|The authors have provided a substantially revised manuscript for review. The revised manuscript, after removal of extraneous narrative and figures, is now somewhat more targeted on tractable research questions and the presentation of a nice high-frequency data set. With the revisions, the authors have made good progress towards addressing the multiple reviewers who were fairly consistent in their critiques of the manuscript. The narrative now more narrowly focuses on how and why in-stream flow and solute patterns vary in three different settings under very different wetness conditions. Despite these improvements, I still feel that major revisions are needed to continue to refine the manuscript for publication. |
In my previous assessment, I had three primary areas of concern. The inclusion of sensor QA information has addressed my first concern and has given me the opportunity to more comprehensively assess the results and discussions. My other two other concerns (i.e., unsubstantiated inference based upon hysteresis analysis and manuscript organization) were partially addressed, but I have lingering concerns regarding both. In addition, I highly encourage further revisions to address writing style, vagueness, redundancies, and transferability of findings. I have made many comments and suggest many edits in the accompanying marked manuscript. Beyond those detailed edits and comments, I offer these general suggestions:
1) Hysteresis analysis: I still struggle with this portion of the manuscript. It is long, rambling, and mired in details. Much of this analysis could be removed without diminishing the study. The results and discussions on this topic need to be properly separated into the appropriate sections of the manuscript. For example, none of the figures are presented in the results. Moreover, I feel that the hysteresis analysis is overemphasized and the interpretation of hysteresis is excruciatingly long. It is still my contention that hysteresis analysis, while moderately useful for general assessments of mixing of waters in streams from various potential end-members, is not a robust approach for the assessment of specific processes without explicit measures that have not been undertaken within this research (or at least presented in this draft of the manuscript). The authors focus on minutiae of complex loops, which have limited intepretability within the context of the overarching goals of the research. Additionally, the hysteresis index is hardly used and could be removed. I think that the nearly four pages of discussion/results on hysteresis loops could be reduced to several discussion points and be presented in one or two short, well-crafted paragraphs about source or transport limitations for the various analytes. I did find inclusion of some nitrate concentration data from soils in the Blackwater catchment to be substantive and informative. And, their discussion of groundwater influence on the chemistry of Wylye basin is nicely supported by the hysteresis analysis. Nonetheless, the entire discussion of hysteresis could be vastly reduced to several key, substantiated findings that directly address their research goals, while avoiding rambling supposition and tangential topics.
2) Organization: While the authors have done a fine job of moving most information to the appropriate sections, the presentation of hysteresis results in the discussion is one area where reorganization is necessary.
3) Writing style and grammar: The authors need to:
* Use the active voice whenever possible. Use direct wording, which along with the use of active voice, will more clearly communicate ideas.
* Scrutinize the entire document for verb tense. Past tense must be used whenever presenting and discussing results.
* Avoid subjective or vague statements and provide specifics whenever possible. See the marked manuscript for many examples. As one specific example, it would be more helpful to have "pressures" (p. 5, line 18) specified. In practical terms, it matters what the pressures are, not that they exist. Or, instead of writing that the data provide insight, describe what that insight is.
* Assure that singular and plural forms are appropriately used such that there is always agreement between subjects and verbs or direct objects or correspondence to the item described.
* Rewrite runon sentences (several examples noted in the marked manuscript).
* Remove personification.
* Remove dangling modifiers.
* Use appropriate verb tenses, the active voice, and more direct language to clearly distinguish between findings and supposition. That is, make it absolutely clear when findings are supported by presented data, that inference is being made from data, or that inference is supported by findings of others.
4) Redundancies and irrelevant information: The manuscript is long. Some topics reappear numerous times and some topics are not well integrated into the manuscript or are simply irrelevant. I have made some suggestions for deletions. The authors need to consider what information is really most relevant to the telling of a concise story and remove topics that are repeated or tangential.
5) This manuscript, with a discussion focused on the DTCs and little comparison to other catchment studies, comes across as a case study with little transferability to other locations or situations. I still find the introduction of the broader DTC study to be excessive and something that could be trimmed. While an important case study, I urge the authors to find ways to explicitly link their points about management to other locations and situations. If they generalize portions of their discussions and conclusions, the work could contribute to a broader science. For example, they devote considerable text to setting up a hydrogeologic framework for the study design, but have not really capitalized upon how that framework may offer particular insights to other locations. I do point out one example in the marked manuscript wherein theirs results are portrayed in a broader context – I highly urge the authors to follow that example when revising. Overall, I encourage the authors to focus on their specific findings that are of general relevance to other researchers, resource managers, and geographic areas. Otherwise, the work is likely to resound with only a small group having an interest in the particular DTC catchments.
6) My previous comment on a more specific title still stands. It would be more informative to potential readers to know about the focus on N and P. The manuscript only describes 2 of the well over 20 nutrient elements.