Quantitative Characteristics of the Current Multi-Source Precipitation Products over Zhejiang Province, in Summer, 2019

Round 1

Reviewer 1 Report

The manuscript has a great potential to be published after some minor revisions:

• Discuss the main reasons for the variations of the POD, FAR and CSI for five precipitation products over Zhejiang province.
• The paper should be improved by citing more literatures. I have listed some useful papers for this matter:

Assessing Future Changes of Climate Extreme Events in the CORDEX-MENA Region Using Regional Climate Model ALADIN-Climate | SpringerLink

Impact of Different Cumulus Parameterization Schemes in SAUDI-KAU AGCM | SpringerLink

Performance of Land Surface Schemes in the WRF Model for Climate Simulations over the MENA-CORDEX Domain | SpringerLink

Using Drought Indices to Model the Statistical Relationships Between Meteorological and Agricultural Drought in Raya and Its Environs, Northern Ethiopia | SpringerLink

Evaluation of TRMM 3B42V7 and CHIRPS Satellite Precipitation Products as an Input for Hydrological Model over Eastern Nile Basin | SpringerLink

• How can extend the results in other regions with similar/different climates?
• At the end of the manuscript, explain the implications and future works considering the outputs of the current study.
• The quality of the language needs to improve by a native English speaker for grammatically style and word use.

Author Response

Reviewer #1 (Comments to Author):

The manuscript has a great potential to be published after some minor revisions:

Response: We are truly grateful to you for the critical comments and thoughtful suggestions regarding our article ("Quantitative characteristics of the current multi-source precipitation products over Zhejiang province, in Summer, 2019 ", #water-1054806). Though minor revision is needed, we have taken great attentions on revising the manuscript, for example, we have rewritten the sections including Abstract, Introduction, Study area and Materials, Methods, and Conclusion. Additionally, we have added a new Discussion section to make a more comprehensive improvement on the quality of this manuscript. Meanwhile, all the authors pay great attention on the English grammar and expressions this time.

Point 1. Discuss the main reasons for the variations of the POD, FAR and CSI for five precipitation products over Zhejiang province.

Response: It is a very good suggestion, which improves the robust of this manuscript. And we have added the potential reasons in lines, from 394 to 401, in the revised manuscript, shown as follows: “The reason of ERA5-Land with the largest POD values, is probably that ERA5-Land is a comprehensive reanalysis precipitation product fusing large amounts of observations from multi-sources and multi-sensors from various platforms.  As for the main reasons for the variations of the POD, FAR and CSI for five precipitation products over Zhejiang province, the inversion algorithms, observation sources, calibration procedures, orographic characteristics, and precipitation distributions might be the main factors”.

Point 2.  The paper should be improved by citing more literatures. I have listed some useful papers for this matter:

(1) Assessing Future Changes of Climate Extreme Events in the CORDEX-MENA Region Using Regional Climate Model ALADIN-Climate | SpringerLink

(2) Impact of Different Cumulus Parameterization Schemes in SAUDI-KAU AGCM | SpringerLink

(3) Performance of Land Surface Schemes in the WRF Model for Climate Simulations over the MENA-CORDEX Domain | SpringerLink

(4) Using Drought Indices to Model the Statistical Relationships Between Meteorological and Agricultural Drought in Raya and Its Environs, Northern Ethiopia | SpringerLink

(5) Evaluation of TRMM 3B42V7 and CHIRPS Satellite Precipitation Products as an Input for Hydrological Model over Eastern Nile Basin | SpringerLink

Response: Thank you very much for providing these valuable references for improving the manuscript, and we have cited all these recommended literatures in the Introduction, in lines from 64 to 70. Additionally, we have also added several other related references in the Introduction, which are clearly demonstrated in the Reference.

Point 3. How can extend the results in other regions with similar/different climates?

Response: Although we have conducted the evaluations on the five precipitation datasets in Zhejiang province, while as for the other regions, the findings of this study could provide preliminary references for related applications, while the similarities and differences of the performances of precipitation products in other regions could be furtherly exploited, we have added the information in the manuscript in lines from 510 to 512.

Point 4. At the end of the manuscript, explain the implications and future works considering the outputs of the current study.

Response: A great good suggestion! We pointed out that “In the future research, two aspects should be focused on great attentions: (1) in terms of evaluations, much more detailed error characteristics could be revealed by applying these gridded precipitation products in the spatial distributed hydrological models; and (2) more wise inversion algorithms for generating FY4A QPE should be developed by integrating the satellite-based radar observations, which is not considered at current stage”, which have been added at the end of this manuscript in lines from 512 to 516.

Point 5. The quality of the language needs to improve by a native English speaker for grammatically style and word use.

Response: Thank you very much for pointing out the language issues. All the authors have paid great attention on the English grammar and expressions this time, and we have almost rewritten this manuscript compared with those of previous version, especially in sections of Abstract, Introduction, Study area and Materials, Methods, and Conclusion.

Author Response File: Author Response.pdf

Reviewer 2 Report

Please, find my comments in the attached pdf.

Comments for author File: Comments.pdf

Author Response

Reviewer #2 (Comments to Author):

General Comments:

The paper focuses on the analysis of the performance of four different hourly/subhourly satellite-based rainfall products compared to the China Merged Precipitation Analysis spatio-temporal dataset (which is considered as the reference dataset). The analysis has been performed in Zhejiang province (China) during the period of summer of 2019. The authors used different performance metrics for their results. Finally, after showing and discussing the results, the authors conclude that the most suitable precipitation product for Zhejiang province is GSMap_Gauge (reference dataset), followed up by IMERG-Final, ERA5-Land, PERSIANN-CCS and FY4A QPE. This manuscript has a potential interest for Water journal readers. The paper is written satisfactory, so potential readers will understand the research. However, I have some major concerns about the research:

Response: We are truly grateful to you for the critical comments and thoughtful suggestions regarding our article ("Quantitative characteristics of the current multi-source precipitation products over Zhejiang province, in Summer, 2019 ", #water-1054806). Though minor revision is needed, we have taken great attentions on revising the manuscript, for example, we have rewritten the sections including Abstract, Introduction, Study area and Materials, Methods, and Conclusion. Additionally, we have added a new Discussion section to make a more comprehensive improvement on the quality of this manuscript. Meanwhile, all the authors pay great attention on the English grammar and expressions this time.

Point 1. The authors ranked the different satellite-based rainfall products for Zhejiang province basing their conclusions only in the performance of the products during the summer of 2019. I believe that drawing up these conclusions from studying a three-months period of one year is an important limitation of the research that should be clearly stated within the manuscript.

Response: A very good suggestion!  This time we have added a new sub-section in Discussion to support the findings of this manuscript in lines from 430 to 458, shown as follows:

5.3 Overall comparisions on the performances of the fivew precipitation products in summer 2018 and 2019

This study also assesses the performances of the five precipitation products in summer, from June to August 2018, to check their stabilities (Figure 7). Overall, the relative performances of the five precipitation products in summer, 2018, are overall consistent with those in summer, 2019. Especially in terms of occurrence detections (POD, FAR, and CSI), the relative performance of all the five products in summer 2018 is similar to those in summer, 2019. For instance, in terms of POD, GSMap_Gauge and IMERG-Final also performs better than the others in summer, 2018, with mean values of around 0.60 and 0.59, respectively, and the PERSIANN-CCS still performs worst with mean value of POD is around 0.28. Simliarly, in terms of FAR, ERA5-Land performs worst with the largest mean value of FAR (around 0.65) than the others, in Summer, 2018. Therefore, the evaluations on the five precipitation products provide valuable references for demonstrating the quantative characteristics, conducted in summer, from June to August 2019.

Figure 7. Boxplots demonstrate the relative performances of CC, bias, RMSE, POD, FAR and CSI of the five precipitation products in summer, from June to August 2018, and 2019, respectively.

Point 2. Therefore, I suggest the authors to perform the same analysis in different periods and years, to verify the conclusions are consistent and reliable.

Response: A very good suggestion!  This time we have added a new sub-section, conducted in the year 2018, in Discussion to support the findings of this manuscript in lines from 430 to 458, which have been clearly responded above-mentioned. 

Point 3. Furthermore, I miss more explanations on the limitations of the reference dataset. The results can be biased due to limitations of the CSMap_Gauge product. Therefore, in my opinion, the aforementioned major comments should be addressed by the authors. Even though the paper is well structured, the authors should try to extend the research to other periods to verify the consistence of their conclusions, before the manuscript is ready to be published. Furthermore, I have some specific comments and suggestions in the following section.

Response: We have carefully revised the manuscript based your constructive comments, which have been addressed by the authors, shown as above-mentioned. Thank you very much again.

Specific comments:

Point 1. As a general comment, I suggest adding a subsection within section 2 explaining which the limitations of the analysis are carried out.

Response:  It is really a good general comment for pointing out that drawing up these conclusions from studying a three-months period of one year is an important limitation of the research. According to your suggestion, we have added a new sub-section in the Discussion to support the findings of this manuscript in lines from 430 to 458, shown as follows:

5.3 Overall comparisions on the performances of the fivew precipitation products in summer 2018 and 2019

This study also assesses the performances of the five precipitation products in summer, from June to August 2018, to check their stabilities (Figure 7). Overall, the relative performances of the five precipitation products in summer, 2018, are overall consistent with those in summer, 2019. Especially in terms of occurrence detections (POD, FAR, and CSI), the relative performance of all the five products in summer 2018 is similar to those in summer, 2019. For instance, in terms of POD, GSMap_Gauge and IMERG-Final also performs better than the others in summer, 2018, with mean values of around 0.60 and 0.59, respectively, and the PERSIANN-CCS still performs worst with mean value of POD is around 0.28. Simliarly, in terms of FAR, ERA5-Land performs worst with the largest mean value of FAR (around 0.65) than the others, in Summer, 2018. Therefore, the evaluations on the five precipitation products provide valuable references for demonstrating the quantative characteristics, conducted in summer, from June to August 2019.

Figure 7. Boxplots demonstrate the relative performances of CC, bias, RMSE, POD, FAR and CSI of the five precipitation products in summer, from June to August 2018, and 2019, respectively.

Point 2. L26: Please, indicate the exact period of the case study (months) when stating “summer, 2019”.

Response: A very good suggestion, we have stated the summer, 2019, almost everywhere it appears, for example, in lines 27, 96, 270, 325, etc.

Point 3. L194: Please, when stating: “the PERSIANN-CCS obviously underestimates precipitation in the whole province with a small amount” why is it so obvious? Does PERSIANN-CCS underestimate precipitation in other case studies in literature?

Response: Yes, it is not a clear description. We have rewritten this part in lines from 274 to 275, shown as follows: “Compared with the CMPA, the PERSIANN-CCS underestimates precipitation with volumes smaller than 800mm (Figure 2b)”.

Point 4. L320: Instead of “will be our important work in the future” I suggest saying “will be our further research work” or something similar, avoiding subjective wording (“important”). This is a general recommendation for reviewing this kind of wording within the whole manuscript.

Response: Very good suggestion, we have carefully revised all the expressions throughout the manuscript. And for this part, we have rewritten it, in lines from 420 to 421, shown as follows: “Therefore, how to decrease of the proportion of false alarms will be one of the further research work”.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have addressed all the comments. Therefore, I consider the paper is ready to be accepted for publication.

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

I appreciate the Editor to give me a chance to review an interesting and valuable paper. I found some merits in the both methodology and results. In my opinion, this paper has a good potential to be published in the journal. However, I have also some concerns on the different parts of the manuscript. If the author(s) address carefully to the comments, I’ll recommend publication of the manuscript in the journal:

• Why didn’t you use ERA-5 instead of ERA-5-Land?
• In the Tables, highlight values that are more important and discuss them for better understanding readers.
• The Results and Discussion section should be broken to sub-sections for better understanding readers.
• Discuss the main reasons for the variations of the spatial patterns in terms of bias based on PERSIANN-CCS, ERA5-Land, FY4A QPE, GSMap_Gauge, and IMERG-Final against CMPA at hourly scale over Zhejiang province in summer, 2019.
• What are the strategies/recommendations to reduce uncertainties in this study?
• How can extend the results in other regions with similar/different climates?
• The quality of the language needs to improve by a native English speaker for grammatically style and word use.

Reviewer 2 Report

I have attached my comments for the paper 

Comments for author File: Comments.pdf