Large-Scale Flood Hazard Monitoring and Impact Assessment on Landscape: Representative Case Study in India

Round 1

Reviewer 1 Report

What is the technical conclusion in engineering for this study?. It would be better if authors consider the main conclusion of this study and add here just a sentence in abstract.

As a reviewer, I would like to state the fact that it should be supplied with more hydrological data.  

According to the researchers, floods were the deadliest natural hazard between 1995 and 2015, with an estimated 2.3 billion lives lost is this correct or not?  in line 56.  it is a huge value. Please check it.

According to the proposal, the important rivers in Assam are the Brahmaputra, Subansiri, Bhogdoi, Barak, Kolong, Dhansiri, Manas, etc. I think it should be given their annual discharges. It would better if the their annual discharges are given for two period sets such as values in monsoon period and values in outside of monsoon period.  There are lack of data in hydrology.

What is the scientific conclusion for this study.

There are so many revisions to be considered by authors. Those have been remarked on the text.

 

Comments for author File: Comments.pdf

Author Response

Reviewer 1

Comment 1: What is the technical conclusion in engineering for this study? It would be better if authors consider the main conclusion of this study and add here just a sentence in abstract.

Response: Thank you for your suggestion and comments. The authors have added the conclusion part in engineering for this study. Please check the abstract section for your reference.

Comment 2: As a reviewer, I would like to state the fact that it should be supplied with more hydrological data. 

Response: Thank you for your suggestion and comments. The authors have added more hydrological data for this study area. Please see the text for your reference. You can also see this in the introduction section.

The Ganga-Brahmaputra-Meghna River delta is an exceptionally fertile region that serves as a crucial river basin supporting crop production and vegetation. This expansive delta also encompasses vast areas impacted by natural disasters. For instance, the Brahmaputra River basin in Assam experiences the convergence of multiple tributaries, and the presence of suspended sediment and high river discharge poses significant risks to vegetation and crop production. Flood inundation in the study area results from multiple factors, including climate change, vegetation degradation, and the erosion of river banks. It is not only Assam that bears the brunt; other areas along the Brahmaputra River are also affected by the substantial river discharge.

Comment 3: According to the researchers, floods were the deadliest natural hazard between 1995 and 2015, with an estimated 2.3 billion lives lost is this correct or not? in line 56. it is a huge value. Please check it.

Response: Respected reviewer, Thank you for your suggestion. We agree with your comment. Please check the correction of this sentence.

According to researchers, floods were identified as the deadliest natural hazard between 1995 and 2015, affecting an estimated 2.3 billion people, with a recorded loss of 157,000 lives [10,11].

Comment 4: According to the proposal, the important rivers in Assam are the Brahmaputra, Subansiri, Bhogdoi, Barak, Kolong, Dhansiri, Manas, etc. I think it should be given their annual discharges. It would better if the their annual discharges are given for two period sets such as values in monsoon period and values in outside of monsoon period. There are lack of data in hydrology.

Response: Thank you for your comments and suggestion. The hydrological information is added in Table 1.

Comment 5: What is the scientific conclusion for this study.

Response: The conclusion is rewritten based on your suggestion and comments.

Comment 6: There are so many revisions to be considered by authors. Those have been remarked on the text.

Response: Thank you for your comments and suggestion. Please check all the corrections recommended by you. Several tables, figures and a substantial amount of text are rewritten and rearranged based on the comments.

Reviewer 2 Report

In this manuscript, remote sensing data acquisition and information processing technology are used to analyze and evaluate the flood range and its impact in Assam, India. The study itself is meaningful and useful. The structure of the paper is clear and the language is readable. However, there are some technical issues below for authors to respond. 

 

　　(1) Is 2.3billion after the first paragraph of the introduction accurate? That's a bit surprising, about a third of the world's population, right? Also, please state clearly whether this number is global or within India.

 　　(2) The 2nd Section should pay attention to the expression of geographical environment, geological environment, landform features and other relevant factors that have a direct relationship to the research object. It is unnecessary to mention information such as population literacy rate, which is not helpful to the research of this paper. Please pay attention to the scientific nature of the paper。

 

(3) The vegetation cover data in the study is based on the period from March to June. Is there any data deviation caused by the large area growth of seasonal crops or large area harvesting? How to exclude the influence of crop planting and harvesting on the results?

   (4) The paper should put forward corresponding suggestions based on the research results, such as the division of the area most prone to flood or the most serious impact, or the control of which river branch may have a certain promoting effect on reducing the extent or impact of flood.

Author Response

Reviewer 2

Comment 1: In this manuscript, remote sensing data acquisition and information processing technology are used to analyze and evaluate the flood range and its impact in Assam, India. The study itself is meaningful and useful. The structure of the paper is clear and the language is readable. However, there are some technical issues below for authors to respond.

Response: Thank you for your valuable comments and suggestion for this manuscript.  

Comment 2: (1) Is 2.3billion after the first paragraph of the introduction accurate? That's a bit surprising, about a third of the world's population, right? Also, please state clearly whether this number is global or within India.

Response: Respected reviewer, thank you for your comments, We have written this section. Please check the corrected sentence.

According to researchers, floods were identified as the deadliest natural hazard between 1995 and 2015, affecting an estimated 2.3 billion people, with a recorded loss of 157,000 lives [10,11].

Comment 3: (2) The 2nd Section should pay attention to the expression of geographical environment, geological environment, landform features and other relevant factors that have a direct relationship to the research object. It is unnecessary to mention information such as population literacy rate, which is not helpful to the research of this paper. Please pay attention to the scientific nature of the paper。

Response: Thank you for your suggestion and comments. Geology, geomorphology and landforms-related information have been updated in the introduction and study area section. Please check the modification of the research throughout the manuscript.

Comment 4: (3) The vegetation cover data in the study is based on the period from March to June. Is there any data deviation caused by the large area growth of seasonal crops or large area harvesting? How to exclude the influence of crop planting and harvesting on the results?

Response: Respected reviewer, thank you for your concern about the study. This manuscript investigated the vegetation, mainly forest, including dense forest and open forest change. Cropland or harvesting areas are not calculated in this manuscript. The thesolding values are used for this vegetation area detection. Therefore cropland areas are differenciate with the vegetation.

Comment 5: (4) The paper should put forward corresponding suggestions based on the research results, such as the division of the area most prone to flood or the most serious impact, or the control of which river branch may have a certain promoting effect on reducing the extent or impact of flood.

Response: Thank you for your suggestion. A discussion section has been added before the conclusion section. Please check this for your reference.

Reviewer 3 Report

Manuscript: sustainability-2439389-peer-review-v1

Large-scale flood hazard monitoring and impact assessment on 2 landscape: Representative case study in India

Summary:

The manuscript presents a study about a major flood in Assam, India, in 2022. The authors presented the analysis of the impact of the flood on land use and land cover areas, inundation areas, and deforested lands using information pre-flood and post-flood from Sentinel-1 C band GRD SAR data and the Google Earth Engine (GEE) cloud computing platform.

 

Overall opinion:

The subject addressed in the manuscript is of potential interest to researchers, regarding the methodology and analysis of the results, and decision makers, mainly regarding the management of the area under study. It also meets the publishing objectives of the journal.

However, in my opinion, the manuscript is not ready to be published and needs improvement before publication. It needs full revision and editing before publication regarding the English language and format. Parts of the text need to be clarified and organised to remove repeated ideas/text (a) and improve the flow of the text (b). As well, there are parts of the manuscript that need to be improved (c). Please find a few comments below.

 

Comments

a) repeated ideas/text:

Example: paragraphs on Lines 283-287, 355-358 (this information is not adequate to include in the conclusion section)

 

b) English format and grammar, confuse text – some examples:

Verbal forms are frequently inadequate and need revision.

Section 4.1 needs a deep revision of the text, it is difficult to understand.

Abbreviations at the beginning of the sentences: Lines 266, 327

LU/LC or LULC? Needs to be harmonised

 

c) discussion of the results needs to be improved

In the present form, there is no discussion of the results, it is mainly presented a description of the tables.

With the information presented it could be constructed a Map of Risk for the area, also a map or recommendations for intervention in the area.

The information on lines 355-358 is not adequate to include in the conclusion section. The Conclusion section must synthesise the major finds of the study, its applicability and, eventually, recommendations for future research.

The English language and format needs editing before publication, regarding the verbal forms and construction of sentences.

Author Response

Reviewer 3

Summary: The manuscript presents a study about a major flood in Assam, India, in 2022. The authors presented the analysis of the impact of the flood on land use and land cover areas, inundation areas, and deforested lands using information pre-flood and post-flood from Sentinel-1 C band GRD SAR data and the Google Earth Engine (GEE) cloud computing platform.

Comment 1: Overall opinion: The subject addressed in the manuscript is of potential interest to researchers, regarding the methodology and analysis of the results, and decision makers, mainly regarding the management of the area under study. It also meets the publishing objectives of the journal.

However, in my opinion, the manuscript is not ready to be published and needs improvement before publication. It needs full revision and editing before publication regarding the English language and format. Parts of the text need to be clarified and organised to remove repeated ideas/text (a) and improve the flow of the text (b). As well, there are parts of the manuscript that need to be improved (c). Please find a few comments below.

Response: Thank you for your suggestion and comments. We have modified the manuscript based on the comments.    

Comment 2: a) repeated ideas/text:

Example: paragraphs on Lines 283-287, 355-358 (this information is not adequate to include in the conclusion section)

Response: Thank you for your suggestion. This paragraph is modified and removed from the conclusion section. Please check the revised conclusion.  

Comment 3: b) English format and grammar, confuse text – some examples:

Verbal forms are frequently inadequate and need revision.

Section 4.1 needs a deep revision of the text, it is difficult to understand.

Abbreviations at the beginning of the sentences: Lines 266, 327

LU/LC or LULC? Needs to be harmonised

Response: Thank you for your suggestion and comments. We have modified the manuscript based on the comments.

Comment 4: c) discussion of the results needs to be improved

In the present form, there is no discussion of the results, it is mainly presented a description of the tables.

With the information presented it could be constructed a Map of Risk for the area, also a map or recommendations for intervention in the area.

Response: Thank you for your suggestion and comments. We have modified the manuscript based on the comments. A discussion section has been also added before the conclusion section. The authors agree that the risk map is more helpful in understanding the information. But our study focuses on real-time flood Inundation and vegetation change, while the risk map needs other criteria like runoff, geomorphology, and many others. Therefore, we just identified the real-time flood monitoring of our study.                

Comment 5: The information on lines 355-358 is not adequate to include in the conclusion section. The Conclusion section must synthesise the major finds of the study, its applicability and, eventually, recommendations for future research.

Response: Thank you for your suggestion and comments. We have modified the manuscript based on the comments. Line number 355-358 has been removed from the manuscript.   

Reviewer 4 Report

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Happy to read this article regarding “Large-scale flood hazard monitoring and impact assessment on landscape: Representative case study in India”. In general, this manuscript is well prepared. However, the following issues need to be addressed:

The abstract is very lengthy, and some unnecessary information is there, please rewrite the abstract. I suggest please summarize and not need to give general information; it should be specific. Please merge or remove from lines 28-35.

The main objective and significance of work is not explained in the introduction section. The Limitation of this study area also not mentioned.

The authors derive the change of inundation area over time during the 2022 flood. They use MNDWI and maximum likelihood supervised classification to distinguish between water and different land use/cover classes. I did not see any interesting dataset and method for accuracy assessment. The applied analysis techniques are standard and do not provide new aspects, but the authors successfully explicit the flooded areas. Data and methods are not clear, enlist it in a table. The accuracy assessment and validation of results should be separate section in methodology.

The results and discussion are mixed and hard to find the results. This results section is a very time-consuming review process. I suggest to separate them into 2 sections.

The figure 4 should be in large data frames instead of showing in sections.

In conclusion, the scientific contribution of this work should be exhibited. This is a basic study and currently have no new innovative aspect.

 

 

 

 

 

 

 

 

 

 

 

 

 

  Happy to read this article regarding “Large-scale flood hazard monitoring and impact assessment on landscape: Representative case study in India”. In general, this manuscript is well prepared. However, the following issues need to be addressed:

The abstract is very lengthy, and some unnecessary information is there, please rewrite the abstract. I suggest please summarize and not need to give general information; it should be specific. Please merge or remove from lines 28-35.

The main objective and significance of the work are not explained in the introduction section. The Limitation of this study area is also not mentioned.

The authors derive the change of inundation area overtime during the 2022 flood. They use MNDWI and maximum likelihood supervised classification to distinguish between water and different land use/cover classes. I did not see any interesting dataset or method for accuracy assessment. The applied analysis techniques are standard and do not provide new aspects, but the authors successfully explicit the flooded areas. Data and methods are not clear, enlist it in a table. The accuracy assessment and validation of results should be separate sections in the methodology.

The results and discussion are mixed and hard to find the results. This results section is a very time-consuming review process. I suggest separating them into 2 sections.

Figure 4 should be in large data frames instead of showing in sections.

In conclusion, the scientific contribution of this work should be exhibited. This is a basic study and currently has no new innovative aspect.

 

 

 

 

 

 

 

 

Author Response

Reviewer 4

Comment 1: Happy to read this article regarding “Large-scale flood hazard monitoring and impact assessment on landscape: Representative case study in India”. In general, this manuscript is well prepared. However, the following issues need to be addressed:

Response: Thank you for your positive suggestion and comments.

Comment 2: The abstract is very lengthy, and some unnecessary information is there, please rewrite the abstract. I suggest please summarize and not need to give general information; it should be specific. Please merge or remove from lines 28-35.

Response: Thank you for your suggestion and comments. The abstract section has been modified as per your suggestion.

Comment 3: The main objective and significance of work is not explained in the introduction section. The Limitation of this study area also not mentioned.

Response: Thank you for your suggestion and comments. The introduction and limitation section has been modified as per your suggestion.

Comment 4: The authors derive the change of inundation area over time during the 2022 flood. They use MNDWI and maximum likelihood supervised classification to distinguish between water and different land use/cover classes. I did not see any interesting dataset and method for accuracy assessment. The applied analysis techniques are standard and do not provide new aspects, but the authors successfully explicit the flooded areas. Data and methods are not clear, enlist it in a table. The accuracy assessment and validation of results should be separate section in methodology.

Response: Respected Reviewer, thank you for your suggestion and comments. We added the classification and other necessary information for this specific comment.       

Comment 5: The results and discussion are mixed and hard to find the results. This results section is a very time-consuming review process. I suggest to separate them into 2 sections.

Response: Thank you for your suggestion and comments. The result and discussion sections have been modified as per your suggestion.

Comment 6: The figure 4 should be in large data frames instead of showing in sections.

Response: Thank you for your suggestion and comments. Figure 4 has been modified as per your suggestion.

Comment 7: In conclusion, the scientific contribution of this work should be exhibited. This is a basic study and currently have no new innovative aspect.

Response: Thank you for your suggestion and comments. The conclusion section has been modified as per your suggestion.

 

 

 

Round 2

Reviewer 3 Report

Review on Manuscript Number: sustainability-2439389-peer-review-v2

“Large-scale flood hazard monitoring and impact assessment on 2 landscape: Representative case study in India”

 Comments on the Revised manuscript

During the reviewing process the authors clarified some of the issues raised by the reviewers and in this revised version of the manuscript adequate and important modifications were made. The quality of the manuscript was improved by the authors. However, the discussion of the results should have been improved and presented in a more scientific way. Also, before publication, the text needs editing to correct some minor typos and verbal forms in the text. I advise professional editing help.

In my opinion, before publication, the text needs editing to correct some minor typos and verbal forms in the text. I advise professional editing help.

Author Response

Comment 1: During the reviewing process the authors clarified some of the issues raised by the reviewers and in this revised version of the manuscript adequate and important modifications were made. The quality of the manuscript was improved by the authors. However, the discussion of the results should have been improved and presented in a more scientific way. Also, before publication, the text needs editing to correct some minor typos and verbal forms in the text. I advise professional editing help.

Response: Respected reviewer, thank you for your suggestion and comments on this manuscript. We are changes all the discussion section with the scientific contribution of this research. Please see the discussion section for your references.   

The main objectives or contribution of this investigation are to characterize the effects of the Assam flood that occurred in 2022 on land use and land cover areas, the inundation areas, and deforested lands, using Sentinel-1 C band GRD SAR data and GEE cloud computing platform. This analysis is essential for the inundation measurement with the vegetation-damaged area identification with the help of high-resolution microwave SAR datasets, which is more impactful for vegetation health and flood hazard monitoring during floods. Real-time flood monitoring of the recent Assam flood has huge damage recorded. Therefore, identification of the hazard areas and vegetation damage might help in future disaster management and awareness to protect the hazard areas. This study's outcomes (2022 Assam Flood) are not previously examined; therefore this analysis might help a lot for future decision-making and awareness to protect the flood inundation. Also, the vegetation-damaged location helps to prepare novel adaptation strategies to protect the forested lands, which is essential to environmental protection. The results of this investigation might support local planners, administrators, researchers, and management departments to protect life and help them in post-disaster planning in Assam state.

The Assam is mainly a flood susceptible state. Future, the predictable intensification of the rainfall, its strength and enhanced summer flows might lead to additional frequent incidences of the flood and flash flood in the Assam’s Brahmaputra river valley [48]. The uneasiness in India that great flood susceptible areas suffer additional from the homelessness difficulties. Somewhat high flood prone regions people have lesser poverty incidence and higher spending [49]. Meanwhile continuous SAR datasets can be developed throughout the flood because of the lengthier wavelength accompanied by its sensitivity near geometrical, dielectric, and structural possessions of the target, flood inundation diagrams have been produced by dual-polarized Sentinel-1 SAR datasets [50]. The conceivable clarification might be fewer agriculturalists, additional administration relief, and better of scheduled tribe with elevated substance in the high flood prone regions. From the previous conversation researchers find that flood varieties people susceptible to the poverty. Conversely, poor people and those existing in highly flood prone regions are additional susceptible to the flood hazard [48].  

Comment 2: In my opinion, before publication, the text needs editing to correct some minor typos and verbal forms in the text. I advise professional editing help.

Response: The entire manuscript was checked with respect to language, technicality, and grammar errors. We did not keep track change as all the manuscript was revised.

Reviewer 4 Report

I am happy to see the revised version of the manuscript. However, the authors have accepted my suggestions partially. They have made changes in some sections. But I think still there is a lack of scientific contribution and innovation in this work. I again utterly suggest to the authors that please exhibit your innovative aspects in the conclusion section. 

Author Response

Comment 1: I am happy to see the revised version of the manuscript. However, the authors have accepted my suggestions partially. They have made changes in some sections. But I think still there is a lack of scientific contribution and innovation in this work. I again utterly suggest to the authors that please exhibit your innovative aspects in the conclusion section.

Response: Respected reviewer, thank you for your suggestion and comments on this manuscript. We are changes all the discussion section with the scientific contribution of this research. Please see the discussion section for your references.

The scientific contribution of this research is to find out flood inundation with the vegetation damaged area identification of the 2022 Assam flood, which is very much important to identifying the hazard vulnerability using Sentinel -1 SAR datasets and GEE platform. We find that the state Assam flood have more affected in the side of the Brahmaputra River while forest areas are mostly affected due to the flood hazard. This study is recent advantage which is not previously examining recent 2022 flood hazard. Therefore, this contribution have more essential for hazard venerability assessment.

We look forward to hearing from you in due time regarding our submission and to respond to any further questions and comments you may have.