The authors have clearly put a lot of effort into the revision and this version is substantially improved. This is a useful, well presented paper with a nicely balanced discussion of its limitations and its contributions.
The authors did a nice job of incorporating a brief outline of their approach in the Abstract and Introduction, as requested, and of responding to the other comments on the previous version.
Specific (minor) comments:
1. "Drained peatlands are one of the main sources of carbon dioxide (CO2) emissions globally."
- Could this statement in the abstract be supported with a reference in the text, perhaps by adding a clause to the sentence, "However, drainage may turn peatlands into C sources..." (lines 19-20)?
2. Lines 11-12: "Our solution consistently improved the performance of traditional block locating methods"
- Consider "Our solution consistently outperformed manual block locating methods..."
3. Line 41: "[T]he number of blocks becomes easily limited by available resources"
- "Available resources" is slightly confusing here because the paragraph begins by discussing the material used for blocking. I had the image of running out of peat for the blocks. Change perhaps to "available financial resources", or just "cost"?
4. Line 42: "requiring big constructions"
-> "requiring large structures"
5. Line 43: "amount"
-> "number" of blocks.
6. Line 84: "and the peat depth defines the impermeable bottom ib"
- Perhaps "the peat thickness defines the depth ib of the impermeable bottom below the peat surface"? I found myself wondering, at this point in the text, what exactly ib was (the elevation of the bottom? Is it a scalar or a field?)
7. Line 88: "[The peat hydrologic model] solves the WTD for the whole area, a quantity that is closely related to the target variable... <zeta>":
- Consider rearranging to: "... solves for WTD in the whole area. WTD is closely related to the target variable... "
8. Line 90: "This onsets a new iteration."
-> "This starts a new iteration."
9. Fig 3: Blue text is much smaller than the text in boxes, and thus a little hard to read. Blue text could be made bigger, or the text in boxes smaller.
10. Line 108: "instead of using the block height as a variable we use its complementary, the block head level hl."
- Delete "its complementary,"
11. Lines 126-127: "The numerical scheme was fully implicit in time for h, and explicit for T (h) and S y (h)."
- The response to reviewers says: "The solution of Eq.(2) was fully implicit in time –both for h, and for T(h) and Sy(h)." Which was it?
12. Line 131: T(h) = ...
- At this point I wonder what exactly ib is (forgetting whatever I learned from previously reading the manuscript). I think to myself: In the equation, I am integrating from ib to h, so I guess z is defined relative to the peat surface, and ib is the depth of the impermeable bottom below the surface? Is ib a scalar or a field? In line 133, I read "ib has a known, fixed value for all the domain", which makes me think it is a scalar. Some minor editing here could make this easier to understand.
13. Line 191: "Therefore, this problem is better tractable with non-linear, global optimization algorithms."
- Consider changing "tractable" to "addressed"
14. Line 193: "Even global optimization algorithms are not guaranteed to find the optimal solution in a convex search space..."
- Delete "convex" (the same is certainly true of a non-convex search space).
15. Line 201: "In SA this is achieved by allowing disimprovements with certain probability."
- Consider: "... this is achieved by allowing steps that worsen the objective function with certain probability."
16. Line 219: "would need"
17. Line 227, explanation of criteria for manual block placement:
- This is great; clear, and fully resolves my comment.
18. Fig 5 caption "a straight horizontal line indicating the cross-section area"
-> "... indicating the location of the cross-section shown in (b)."
19. Fig 5 caption: "amplified"
20. Fig 6 caption: "... their effectiveness varies from each case depending on the local topography..."
- Delete "from each case"
21. Fig 7:
- Figure looks much better; great.
22. Lines 332, 463, and 468: "causal contact"
- Change to phrasing using "upstream" and "contiguous" for consistency.
23. Line 336: "... in reality w is not constant but it might vary in time due to seasonality"
- Define with a phrase, so your reader doesn't have to consult Table 1; something like: "... in reality the initial water table depth w..."
24. Line 364: "As the number of blocks to locate, b, increases, the size of the search space does so as [n choose b]. It is this exponential increase in computational complexity..."
- I suggest deleting "exponential"; the size of n choose b has a maximum near b = n / 2, so it might be better if the reader doesn't think about it too much. Otherwise, perhaps something like "rapid increase in complexity for reasonable numbers of blocks..." or something like that.
25. Page 19: There is some repetition here; could text be condensed?
26. Line 396: "In tropical climates... rainfall intensity is all but uniform in time."
- Try a different phrasing here; the "all but" English idiom has a meaning that is the opposite of what is intended here (https://english.stackexchange.com/questions/9967/all-but-idiom-has-two-meanings) Perhaps: "In tropical climates... rainfall intensity is highly variable in time". The phrase "... rainfall intensity is anything but uniform in time" has the desired meaning but is colloquial.
27. Line 415: "To get a grasp of the magnitude of these numbers, they are of the order of what 25000 cars with an annual mileage of 20000 kilometres would emit."
- This is great. Is there a reference (possibly a website on fuel emissions) that could be cited here?
28. Line 416: Brief section regarding methane
29. Line 434: "Regarding the formulation of the optimization problem, block cost could be introduced by changing the constraint equation"
- Could briefly mention here, if you want, that a convenience of "black box" optimizers like SA and GA is that it is trivial to accommodate a more complex objective function.