Deltas in Arid Environments

Round 1

Reviewer 1 Report

The paper is a comprehensive review of Deltas in arid environments. It depicts an interesting and complete pattern of main threats to the preservation of precious natural environments. The paper is too long and sometimes difficult to follow. Introduction doesn't state the main aims of the paper but it's just a summary. All figures should show geographic coordinates. I suggest the paper could be improved in the form, making it more readable and interesting to the reader. Few typos are marked on the pdf file. 

Comments for author File: Comments.pdf

Author Response

The paper is a comprehensive review of Deltas in arid environments. It depicts an interesting and complete pattern of main threats to the preservation of precious natural environments. The paper is too long and sometimes difficult to follow. Introduction doesn't state the main aims of the paper but it's just a summary. All figures should show geographic coordinates. I suggest the paper could be improved in the form, making it more readable and interesting to the reader. Few typos are marked on the pdf file.

Response: The introduction has been rewritten to state the main aims of the paper.  All figures now have a scale. All typos have been corrected 

Reviewer 2 Report

I went through the paper. It is well written. Just I think it is better to summarize the charactristics of each of these three study areas in a Table. this help readers to understand everything easily.

Author Response

I went through the paper. It is well written. Just I think it is better to summarize the charactristics of each of these three study areas in a Table. this help readers to understand everything easily.

Response: We include a table on the 3 deltas.

Reviewer 3 Report

The paper "Deltas in Arid Environments" by Day et al. presents a huge and quite detailed description of 4 delta systems across the globe (Colorado, Nile, Tigris-Euphrates and Indus), by illustrating their geographic, climatic and gemorphological settings and main socio-environmental issues, often associated to water control by dams.

Despite the huge literature included, the paper is mainly a well-documented summary of knowledge on these selected arid delta environments and not really a systematic review. In particular: (i) a clear indication of purposes/objectives of the work is missing in the introduction; (ii) a state of art knowledge about arid deltas (and need for such a review) is not explained; (iii) a clear justification of the selected case studies is missing too (it is briefly reported in the abstract but not in the introduction); (iv) the structure of the review/paper is not presented as well; (v) the final summary section is almost identical to the introduction, while it should summarise some main lines and key messages from the analysis of the ensemble of case studies (and it should not detail again specific examples from case studies) and some concluding remarks from your huge review work are also expected (e.g. which are the challenges and how to prioritize them?)

In my opinion most of these weakness can be addressed by improving the introduction (1) and summary (6) sections, by addressing the points suggested above. The abstract should also be revised accordingly.

The quality of figures is not always high but these are mostly taken from previous works. Please at least ensure that scale is always indicated for maps.

I’ve also provided few specific comments in the PDF (attached).

Comments for author File: Comments.pdf

Author Response

The paper "Deltas in Arid Environments" by Day et al. presents a huge and quite detailed description of 4 delta systems across the globe (Colorado, Nile, Tigris-Euphrates and Indus), by illustrating their geographic, climatic and gemorphological settings and main socio-environmental issues, often associated to water control by dams.

Despite the huge literature included, the paper is mainly a well-documented summary of knowledge on these selected arid delta environments and not really a systematic review. In particular:

Comment: (i) a clear indication of purposes/objectives of the work is missing in the introduction;

Response: We have revised the introduction to specifically include goals and objectives.

 Comment:(ii) a state of art knowledge about arid deltas (and need for such a review) is not explained;

Response: Arid deltas are the most threatened deltas globally.  To our knowledge, there has not been a review of arid deltas.  Thus, we review four iconic and globally important arid deltas to develop generalizations about the status of arid deltas and what can be done to enhance their sustainability.  We revised the text to make this clear.

Comment: (iii) a clear justification of the selected case studies is missing too (it is briefly reported in the abstract but not in the introduction);

Response: As noted above, the four selected arid deltas are iconic and globally important.  Taken together, the issues discussed about these deltas allow us to draw general conclusions on the status of arid deltas in general.  We revised the text to make this clear.

Comment: (iv) the structure of the review/paper is not presented as well;

Response: We have revised the introduction to clearly state the structure of the paper.

Comment: (v) the final summary section is almost identical to the introduction, while it should summarise some main lines and key messages from the analysis of the ensemble of case studies (and it should not detail again specific examples from case studies) and some concluding remarks from your huge review work are also expected (e.g. which are the challenges and how to prioritize them?)

Response: We revised the final section to address these issues.

Comment:In my opinion most of these weakness can be addressed by improving the introduction (1) and summary (6) sections, by addressing the points suggested above. The abstract should also be revised accordingly.

Response: As noted above, we have revised the text to address these points.

Comment:The quality of figures is not always high but these are mostly taken from previous works. Please at least ensure that scale is always indicated for maps.

Response: Some figures have been improved and a scale has been added on figures where necessary.

Round 2

Reviewer 3 Report

The introduction and the summary sections are improved. Thank you.

Few minor suggestions/edits:

Table 1. Characterization of arid deltas included in this study

Line 314: nutrients

Line 316-317: check date please

Line 753: check "vias" please