Research on Jianghan Plain Water System Dynamics and Influences with Multiple Landsat Satellites

Comments 1: Acronyms: 1. A list of acronyms is needed; I do not know if it is a Journal requirement or not. But it will be easy to have it.

Response 1: Thank you for pointing this out. We agree with this comment.Based on all the abbreviations in the article, I have created a table as shown in Table 5, line 665.

Comments 2: Abstract Improvement: The abstract can be improved both in terms of writing and content. For instance, lines 25-28 need clarification and enhancement.

Response 2: We have corrected some grammar errors. Please refer to lines 8-29 for detailed modifications.

Comments 3: Writing Issues: The manuscript contains numerous writing issues, making it difficult to grasp the authors' meaning. For example, the term "10a" on line 55 and "pixel_qa" on line 181 are unclear. Sentences in lines 89-97 are long and need to be broken down for clarity. The term "star sources" on line 198 is ambiguous. There are many missing periods, such as on line 141. Use of semicolons and other punctuation errors are frequent, particularly between lines 153-163. The manuscript should be thoroughly checked for grammatical and punctuation errors, including on line 263.

Response 3: Thank you for your suggestion. We have read the entire text and corrected grammar, comma, and word errors. For some unfamiliar vocabulary, other meanings have also been expressed. We have also conducted a detailed review and optimization of your English revision suggestions, such as the abstract section, punctuation section, and long sentence section.

Comments 4: Citation Format: The citation format is inconsistent and incorrectly applied, as seen on line 71. Citations are missing in several places, such as lines 130-131, 227-230, 396-398, and many others. Citations should be added wherever necessary.

Response 4:We have standardized the format of the citations, as shown in lines 74-93.

Comments 5: Figure 1: Figure 1 is poorly drawn and lacks context about its location within China and neighboring regions. It should be improved, possibly by showing some watersheds or lakes.

Response 5:For Figure 1, we have added water bodies and administrative boundaries of Hubei Province to make it more intuitive, as shown in lines 132-134.

Comments 6: Figure 2: Figure 2 is crucial but needs improvement to enhance its readability and comprehension.

Response 6：We have also updated and improved Figure 2, providing explanations and clarifications for some unclear areas; Deleted redundant and repetitive content, and provided explanations for the "merge" and "Exponential equalization" operations, as shown in line 208.

Comments 7: Table 2 Reference: Line 312 needs to be checked. Table 2?

Response 7:Thank you for pointing this out. We agree with this comment.The reference to Table 2 in line 312 is indeed incorrect. Table 2 does not specify PA and UA, and in fact, the confusion matrix does not need to be explained in the paper. Therefore, I have deleted this sentence.

Comments 8: Notation Clarity: Exact notations used in the formulas should be clearly written, as seen in lines 315-317.

Response 8:We have placed the references to formulas 3 and 4 in the correct positions. See lines 305-307.

Comments 9: Clarity in Discussion: Lines 342-345 are confusing and require a more detailed discussion for better understanding.

Response 9:There was a bit of confusion in the description of method validation, so we have rephrased it in more concise language. Please refer to lines 314-347 for specific modifications. See lines 337-342.

Comments 10: Table Reference: When referring to "mentioned above," specify the table number for clarity.

Response 10:We have cited the specific number for the "mentioned above" in line 360 and ensured that there are no other related errors throughout the entire text.

Comments 11: Figure 4: Figure 4 is difficult to understand. Clarify what it is intended to show.

Response 11:We have provided explanations for each subgraph in Figure 4(Now it is Figure 6), hoping to help readers understand. See lines 379-384.

Comments 12: Year Specification: On lines 375-376, specifying the year would help readers follow along in the figure.

Response 12:We have added a description of the year in the subgraph legend. See lines 379-384.

Comments 13: Data Accuracy: On line 381, the statement about the range in 2016 and 2020 should be verified. It does not appear that these years have significantly larger ranges.

Response 13: We have added a line chart of the water area in the Jianghan Plain over the past 20 years, which shows that there were indeed large water areas in 2016 and 2020. See Figure 8, line 405. Additionally, a comparison chart of water system changes in the Jianghan Plain from 2002 to 2021 has been added to verify the water system changes in the Jianghan Plain spanning 20 years, namely the increase and decrease of water bodies. See line 406. Additionally, line 4.1.1 in 386 provides an explanation of the overall spatiotemporal characteristics, which are detailed in section 4.1.2 (lines 441-449) for the analysis of water systems in 2016 and 2020.

Comments 14: Figure 6: Figure 6 is difficult to understand and needs improvement.

Response 14: Regarding Figure 6 (now Figure 10), we previously standardized all data units for aesthetic purposes, but this caused difficulties in data observation. Therefore, we explained the normalization of data units and displayed rainfall as a line. See line 449.

Comments 15: Sentence Length: Lines 426-431 contain very long sentences that need to be rewritten for clarity.

Response 15:We have corrected some grammar errors and removed some content to make the long sentence shorter.

Comments 16: Figure 9: Figure 9 is unclear and needs to be improved.

Response 16:The water landscape index in Figure 9 (now Figure 14) is very small, and separating it from the thematic map can make the image clearer. See lines 510-513.

Comments 17:  Figure Captions: The caption for Figure 10 is at the top, but it is standard practice to place figure captions below the figure.

Response 17:We have adjusted the subheadings of Figure 10 (now Figure 15). See lines 533-535.

Comments 18: Figure 12: Figure 12 lacks a legend, making it unclear which rivers are represented.

Response 18:For Figure 12 (now Figure 17), we have highlighted the river, made corrections using ArcGIS, and added a legend to provide a more intuitive understanding of the relationship between the water system and the building area.See line 592.

Comments 19: Discussion Comparison: The results and discussion section should compare the findings with other studies. Currently, there is a lack of comparison with existing literature.

Response 19:We have added some literature in the Results and Analysis section to validate our results and hypotheses, lines 396-397 and 586-588.

Please see the attachment.

Comments 1: The Fig.2 is not clear enough, NDVI/Normalized Difference Vegetation Index, MDNWI/ Modified Normalized Difference Water Index, EVI/Enhanced Vegetation Index are same, are not necessary to be shown twice; In my opinion, L5water, L7water and L8water were used to extract initial water body in difference years, the "merge" process is inexplicable, with text in line 267-269.

Response 1: Thank you for pointing this out. We have also updated and improved Figure 2, providing explanations and clarifications for some unclear areas; Deleted redundant and repetitive content, and provided explanations for the "merge" and "Exponential equalization" operations, as shown in line 208.

Comments 2: Formula 2 is empirical, is it suit for other regions?

Response 2: We also provide the scope of application of Formula 2 in the explanation of Formula 2, as shown in lines 258-260.

Comments 3:  The threshold for Pwater was set to 0.4, many seasonal water bodies would be omitted, i think it's adverse to flood identification.

Response 3: Thank you for your suggestion. The 0.4 threshold is relatively accurate in distinguishing between water bodies and non water bodies. During flood periods, when water bodies are turbid, the sensitivity of the threshold will decrease, and it may not be as accurate in distinguishing water land boundaries. However, for interannual water body extraction, it can still accurately reflect flood years. We are considering the water bodies of the entire year, and a threshold of 0.4 has a certain probability of excluding seasonal water bodies. However, there is no problem with extracting and analyzing water bodies from the final interannual data.

Comments 4: It's hard to get useful information from Fig.5, same as Fig.12.

Response 4:For Figure 5 (now Figure 9, lines 408-417), we have added a line chart of the water area of the Jianghan Plain over the past 20 years. It can be seen that there were indeed large water areas in 2016 and 2020. Refer to Figure 7,. At the same time, a comparison chart of water system changes in the Jianghan Plain from 2002 to 2021 was added to verify the water system changes in the Jianghan Plain spanning 20 years. For Figure 12 (now Figure 17, lines 592-594), we have highlighted the river, made corrections using ArcGIS, and added a legend to provide a more intuitive understanding of the relationship between the water system and the building area.

Comments 5:  Line 263, "asa" should be "as a".

Response 5:We have also made corrections to the English editing errors you raised.

Comments 6: There are many research papers on water extraction based on remote sensing, and it is recommended to add citations, summarize and analyze them to reflect the innovative of this study.

Response 6：There are some studies on water extraction methods in the original text, and we have added some, see 46-68.

Comments 7: You compared the accuracy of three other approaches to mapping the water resources of the Jianghan Plain (the JRC dataset, using the SDWI index, and something you referred to as "Landsat-8 permanent water bodies" to the accuracy of the Landsat-5, -7 and -8 multi-index fusion threshold method. However, your methods section did not describe the SDWI nor the "Landsat-8 permanent water bodies" methods. This is a serious omission, which must be corrected.

Response 7:We have added descriptions of SDWI, JRC, and Landsat8 permanent water extraction methods. See 320-336.

Please see the attachment.

Comments 1: Your accuracy validation method described in section 3.3.2 is TOTALLY INAPPROPRIATE! Firstly, the methods used are poorly described. Secondly, using the "median image of Landsat 8" (whatever that is - it was not described) along with single-band images from Sentinel-1 and -2 (also never described - which band and why only one band) to select 100 water bodies and 50 non-water features adds an unknown, but likely large, amount of uncertainty to your reference data set. YOUR WHOLE ACCURACY EVALUATION METHOD NEEDS TO BE RE-DONE WITH A REFERENCE DATA SET OF KNOWN CERTAINTY, SINCE REFERENCE DATA SETS ARE ASSUMED TO BE NEARLY 100% ACCURATE.

Response 1: Thank you for your suggestion. We actually need to verify the accuracy of water extraction from 2002 to 2021. As Landsat 8, Sentinel-1, and Sentinel-2 do not have images spanning 20 years, I used these three actual images as the base maps for sampling points for verification. We used manual sampling to select a total of 1000 water sampling points and 500 non water sampling points, which is absolutely correct. Therefore, the accuracy verification method is relatively reliable. Please refer to lines 337-342 for specific modifications.

Comments 2: .Figures 5, 6, 7, 9, and 12 all need major revisions or explanations.

Response 2: Based on your suggestion, we have added bar charts for the Jianghan Plain water area, Changhu area, and Honghu area to Figure 5 (now Figure 9, lines 408-417), which helps to visually observe changes in water area over a long period of time. The modifications to Figure 6(now Figure 10, See line 449) and Figure 7(now Figure 12, line 459) were originally made to unify all data units for aesthetic purposes, using stacked line charts. However, this caused difficulties in observing the data and prevented the display of real data. Therefore, we scaled the data and added secondary coordinate axes to display the real data on the chart without causing misunderstandings. The original line chart in Figure 9((now Figure 14, See lines 510-513) was too small to clearly see and analyze the data. We separated it for better observation. For Figure 12 (now Figure 17, lines 592-594), we have highlighted the river, made corrections using ArcGIS, and added a legend to provide a more intuitive understanding of the relationship between the water system and the building area.

Comments 3: Refer to the attached pdf document for all of my edits, comments and suggestions.

Response 3: Thank you for your valuable suggestion. Based on the PDF file you provided, the modifications made are as follows:

Please see the attachment.

Comments 1: The abstract still needs improvement to meet publication standards.

Response 1: Thank you for pointing out this out. We have restructured the abstract and listed the conclusions by point, please refer to lines 8-27.

Comments 2: The introduction is not promising, and the flow is not good, particularly in the first paragraph.

Response 2:Thank you for your suggestion. Each paragraph in the previous introduction was separate, and I have added transitional sentences before each paragraph in the introduction section. And reconstructed the first and last paragraphs. Please refer to lines 32-109 for details.

Comments 3: Wherever acronyms are used for the first time, please define them before using them later in the manuscript.

Response 3:Some abbreviations in the original text were not defined when they first appeared, such as JRC (line 64), SR (line 138), Dynamic World (line 143), Google Earth Engine (line 114), the Synthetic Aperture Radar (SAR) Wetland Detection Index (SDWI) (line 312), Vertical Horizontal (VH) and Vertical Vertical (VV) (line 321), and Land Surface Water Index (LSWI) (line 328).

Comments 4: The manuscript still has numerous writing issues, such as missing periods, capital letters, etc. Please review the manuscript in detail to eliminate these minor errors.

Response 4:Thank you very much for your reminder. We have rechecked the entire text and found that some places did not add periods after citing references, and the first letter of the last sentence is not capitalized. After correction, no issues were found.

Comments 5: In many places, citations are missing. For instance, in lines 118-119, where did you get this data? Did you measure it yourself? If you are using other people's work, you need to provide citations. The same applies to lines 222-223 and many other places.

Response 5:I completely agree with your opinion. Some parts were not cited. Regarding the data found online and in literature, we have added new citations, as shown in line 115, line 204, line 214, line 218, line 221, line 352, line 603.

Comments 6: For Table 1, please provide a link to the source.

Response 6:We have added a column in Table 1 to store the source links of the data. See line 149.

Comments 7: When mentioning a figure or table in the manuscript, I see just the caption. Please discuss the figure or table in a few lines.

Response 7:We fully agree with your opinion, therefore, we have added explanations for Figure 12 (lines 460-462), Figure 13 (lines 477-478), Figure 14 (lines 478-480), Figure 15 (lines 521-522), Figure 16 (lines 578-579), Figure 18 (lines 610-611), Figure 19 (lines 616-618), and Table 4 (lines 579-580).

Comments 8:Exact notations used in the formulas should be clearly written. As seen in lines 306-309, the notations look similar but are still different.

Response 8:Thank you very much for your suggestion. The original text did not use formulas to represent symbols, which resulted in inconsistent symbols. We have made the necessary modifications. See lines 306-309.

Please see the attachment.

Comments 1: The authors have answered all my comments and improved the manuscript. However some figures could perform better, for example, in "Figure 19. The distribution of the distance between Changhu and Honghu and the city center", the figure title is confused, I think there are 2 example, subtitle (a) (b) could be used, and the "city center" should be marked, two distance "to lake" and "to the Yangtze River" could be described more clearly.

Response 1: Thank you very much for bringing this up. Based on your suggestion, we have made modifications and updates to Figure 19, and added subheadings to make its expression clearer. See lines 624-628.

 Please see the attachment.