Long-Time-Series Evolution and Ecological Effects of Coastline Length in Coastal Zone: A Case Study of the Circum-Bohai Coastal Zone, China

Round 1

Reviewer 1 Report

The problem discussed in the paper is both important and interesting. The authors collect a lot of data and it gives the opportunity to develop interesting contribution. The quality of the English seems to be good. Nevertheless, English is not a native language of the reviewer, so it is impossibe to give realy valueable linguistic opinion. 

Quality of presentation is judged as low because the figures (being the most important part of data and results presentation) are illegible due to too small font size and relatively poor quality of images - electronic zoom is useless. Consequently, it is impossible to analyse the coastline evolution described in the paper.  This should be changed. In addition the images are not deeply and clearly commented in the text.

For example fig. 6b and the figure caption suggest overall periodic loss and restoration, whereas the comments in the text say something different. This is only one example of the lack of consistency in the work.

Many parameters, for example coastline function index or water quaity rating, are not defined. Possibly these (and other) parameters are clear for a narrow group of specialists, but the paper describes a problem which is really important and can attract people from various areas of interest. Therefore some introductory definitions are welcomed.

The authors suggest that some ecological and enviromental effects are caused by coastline changes, but they do not give strong arguments. Comparing various parameters can detect correlation with high relevance but it does not prove the exitence of physical dependency. It would be interesting to get any proposal of an even simplified model of the processes investigated. The data analysed could verify such a model and, consequently, suggest some tools to minimize negative ecological effects.

The lack of such generalised remarks is clearly visible in conclusions. In fact, conclusions constitute summary of result analysis instead of giving the essence of a new knowledge obtained during the work presented.

To summarize, a lot of valueable work and material is presented, but mainly the low quality of images destroyed the effect. In addition it seems that  more general conclusions supported by the data analysed would be better for a wider audience.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper describes and quantifies the evolution characteristics of the coastline in the past 30 years and measured the possible environmental pollution and ecological degradation by spatial and temporal coupling analysis. The text is well structured, many references were cited to give to the reader a complete overview on the methodological approach used. Results are presented in a concise form and data and graphics are readable.  

 

Some specific comments are:

Lines 154-157: please provide some details on sample point data selection criteria and water quality data linking. 

 

In the methodology section a Long-time series coastal zone land-use function classification was presented, how did you select this land-use function, is it the suitable one in function of the land cover classes? What are the benefits in terms of outputs?

 

Water bodies’ classification: please revise and check the reference (line 192).

 

 

Analysis of changes in coastline functions: this seems to be a critical step in your analysis to directly characterize the coastline function. 

 

Evaluation of Ecological and environmental effects caused by coastline changes: you considered water quality and land use change connection to quantify ecological and environmental effects, I suggest to describe in general the environmental effects on coastal ecosystems, because ecological “processes” are affected by more complicated dynamics to be depicted only by five-levels water quality classification. 

 

Figure 6: please explain and clarify in the text what is “Loss of seawater ecological land”. 

 

 

 

 

 

 

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors accepted all the critical remarks and significantly improved both the illustrative material and text. The introduced improvements are satisfactory.

The reviewer has no sufficient knowldge to judge the originality novelty of this contribution, but it seems to be rather high. Similarly, the English seems to be of good quality but it should be checked by native speaker.