Effect of Urban Stormwater Road Runoff of Different Land Use Types on an Urban River in Shenzhen, China

Round 1

Reviewer 1 Report

Dear Authors,

the paper is interesting but it needing some improvements before publication. Research on quality of stormwater, especially runoff from urban areas, is necessary. But it is not new subject and many articles in this field have been already published. This study has little interest in the international scale, and very much focused on the specific case study. But the outcomes can be beneficial for the government to develop local strategies.

The paper is well-organized, containing all of the expected components. In my opinion the part “5. Conclusions” could be improved. The applied methodology was effective for attaining the object of this work. The text requires a small editorial correction, for example: equations, description of figures and tables.

Please, format the references according to the journal's guidelines: DOI number should be added.

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 1 Comments

Dear Authors,

The paper is interesting but it needing some improvements before publication. Research on quality of stormwater, especially runoff from urban areas, is necessary. But it is not new subject and many articles in this field have been already published. This study has little interest in the international scale, and very much focused on the specific case study. But the outcomes can be beneficial for the government to develop local strategies.

The paper is well-organized, containing all of the expected components. In my opinion the part “5. Conclusions” could be improved. The applied methodology was effective for attaining the object of this work. The text requires a small editorial correction, for example: equations, description of figures and tables.

Response:

Thanks for these precious suggestions. In this updated version, Conclusion have been improved and revised (line: 360-374). Equations, description of figures and tables have also been modified in the revised manuscript according to the reviewers’ comments. We hope the article could be acceptable for publication in its current version.

Point 1:

Please, format the references according to the journal's guidelines: DOI number should be added.

Response 1:

Thanks for these precious suggestions. We have added DOI number in the references.

Reviewer 2 Report

Please, see the enclosed file.

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 2 Comments

In this manuscript, the authors aimed to determine the variations of pollutants in surface road runoff and the related influencing factors, based on an investigation during five observed rainfall events.

This study is on a topic of relevance and general interest to the readers of Water journal. In my opinion, the manuscript is overall well written and well organized. The description of some critical points is not sufficient or completely missing. There are also some scientific/methodological approaches that need to be correctly presented and some other issues to be revised. In the following paragraph, there are comments meant to help the authors to improve their manuscript.

Response:

Thanks for these precious suggestions. In this updated version, all the errors mentioned by reviewer 2 have been revised. The description of some critical points have been supplemented in the revised manuscript (Figure 5 and Table 7). The description of scientific/methodological approaches have also been improved in the revised manuscript. We hope the article could be acceptable for publication in its current version.

I suggest the publication of the paper after mayor revisions.

Magor comments:

Point 1:

In my opinion, considering that the main aim of this work is finding a relationship among pollutants and their influencing factors, the methodology adopted (multicriteria decision making methods (MCDM)) is not the best one. This is confirmed from the fact that the authors are only using GAIA, which is a visual representation based on PCA, and are not using the ranking that represents the usual output of a PROMETHEE analysis. The authors should adopt a more suitable method to accomplish their objective, i.e. a PCA coupled with K-means cluster analysis. This suggestion is based on the description of FIGURE.5 (lines 229-237), where the authors try to visually identify similar groups of the represented objects. I recommend the following publications where this methodology was already applied:

——Liu,A.; Carroll, S.; Dawes, L.; Goonetilleke, A. Monitoring of a mixed land use catchment for pollutant source characterization. Environ. Monit. Assess. 2017, 189-336.

——Gorgoglione, A.; Gioia, A.; Lacobellis, V. A framework for Assessing Modeling Performance and Effects of Rainfall-Catchment-Drainage Characteristics on Nutrient Urban Runoff in Poorly Gauged Watershed. Sustaninability 2019, 11, 4933.

Response 1:

Thanks for these precious suggestions. We have added the results of ranking to represent the outcomes of a PROMETHEE analysis in Table 7 (lines: 237-241). Moreover, cluster analysis have also been used in the revised manuscript to identify similar groups of the represented objects (Figure 5b) (Lines: 242-248).

Point2: The entire part related to description of input matrix used for the hierarchical cluster analysis is not described. Furthermore, the Authors are not mentioning how they are evaluating the distance in this analysis.

Response 2:

Thanks for these precious suggestions. We added the description of the input matrix used for the hierarchical cluster analysis in the revised manuscript (Lines: 158-162). We also added the evaluation of clustering distance of the HCA analyses in the revised manuscript (Lines: 162-164).

Minor comments:

Point 3: I suggest to revise some acronyms throughout the manuscript and standardize them to the water-quality modeling state of the art. For instance, total suspended solid’s acronym is TSS and not SS; hierarchical cluster-analysis’ acronym is HCA and not just CA.

Response 3:

Thanks for these precious suggestions. Some acronyms in the manuscript have been revised.

Point 4: Line 90: Should “Table 1” be substituted with “Table 2”?

Response 4: Revised.

Point 5: The authors should mention Table 1 in the text.

Response 5:

Thanks for these precious suggestions. We have cited Table 1 in the revised manuscript (lines: 90, 108).

Point 6: In this work, five rainfall events are considered. It is not clear if they are measured at the 10 monitoring stations or just in some of them.

Response 6:

Thanks for these precious suggestions. All of the ten sampling sites from these three types of urban land use were collected from the first rainfall event to identify the effect of land use on runoff pollutants (Table 2). We added the related description in the revised manuscript. According the result of the UPGMA clustering, PS02, PS04, and PS08 were chosen as the representative sites for each land type, and samples from these sites were collected from five rainfall events (include the first rainfall event) to explore the effect of rainfall intensities on pollutant concentrations (lines: 91-97).

Point 7: Paragraph 2.3: It does not exist only one definition to quantify the first flush in an urban area. I suggest the authors to present more definitions and consider the following publications:

——Maciej Mrowiec, Tomasz Kamizela, Mariusz Kowalczyk. Occurrence of first flush phenomenon in drainage system of Czestochowa. Environment Protection Engineering, Vol.35 2009 NO.2.

——Chow MF, Yusop Z, Mohamed M. Quality and first flush analysis of stormwater runoff from a tropical commercial catchment. Water Sci. Technol. 2011; 63(6):1211-6.

——DI Modugno, M.; Gioia, A.; Gorgoglione, A.; Lacobellis, V.; La Forgia, G.; Piccinni, A.F.; Ranieri, E. Build-Up/Wash-Off Monitoring and Assessment for Sustainable Management of First Flush in an Urban Area. Sustainability 2015, 7, 5050-5070.

Response 7:

Thanks for these precious suggestions. The definitions to quantify the first flush in the above references have been supplemented in the revised manuscript (lines: 147-148, Table 5).

Point 8: Reduce Fig.2.

Response 8: We have reduced Figure 2.

Point 9: Lines 181-183: What about PS01?

Response 9:

PS01, PS02, and PS09 comprised the arterial roads, and these sampling sites grouped into the second cluster (Line: 188).

Point 10: Tab.3 and Tab.5: Modify the tables so that numbers and letters do not start a new line.

Response 10: Revised.

Point 11: The conclusions of a research paper have to summarize the contents and purpose of the study: therefore, they have to stand-alone. In this Section, the authors should restate their thesis and summarize their main points of evidence for the reader. I suggest rewriting this section carefully.

Response 11:

Thanks for these precious suggestions. We have revised the Conclusion Section in the revised manuscript. In this section, we restated the thesis and summarized the main points of our study (Lines: 360-374).

Round 2

Reviewer 2 Report

I am glad that the Authors followed my recommendations and improved their manuscript.

I believe that some typos and a few grammar/style editing are still required; e.g.:

line 45: delete "suspended solids"; lines 91-92 of the revised version: what does it mean "All of the ten sampling sites from these three land use types were collected..."?; furthermore: "all of the ten sampling sites" should be substituted with "the ten sampling sites"; and "land use types" should be substituted with "land-use types"; in the captions of Tab.1 and Tab.2 delete the article; etc.

After a thorough review, I suggest the publication of the manuscript. 

Author Response

I am glad that the Authors followed my recommendations and improved their manuscript.

I believe that some typos and a few grammar/style editing are still required; e.g.:

Response:

Thanks for these precious suggestions. In this updated version, all the errors mentioned by reviewer 2 have been revised.

Point 1:

line 45: delete "suspended solids";

Response 1:

We have deleted “suspended solids” in the revised manuscript (line: 45).

Point2: lines 91-92: of the revised version: what does it mean "All of the ten sampling sites from these three land use types were collected..."?; furthermore: "all of the ten sampling sites" should be substituted with "the ten sampling sites"; and "land use types" should be substituted with "land-use types";

Response 2:

The errors have been revised in the revised manuscript (line: 92-93).

Point 3: In the captions of Tab.1 and Tab.2 delete the article; etc.

Response 3: Revised.

After a thorough review, I suggest the publication of the manuscript.