall and land use on urban flood hydrograph. The manuscript is well written, however, the main concern is no innovative methodologies were introduced or applied in the paper. The manuscript is more likely a case study or a general research paper.

1. Authors answer:

At the very beginning, we want to thank the Reviewer for the time spent reviewing our manuscript. We are grateful for their overall positive assessment. We agree with the Reviewer that the presented methodology is already known. However, in our work, we addressed problems that have not been analyzed before. We answered the question of how the selection of statistical distributions for estimating design rainfall affects the characteristics of design hydrographs. Additionally, we demonstrated the main advantages of the Urban Atlas database for defining land use structure. This database has not been used in hydrological analyses before. We deeply believe that our results can have broad practical applications because we recommend, based on the analyses, methods for determining design rainfall and land use in the catchment area.

2. Reviewer comment:

Line 92-93, this may be true for the study area in this paper, but it is not true for most watersheds in USA.

2. Authors answer:

We thank Reviewer for the comments. The sentence was replaced with: ‘Currently, there are many methods available for determining design rainfall depths and defining the land use structure of catchments’. We kindly ask to see revised manuscript, pg. 3.

3. Reviewer comment:

Line 97-99, this is not always true since lots of projects require 2D hydrological analysis, which always consider high resolution land cover and land use data as an important input.

3. Authors answer:

We thank Reviewer for the comment. We specified more precisely what is novel in our analyses. ‘In the presented research, the question of how design rainfall heights, obtained from various distributions, affect the characteristics of design hydrographs was addressed. Additionally, the possibility of using the Urban Atlas to determine the land use structure of the watershed was investigated. This database has not been previously utilized in similar hydrological analyses, which constitutes a novelty in the conducted research’. We kindly ask to see revised manuscript, pg. 3.

4. Reviewer comment:

Table 4 can be written as the text and Table 8 can be included on Figure 7 easily.

4. Authors answer:

We thank the Reviewer for the comment. We attempted to present Table 4 in text form and to display the values from Table 8 in the figure. However, after such conversion, this information became less readable. In Table 4, we presented a comparison for CN between individual years and land uses. In Table 8, characteristics of design hydrographs were compared depending on the applied land use base. As the numbering for Table 8 has been corrected, it is now Table 6. Generally, the results are more readable in the presented tabular form.

5. Reviewer comment:

Fig. 5, PIII is hard to find from the figure.

5. Authors answer:

We thank the Reviewer for the comment. We agree that the course of the design hydrograph for PIII overlaps with others, primarily with the Weibull distribution. This is because the design rainfall amounts for both distributions are practically the same (a difference of 0.1 mm). Therefore, the course of the design hydrographs for these distributions is practically the same, hence the overlap. Unfortunately, it is very difficult to correct this on the graph, which is why the characteristics of the design hydrographs are presented in Table 5.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

thank you for accepting my suggestions. I believe that it contributed to better comprehensibility and quality of the paper.