The authors have used gridded rainfall data (TRMM) and employed them in a hydrological (HEC-HMS) and hydraulic model (HEC-RAS) to simulate flood events in Pakistan. There are numerous studies like this in literature and therefore I do not get the importance of this study based on the introduction presented in this paper. I request the authors to revise based on the comments and re-write the introduction with a better problem statement and providing the importance of this study.

1. How is the site inaccessible (as mentioned in the title of the paper) where the authors have acquired secondary data of river discharge from organisations?
2. The abstract is too big. There are many sentences which are not required such as line 16-18. An abstract should have a simple problem statement which the work plans to solve followed by the body with objectives and approaches applied. This should follow with results and wider application of the study in conclusion (the conclusive statement of this paper is good).
3. Ln 23: Please replace “collected and use” with “used”. Also, what is driver discharge here?
4. Ln 57-63: These lines don’t fit here. They should be shifted to the methods part as they mention the approaches and methods used in this study.
5. Ln 69-70: Please do not put sentences like this “in this study…….” In the introduction as they are more suited to the methods. The introduction should set up the problem and what the study is aimed to solve.
6. Ln 71-76: Too many details about TRMM gave. No need of all these as this paper is about the application TRMM then the focus should be why TRMM is more suitable and important compared to other sources such as APHRODITE or CRU. BY the way why was TRMM data chosen for this study?
7. Similarly, in the paragraph about HEC models, the authors should focus on what HEC provides that other models do not give and is suitable for this particular study. I am sorry about the introduction contents do not set up the problem appropriately.
8. Ln 90 Please cite Deb et al. (2018) hereafter “hydrographs”. Deb, P., Babel, M. S., & Denis, A. F. (2018). Multi-GCMs approach for assessing climate change impact on water resources in Thailand. Modeling Earth Systems and Environment, 4(2), 825-839.
9. Ln 99: Please write the objectives of this study here at the end.
10. Figure 1. Please highlight the catchment within Pakistan for easy understanding of the location within the country. Also please remove the right bottom corner plot.
11. Ln 115: Please check for spacing between “46” and “m3/s” and “1964” and “[36, 37]”. There are similar numerous errors of spacing throughout the paper such as Ln 132 and many many more……. Please check!
12. Ln 136: Replace “observation” with “observed”
13. Ln 145: Is it “pre” processed or “post” processed?
14. Ln 151: Not watersheds.. it should be sub-basins.
15. Throughout the paper please replace “rainfall-runoff” with “runoff” as the work is done in this paper focusses on runoff simulation and not rainfall simulation.
16. Ln 170-172: What are terrain areas? Also please explain geometrical data. Where did the authors get the flood inundation maps?
17. Figure 6: Please convert the peak discharge unit into SI system units.
18. Table 1: Where are the calibrated CN values?
19. Is Figure 8 for the observed or simulated flood?
20. Figure 12: Please be consistent with the texts used in the figures.
21. Please convert “hectares” to “km2” in Table 2.
22. Why the texts in Table 3 are in italics?