Spatiotemporal Projections of Precipitation in the Lancang–Mekong River Basin Based on CMIP6 Models
, Yanli Liu 2,3,4,5, Jianyun Zhang 1,2,*, Hua Chen 1, Junliang Jin 2,3,4, Cuishan Liu 2,3,4, Guoqing Wang 2,3,4 and Liushan Tang 2
Round 1
Reviewer 1 Report
In this article, the authors use 19 model outputs from CMIP6 and the MSWEP gridded precipitation dataset to simulate and predict future precipitation in The Lancang-Mekong River Basin. After correcting and integrating the model offsets, the authors analyzed the future precipitation trends, seasonal changes in precipitation characteristics, structural changes in the composition of daily precipitation, and spatial distribution of precipitation under the four future scenarios for the near-future (2030-2060) and the far-future (2060-2090) time periods, and came up with a series of conclusions on various aspects of future precipitation projections for the region.
If I understand correctly, let's move on to the questions:
There are instances in the article where the textual presentation does not correspond to the numbering of the pictures: 4.2 the first paragraph describes the contents of figure 5 but gives it as figure 7; 4.3 the first paragraph describes figure 8 but gives it as figure 9; 4.5 the second paragraph describes the contents of figure 12 but gives it as figure 13.
There are problems with the numbering of the pictures in the article. In the fifth part of the article, picture 14 is incorrectly numbered as picture 1; in addition, some of the pictures in the article are small size, making it difficult to see some of the contents clearly, for example, figures 2, 5 and 10.
In the second paragraph of 2.1, the region is divided into four regions in the basis of precipitation distribution and topography, but only the differences in precipitation among the four regions are reflected in the content, and the differences in topography among the four regions are not analyzed.
The third paragraph of 3.1 merely suggests that a threshold needs to be established for each month's precipitation data, without explaining how to obtain a suitable threshold.
The second paragraph of 4.2 is insufficiently substantiated by the fact that regional differences in precipitation will increase in the future based on the mere fact that regions with high future growth rates cover regions with high precipitation in previous years.
4.3 The conclusions of the analysis of precipitation in the fourth paragraph of the article are not evident in figure 9 and the conclusions of the analysis are not effectively supported.
The concept of CMIP6 is used several times in the article without specific explanation, and the authors should add some explanatory text where the concept first appears.
Minor editing of English language required
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Review of “Projection on precipitation in Lancang-Mekong River Basin Based on CMIP6 Models” by Zhouliang SUN et al.
In this manuscript, CMIP6 climate models are used to project future precipitation trends in the Lancang-Mekong River Basin (LMRB). In the study, the application of daily bias correction (DBC) is employed for the correction of simulation results, and then the Bayesian model averaging (BMA) method is used to ensemble the simulation of each model. Evaluation results indicate that the performance of the ensemble precipitation simulations surpasses that of individual models. The authors also underscore significant findings such as the increased ratio of wet season precipitation to dry season precipitation.
Based on the content presented in the manuscript, I believe this article holds substantial value in comprehending the implications of future precipitation changes in the Lancang-Mekong River Basin. However, this paper focuses on evaluating the performance of CMIP6 models, and it would be better if there is a certain mechanism analysis. In addition, there are many errors in the manuscript.
I recommend a major revision of the manuscript before considering publication.
Major Comments:
Page 1-3: I think the introduction part can be a little more concise, and the previous research on the region with observation and model data can be classified and stated for different spatio-temporal trends, so that the content will be clearer.
Page 5: What are the differences between the four SSP scenarios?
Figure 2: I'm curious about the reason for the large bias in simulation results for these models. What is the reference data for the simulated bias in Figure 2, is it MSWEP? As for the overestimated models that mainly occur in the upper LMRB, besides what you mentioned, there should be INM5, right? In addition, it is recommended to mark the R1, R2, R3, and R4 regions in each figure. Models’ names in the figure should be abbreviated to correspond to the analysis part.
Page 12: Is there any basis for saying that the increase rate of annual precipitation increases with the increase of radiative forcing?
Page 21: For the description of Figure 12, it was wrongly written as Figure 13 in the manuscript, and there are many similar problems. Also, are the descriptions of L1 and L2 sure to be correct? What I see from the Figure 12(a) is that L2 but not L1 does not change significantly. And why are there two L1 lines in Figure 12(b)?
In the paper, the authors present the simulation results of 19 models. But as far as I know, there are Community IntegrIated Earth System Model (CIESM), CAS-ESM1-0, etc. participating in CMIP6 in China. The authors can provide a brief introduction to these models and possible implications for the results. Here I list a closely-related article for your consideration as a reference:
Lin, Y., et al. (2020). Community integrated earth system model (CIESM): Description and evaluation. J. Adv. Model. Earth Syst., 12(8), e2019MS002036.
Minor Comments:
Page 2: “station meteorological data” should be “meteorological station data”.
Page 2-3: Please use a consistent citation format, for example, “GUO” should be “Guo”.
Page 3: What is the whole process of CHIRPS?
Page 3: “CMIP6 model” and “CMIP5 model” should be “CMIP6 models” and “CMIP5 models”.
Page 3: “Yamauchi et al” should be “Yamauchi et al.”.
Page 7: “formula” should be “formulas”.
Page 7: To explain what P and T mean. Please review the entire text to confirm whether each component in the formulas has been explained.
Page 7: There are cases where the characters in the explanation part are inconsistent with the fonts used in the corresponding formulas, such as Q.
Page 7: “where:” should be “where”.
Page 7: What is the meaning of p(fk|D), is it the posterior probability of the kth member model fk given the observed data D, or the weight wk of BMA?
Page 11: Please explain the meaning of MME.
Page 12、14、21、25: “Figure 7” should be “Figure 5”, “Figure 9” should be “Figure 8”,.and “Figure 13” should be “Figure 12”, “Figure 1” should be “Figure 14”, Please check the full manuscript.
Page 13: The title of each figure should clearly explain every detail in the figure, such as Figure 5.
Page 14: “Annual cycle of average monthly precipitation” should be “Annual cycle of average seasonal precipitation”.
Page 16: I don't see a decreasing trend in southern R1 under SSP585 in Figure 8.
Page 16: The legend in Figure 9 obscures a portion of the information, and the title of the figure should read (May-October) instead of (June-October).
Page 17: Please unify WDR in Figure 10 to Rwd.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
The authors have properly revised the manuscript.
