Spatiotemporal Changes in Extreme Precipitation in China’s Pearl River Basin during 1951–2015
Round 1
Reviewer 1 Report (Previous Reviewer 1)
Authors did a great job of finalizing the manuscript. All my comments have been taken into account in the updated text of the paper. I can recommend an article for publication in a journal. The following are some minor remarks.
Line 146-147 Previous studies are noted, but no links to these studies
Line 534-535, 537-538, 545-546,552-553 The name of the data array is missing in the figure caption
Line 658, 684,755 Page numbers are incorrect
General comment on the text. A detailed description of the values of the linear trends of the indices is given, while they are mostly statistically insignificant. I recommend focusing on describing only statistically significant trend values.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report (Previous Reviewer 3)
The article “Spatiotemporal changes in extreme precipitation in China’s Pearl River basin during 1951-2015” with ID water-2492224 has already been submitted and evaluated with ID water-2310346. The new version of the article presents a significant improvement, both in scientific writing and in the presentation of new results and discussions (with highlights for the new sections 4.2 and 4.3, Figure 10, among others).
Therefore, the opinion is “accept as is”, with only a minor revision: Figures 6 and 7 should be improved in terms of font size, as they lose resolution with the increase in zoom when trying to see the images. color scale variations. (Figure 5 is better in this regard)
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report (New Reviewer)
None
The quality of English language used throughout the document could be improved upon, possibly with the assistance of an editor that solely focuses on that task.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
Reviewer’s comments
The manuscript aim is to analyze the spatiotemporal characteristics of extreme precipitation in the Pearl River Basin from 1951 to 2015. Overall, the manuscript is well structured. Generally, the analysis of precipitation averages and trends is difficult throughout the manuscript. Trend analysis should be focus only on significant values. There is need few minor corrects. Some other comments are listed below for further tuning the manuscript.
Line 60-72 I recommend indicating the time periods which used to the analyze precipitation. This will allow a more accurate comparison of the results obtained by other authors.
Line 123-127 The paragraph shows the characteristics of analyzed region. It is not clear whether the given results are obtained by the authors or from literary sources.
Line 244 -281 Describing annual trends, I recommend giving only significant values of the trend coefficients
Line 249 PD index description is missing from the table 1.
Line 283-284 According to the Methods section, the trend significance is evaluated for the 90th confidence level. Figure 2 caption indicates that the trend is significant at 0.05. Please provide clarifications
Line 286-287 The symbol * designation is missing in the Figure 3 caption. What is the second axis of ordinates for?
Line 307 Please check the figure link
Line 314 The symbol * designation is missing in the Figure 4 caption. Figures 4a-4d contain two trend lines, but one trend equation is shown. Please correct it
Line 346-349 Figure link is missing in this paragraph.
Line 352-353 Is Figure 5 show long-term averages or trend values? Figure 5 is of poor quality, and the scales are not readable.
Line 358-359 Why other indices were not analyzed?
Line 361-362 Are here we talking about the annual distribution or the annual trend?
Line 400 Is the figure 6 show the seasonal distribution of precipitation indices?
Line 402-403 The M-K test is often used to detect statistical significance of trends, but not to detect the spatiotemporal distribution of analyzed average values.
Line 441-442 The symbol * is missing in the Figure 7. Figure 7 resolution needs to be increased
Line 445-454 The paragraph presents the results of early studies without indicating the time period. This makes it difficult to compare results.
Line 475 The figure 8 demonstrates the time series of precipitation for two datasets and their trends. The figure 8 caption contains only the «trends»
Line 485-486 The figure 9 probably demonstrates spatial average precipitation for two datasets. But caption describes otherwise. The time period is not specified.
Line 520-528 Have assessment of the significance of correlations performed?
Reviewer 2 Report
Dear authors, I have reviewed your manuscript entitled: Spatiotemporal changes in extreme precipitation in China’s 2 Pearl River basin during 1951-2015. The proposed indexes are valid to achieve the objectives proposed in this study, as well as the statistical analyses carried out throughout the manuscript. In addition, it is possible to investigate changes in extreme precipitation with interpolated values of observations at 0.25º of horizontal resolution, but yourselves recommend using other databases involving other sources of data assimilation and high resolution. Indeed, Aphrodite use a high density of input stations, interpolation scheme, and quality control of data, but there are recommendations to be caution because the amount of input data varies in space and time, and the input data are not homogenized. Therefore, trend analyses and the characterization of extreme events should be performed with caution. Indeed, I think it is fine to compare Aphrodite data with CMA, but another database such as MSWEP (available from 1979 with a resolution of 0.1º) or CHIRPS (available from 1981 and a resolution of 0.05º) should have been used, since they have higher spatial resolution and involve not only observational data. In fact, again, this is an argument raised by the authors, the added value of databases with sources not only of observed data, especially for this region with such topographic changes. In addition, although it is not the main objective of the study, a spatial analysis could be added to the temporal analysis with the runoff in section 4.3. Additionally, read the minor comments below.
I have to reject this study in the present form. But my recommendation is to improve this study by adding the analysis of new datasets I mentioned above, improve the discussion, and resubmit. This decision is based on the importance of publishing articles with stronger scientific content and therefore quality!
Minor comments
Lines 39-40. Please check these sentences. How is that change of precipitation patterns will lead to ‘tropical cyclones’? Perhaps sounds better to mention first the heavy rainfall and later the floods, to be consequent.
Line 42. ‘Recent studies’ but you only have just one reference, the [6].
Line 79. ‘The resultant extreme water events’ you mean ‘extreme precipitation events’? or do you want to express other condition related with water?
Line 80. …. ‘and river ecosystem’ Please add that it is also for Pearl river basin.
Line 80. The runoff is not also modulated by precipitation, but of course is the key factor. The type of soil, and the land cover and its changes can also modify the normal runoff patterns.
Lines 82-83. The ideas do not seem to be very well connected between the sentence on runoff and the following one that returns to the subject of extreme precipitation.
Line 87. ‘Duan et al. [29] …’ try to connect better the end of a sentence and the beginning of the following. Results hard to read sometimes and follow a coherent description of the subject.
Line 90. Here again a sentence beginning with a reference. Improve the redaction.
Line 114. In this line is that you define for the first time the Pearl River Basin as ‘PRB’. Why don’t do it before?
Add a reference for the elevation and hydrographic data used in Figure 1.
Line 156. Remove the CRU, it is obtained from the interpolation of local observations.
Line 160. ‘Compared to other reanalysis datasets it has better spatial resolutions of 0.25° x 0.25°’ It doesn't make much sense that you described before the advantage of using precipitation data generated not only from observations, but also from other sources such as satellites, and now they say that they use Aphrodite data, which are interpolated from observations. In addition, there are other datasets with much better resolution than 0.25º. For instance, other precipitation datasets like MSWEP and CHIRPS (this has a shorter available period of data), have much better resolution, and are based on satellite and observational datasets, and more sources. So, your study does not differ much from those that used local precipitation values from different stations, even when the Aphrodite dataset has been worldwide recognized.
Add the original reference for the Mann-Kendall and the Sen´s Slope.
Line 241. Its sound better to say December, January, and February.
In the captions of Figure 5 and 6 add the period of study.
Line 476. Why to discuss at this point the trend of the annual precipitation when it could be done at the beginning and then focus the discussion on the extreme values?
Figure 9. Add ‘trend of annual mean precipitation’
The section 4.3 lacks of a spatial analysis.
Reviewer 3 Report
The article entitled “Spatiotemporal changes in extreme precipitation in China’s Pearl River basin during 1951-2015” is well structured, with good scientific writing and with consistency in the data/indices evaluated. The “Acceptance” of the article is recommended, with minor revisions:
In most of the figures, the identification of the axes and legends are in very small font size. A general suggestion is that they be revised to improve visualization, especially on mobile devices.
INTRODUCTION
- Insert a review on the use of CCI/CCLIVAR (Climate Change Monitoring and Detection Rates) indices linked to precipitation specifically for China. Do quotes from lines 52 to 59 use these indices? If they have not used it, this must be detailed.
- In line [87] identify the abbreviation POT; an acronym that appears for the first time in the text needs to be identified.
MATERIAL AND METHODS
- Correct the points "West of the Watershed" and "North of the Watershed" in Figure 1. They are wrong, regarding the positioning in the Figure.
- Identify XRB, DRB and BRB in Figure 1
RESULTS
- In Figure 2, only SDII was significant at 5%. Displays the R² value (coefficient of determination) for this index;
- In Figure 4, identify which figures correspond to each seasonal period (it is understood that the variations are in the columns); Likewise in Figure 6 (it is understood that the variations are in the lines). It is necessary to present these distinctions clearly for the Figure to be self-explanatory.
