Dear Authors,

The paper describes a method to upscale high-resolution data, based on former work (Yamazaki et al., 2009; Wu et al. 2011). As stated by both reviewers, the topic is of high interest for the hydrological community. and the paper represents significant progress for the previous concepts generally used in the literature. However, both reviewers raised some crucial points:
i) The global organization of the paper which need to be improved.
ii) The need to clarify the scientific objectives of the paper which is rather technical : the usefulness and the importance of the method, the added value in comparison to other approaches, and a better justification of the data and methods used.
iii) Citation of previous papers, projects (e.g. ISI-MIP), databases.
iv) Clarification of some points (see the reports).

The Authors gives convincing responses for some points raised by Reviewers, and proposes ways to improve the manuscript.

As suggested by Reviewers, I propose that the paper be reconsidered after Major Revision, asking the authors to prepare a revised version of the paper responding to all points raised by both Reviewers.

Kind regards,

Roger Moussa

Dear Authors,

The revised version takes into account both reviewers' comments. I suggest that the paper be published subject to technical corrections (see Reviewer #1).

Kind regards,

Roger Moussa