The analysis indeed begins to be very interesting! I have a couple of remarks or comments:
– regarding the boxplots used to analyze correlations relative to physical and quantified metrics (such as basin area in Fig. 6), do we really need boxplots? I’m wondering if the boxplots are not aggregating too much information and so hiding some results, maybe scatter plots would provide more information (or did you try and see that they were unusable?). And if using boxplots, the identification of trends or patterns can become subjective: have you thought about using objective criteria for this (significance tests for example).
– effect of elevation: this is one of the simplest geophysical characteristics to get, so I think we should have it for every basin. Also, representing the correlations on a map can be misleading: you plot correlations at the outlets, but sometimes it is not clear if the points are on a tributary or on the main river, and for me the mean elevation is more interesting than the outlet altitude. (but I recognize that we already see some nice information on Fig. 13!).
– We can provide for France mean values of P and T if needed.
The basis of the article is already good, thanks!