General comments

This is a very interesting paper in a much needed area.  The paper proposes a methodology to evaluate inland flood losses for specific events, which potentially could be used for flood disaster management and prevention.

Specific comments

In the conclusion, the authors state that “The estimated 280 spatial distributions of the loss ratio and loss value of the flood disaster accurately reflect the spatial pattern of disaster loss and provide scientific guidance for disaster prevention, mitigation, and emergency rescue”.  This is certainly true, but the paper would benefit form a more detailed explanation on how the work could actually be used for guidance.  May be a whole section on this topic would be welcome.

Also, the procedure for the derivation of the vulnerability curves is not clear, and should be improved and consolidated.

Technical and editorial comments

Overall, the paper would benefit if the authors would try to reduce the use of the passive voice.

Line 16: “values of disaster-bearing bodies.”  Not sure what is meant.  I suggest you use another expression.

Line 29: not sure what a “sponge” city is.

Line 40: I suggest using more recent references for the USA.

Line 54:  I suggest that you add as a reference,

J.-P. Pinelli, Josemar Da Cruz, K. Gurley, A. Paleo-Torres, M. Baradaranshoraka, S. Cocke & D.-W. Shin, ” Data management for the development, validation, calibration, and operation of a hurricane vulnerability model,” International Journal of Disaster Risk Science, November 2020, DOI 10.1007/s13753-020-00316-4

Line 76: is this correct: the district is in the city?  Or should it be the reverse?

Line139:  Not if the expression remote sensing is the correct one.  Remote sensing refers to the acquisition of data through sensors at a distance, hence remote.  From your description this is not the case. It seems you are describing process of digitization.

Line 146:  Not sure what is meant by “traversed”.  Please, clarify.

Line 170:  you might want to reference and look into different reports from the US Corps of Engineers.  I believe that HAZUS inland flood curves are actually derived from their work.

Section 3.3 and line 221: If I understand correctly, you have data of accumulated loss as a function of land use.  For each type of land use, you adjust the parameters of the equation of your vulnerability curve till you get the optimum fit (least error between model and data).  In number 4) you mention the “scale parameters”, but I am not clear what they are.  Could you please clarify?

Now I see your figure 6, but you have a reference there to FEAM 2013, which I cannot find in your list of references.  Also, in the figure caption you write that the color curve is the optimized result, but the graphs seem to indicate the reverse, with the black being the best fit to the data.  Am I missing something?  Am I correct in interpreting that the black dots in your figures are data points from the references, to which you initially fit you VC, and then you adjust some kind of scale parameter to get a new optimized fit to your own data for the Liandu event?  This is somewhat confusing and need to be better explained and clarified.

Line 262:  fortification should be replaced by mitigation.  If you are not referring to mitigation, then, please clarify the meaning.

Line 269: “more reasonable” than what?  The last sentence of that paragraph should be rewritten to clarify the meaning.

Line 286:  I don’t know what sponge city planning means.

General comments

The paper aims to build a refined assessment model of direct economic losses for flood disasters. Taking the “8.20” flood event hitting Linshui City in 2014 as an example, the loss ratio and loss value of this disaster event was calculated based on the land use data. The topic is interesting, and the paper is well structured. I would recommend following suggestions to improve the manuscript:

Specific comments

1. Line 14: please clarify what is the “flooding model”.
2. Line 16-17: “Then, the existing vulnerability curve database was summarized, and the curves were calibrated by disaster loss reporting.” This sentence does not make it clear the process of constructing and checking the vulnerability function. I suggest that you rewrite this sentence.
3. Line 19: “high-precision spatial information” should be replaced by “high spatial resolution”.
4. Line 70: there is no legend in the light blue area in Figure 1 (b).
5. Section 2.3: howto verify the results of flood inundation simulation? How accurate is the simulation of flooding? There is no detailed description of these in this paper, please give a brief description.
6. Line 140: it is recommended that you quote Table 2 in “47 categories” to indicate the specific classification.
7. Line 141: you have a reference for GB 50137-2011 here, but it is not in your reference list. Please add it.
8. Section 3.3: the steps for fitting and optimizing the vulnerability function of land use are not clear, and it is recommended to describe them in detail.
9. Line 173-174: please indicate which data source each type of land use refers to. You can quote the Figure 6.
10. Line 186: “Based on the mapping relationships between the disaster statistical indicators and land use types”. There are 41 statistical indicators for disaster loss reporting in Section 2.4. It is suggested to add this mapping table to determine which indicators are used in this study.
11. Line 189: please clarify what is the “scale parameter” .
12. Line 193: “corresponding” should be replaced by “respective”.
13. Line 231: it is recommended to specify what the black dots in the Figure 6 refer to. In addition, Figure 6(42) should add the index and titleof the horizontal axis.
14. Line 240: please clarify what is the “spatial analyst algorithm”.