Dear Authors,

The paper has been appreciated by the two referees. However, the main issue raised by the first referee is that the authors should make a further effort to highlight the originality of the work and increase the impact of their study. I think the first referee made valuable suggestions in this regard: i) analyse the impact on results of the method used to extract the channel network from DEM and the calculation of the slope on the topographic index (TI); ii) improve the analysis of the results obtained by comparing TI and CTI (Compound Topographic Index) on a limited number of specific basins to overcome some limitations of the study (different terrain data quality depending on latitude, impact of the grid size on indices, impact of the slope direction method chosen, limitations discussed in section 4.2, etc.).

In general this paper offers an important contribution to modelling land surface water flow using TOPMODEL. The paper will be reconsidered after revisions of these points are being taken and included into the manuscript. Please highlight clearly what you changed in the revised manuscript, so the reviewers are able to assess your changes.

Kind regards,

Roger MOUSSA

Dear Dr. Marthews:

I am pleased to accept "High-resolution global topographic index values for use in large-scale hydrological modelling" for publication in Hydrology and Earth System Sciences.

I thank you for submitting your best work to Hydrology and Earth System Sciences.

Sincerely,

Roger Moussa