Participatory Geographic-Information-System-Based Citizen Science: Highland Trails Contamination due to Mountaineering Tourism in the Dolomites
Round 1
Reviewer 1 Report
The article entitled "Participatory GIS-based citizen science: highland trails contamination due to mountaineering tourism in the Dolomites" is an interesting one. The authors are tried to write article with proper findings and explanation. However, the following points are needed to address for publication of this article:
1. In some places the authors need to provide proper explanation which has been identified in the article. Mountain pollution is related with the number of tourists visit in any area. But the authors identified that Dolomites is a tourists hot spot, although how many visitors visit that area is completely absent. These need to address.
2. There exists information gap while writing Materials and methods. The authors identified three areas to conduct this study. But why these three specific areas were selected? Proper explanation is needed here.
3. Figure 1 is not clear enough to understand properly. Moreover, different waste items were grouped during this research. How could the human defecation and urination items were grouped? How these were considered during this study??
4. The distribution, analysis and measurement technique of these waste materials was not standard enough and proper. Hence, a clear measurement technique should be incorporated.
5. All the figures in the Results & Discussion chapter are opaque and unclear. All these must be changed.
6. The Conclusion chapter must be re-written. The conclusions should be based on the findings of this current research.
Comments for author File: 
Comments.pdf
The quality of the article is good.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
The paper title was very promising. Certainly, the topic is important and has scientific potential. Nevertheless, I am not convinced that the current version of the text is suitable for publication in such a reputable journal as Sustainability. Detailed notes:
Introduction: it is some background for the undertaken inquiries. The aim was defined as assess the extent and impact of littering at a target destination for mass tourism of mountaineering and to detect any patterns and characteristics to identify potential strategies or contrasts. In the last paragraph there is a reference to the results obtained. I think that the results can be referred to in the abstract, the introduction should justify the importance of the research and its purposefulness, therefore I suggest omitting this part of the text. Research questions or hypotheses would be useful instead.
Material and methods: no justification for the choice of specific trails, no information about the length of the routes, the planned time of passage, width, etc. There are no basic parameters describing the trail. No justification for measurements up to 2 km from the route. In this regard, it was necessary to rely on at least a few literature items, which clearly show the extent of the impact of tourism on the environment along tourist trails. No statistical methods
Results: I don't think the Authors' findings were particularly revealing. It is understandable that where there is a stop of tourists, a stop combined with rest and at nodal points, the concentration of litter is higher. The Authors discuss each of the trails in the same way, but there is no connection between these considerations. Capturing statistical relationships would have greater scientific value. I think the way of presenting the results in a graphical form is a good idea, thanks to this solution it is easy to see where the accumulation of clutter occurs. It should be noted, however, that the aim was only partially achieved. Indeed, the Authors managed to determine the patterns of littering, but they lack the definition of the extent and impact of littering in mass tourism destinations.
Discusion: The discussion does not include a comparison of the obtained results with the work of other studies
Conclusions - this chapter is rather a summary, conclusions are not clearly formulated and presented in the form of points
Literature - The bibliography is quite modest compared to other papers published in Sustainability
In conclusion, I believe that the text I am reviewing should be thoroughly modified and only then resubmitted to the journal
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors revised the article as per the comments of the reviewer. I think the manuscript is okay for publication.
Reviewer 2 Report
Thank you for considering my comments and preparing answers to the questions I raised. The text is now much better and I can recommend it for printing
