Glacial Lake Outburst Flood Monitoring and Modeling through Integrating Multiple Remote Sensing Methods and HEC-RAS
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors- Introduction does not explain how your work is different and significant from previous studies based on the literature review you have done? which gap you are trying to fill.
-Please find the comments in the PDF file.
Comments for author File: 
Comments.pdf
It requires minor edits especially for Introduction.
Author Response
Please see attached document.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsComments are attatched in PDF file.
Comments for author File: Comments.pdf
It is recommended to improve English.
Author Response
Please see attached document.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsDear authors,
The paper aims to analyze the hazard of Galong Co in terms of atmospheric factors, lake size, glacier thickness change, glacier avalanche potential, and dam stability, using multiple remote sensing data and methods. Secondly, to simulate the future hazard of Galong Co under three different simulated scenarios using HEC-RAS model. But here, most of the of those issues were just monitored and not evaluated, except the atmospheric (climatic) and avalanches factors as the real hazards. Thus, the main objective is to evaluate the flooding for the potential avalanches with consequences for the dam and the infrastructure at the outlet system. The view should be congruent between the abstract, objectives and conclusions. Beside several remote sensing input data used, some hydraulic parameters are not properly evaluated, either the calibration phase of the modelling. The paper has great challenges and very contributory, but still it needs to be reorganized; so at this stage is not publishable yet.
Line 23 – I think to put the whole meaning for the acronym of HEC RAS (Hydrologic Engineering Centre-River Analysis System) is not appropriate in this part.
Lines 56-58. As in above are defined the several parameters used for the modelling, here each remote sensing data sets, I guess could be valuable to relate with each one to those parameters, as it in below for InSAR I defined (The synergy of multiple remote sensing datasets, such as Synthetic Aperture Radar (SAR), Digital Elevation Mission (DEM), and optical images, allows us to better analyze GLOF processes)
Line 102 – Describe the acronym of HEC RAS
Line 101 – Which scenarios?
Lines 102-108. Those lines seem part of the methodology but not as objectives, or?
Line 115- 8021 above sea level?
Line 122- Rainfall or snow?
Line 171 – I guess the DEM accuracy data es crucial for the modelling, and here what is the error?
Line 182 – Where placed the stations?
Line 186 – increase of rainfall by 53.9 mm per decade is it correct? Also, does it include the snow?
Line 198- Maybe just based on HEC RAS
Line 205- Only one equation of V=f(A) ? The study focused on two glacial lakes, Galong Co (28.32°N, 85.85°E) and Gangxi Co 114 (28.35°N, 85.88°E)
Line 240- The manning how was calibrated and as only one value for the whole system?
Line 229- I think is missed the description and how was set up the HER RAS in more detail, for instance, the geometry information is missed. It was use the rasmaper tool?. How were defined the initial conditions. The HEC RAS was calibrated or just it was run?
Line 430 – Why the GLOF modelling is not included in chapter 4?
Line 30- Then the modelling for the second lake was not included?
Line 457 – The discharge values differ from values in Table 3.
Lines 540-542 Then was not evaluated the solid discharge? In addition, we conducted flooding modelling of Galong Co to evaluate the flow depth, flow discharge and time-series process, considering different release volumes and dam breach hydrography
Author Response
Please see attached document.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsInformation on risk at transboundary scale still missing
Precipitation is measurement of rainfall and snowfall, please be clear on this.
Author Response
Ref.:
We thank you very much for the constructive and helpful comments from the anonymous reviewer. We have made revisions based on the reviewer’s suggestions. The following are the detailed responses to the comments and suggestions item by item. Line numbers used in the reply section refer to the text in the revised manuscript.
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Reviewer 2:
Comments and Suggestions
Information on risk at transboundary scale still missing.
>> Thank you so much for your comments. We have made revisions to enhance the discussion on transboundary risk. We have expanded the discussion on the potential consequences of transboundary risks, including the social and economic impacts. We also emphasized the need for collaborative efforts among nations to mitigate and manage these risks effectively in the section 4.6. Please see below in L547-556:
“In the downstream reach to the border, where there are few buildings along the riverbank, the main threat is the 38-km-long cross-country highway (Allen et al.,2022). Although the flood we modeled did not extend to the border due to the limited coverage of the required high-resolution HMA DEM, previous studies have shown that the proportion affected by high-intensity flooding is 40% in Nepal, and the potential property losses up to over USD 197 million in downstream communities of Nepal from this GLOF (Wang et al., 2018; Cook et al., 2018; Allen et al.,2022). Glacial lake flooding from Galong Co poses a significant risk to Nepalese communities, hydropower stations, and other infrastructure along the Bhote Koshi River (Allen et al.,2022). Hence, collaborative efforts among nations are needed to mitigate and manage transboundary risks from the GLOF hazard.”
Precipitation is measurement of rainfall and snowfall, please be clear on this.
>> Thank you very much for the reminder. We have checked carefully this description in the text.
References:
Wang, W.; Gao, Y.; Anacona, P.I.; Lei, Y.; Xiang, Y.; Zhang, G.; Li, S.; Lu, A. Integrated hazard assessment of Cirenmaco glacial lake in Zhangzangbo valley, Central Himalayas. Geomorphology 2018, 306, 292-305.
Cook, K.L.; Andermann, C.; Gimbert, F.; Adhikari, B.R.; Hovius, N. Glacial lake outburst floods as drivers of fluvial erosion in the Himalaya. Science 2018, 362, 53-57.
Allen, S.K.; Sattar, A.; King, O.; Zhang, G.; Bhattacharya, A.; Yao, T.; Bolch, T. Glacial lake outburst flood hazard under current and future conditions: worst-case scenarios in a transboundary Himalayan basin. Natural Hazards and Earth System Sciences 2022, 22, 3765-3785.
