Thanks for providing this manuscript on a relevant topic.
As correctly stated somewhere toward the end of the discussion: the numbers are surrounded by large uncertainties. Nevertheless, I find from the abstract until the conclusion EUR values up to the single unit. I suggest replacing them by kEUR to focus more on the order of magnitude of the results instead of the exact values.
Abbreviate corporate author names when used in references. For some of them it is done correctly (e.g. EEA in line 20), other like VMM are sometimes used, sometimes not and for example Agentschap Informatie Vlaanderen, Nationaal Geografisch Instituut, Agentschap Innoveren en Ondernemen are not. The full names, especially when in combinations break the reading flow and therefore the good understanding of these sentences.
Cartography can be improved for almost all figures. Select a line to delineate the catchment and then have a whit background as a starting point. In addition, select different colours and legend classes to improve the readability and relevance of the maps included (More detailed comments below for individual maps).
Important information is the level of detail of the land use maps: these have pixels of 50*50m² resulting in 100 pixels of the DEM having the same land use class. That’s an additional source of uncertainty in the results not mentioned.
The paper referred to (Gabriels et al. 2022) is not yet available to understand some work. However, after enlarging the maps on screen, it looks as the selection of the 750 pixels is based on the RR-model CN parameters only and does not take into account aspects like connectivity to already existing forest plots or to each other. Same for the sealed areas that can occur in the middle of agricultural land and are not necessarily connected to existing urban areas. Is this assumption correct? Although it will probably be expressed in the other paper, some additional details would be welcome to understand what is done here.
Observation – no conclusion: One third of your references (including several websites) is from the last 5 years (2016 or later), and one third is older than a decade (2010 or before). There is a low number of self-references in the paper.
More detailed remarks:
lines 19-20: There’s an indicator for 1980-2019 as well, the EEA reference you give is over a decade old (https://www.eea.europa.eu/ims/economic-losses-from-climate-related). Europe is defined here as EEA member countries or EU-27 (eventually plus UK).
lines 55-57: in particular for agricultural damages, the historic damages were compared with LATIS results. A limited comparison with damage records in the (at the time federal) Rampenfonds were done as well in addition to using NL and UK enquiries.
lines 83-84: in a newly added sentence you describe the work as similar to LATIS, while in the discussion a lot of differences are mentioned. I suggest to remove the newly added sentence.
line 87: the four events are nowhere defined above and only become clear when looking at Figure 4 several pages later.
lines 156-157: while not applied in the study for VMM in 2006, LATIS can also distinguish maximum damage estimates for Flemish ‘landbouwstreken’. Especially in areas with a lot of vegetables, maximum prices differ significantly from maize or wheat.
Figure 3: somewhere in the text above Figure 3, describe the pixel size of the land use map (see general remark).
Figure 4b: Select different colours for the flooded areas or consider reversing the colour scale for the DEM. For the 2002 maps: what about overlapping areas flooded in both events? Which of the 2 events is mapped on top of the other? Why is this not a fourth individual map? What do the results show in the next maps: the sum of both, the average, one overlaying the other event?
Figure 5: delineate the area with a line and leave the background (not selected) white to increase readability. Sealing can get a different colour, for example red to increase readability.
Figure 7a: I only see green. As pixels with high(er) water depth are probably located close to the rivers, the information is invisible. A continuous linear scale is maybe not the best choice.
Figure 5b: there’s a yellow legend class and a yellow background. Background can be removed. The legend classes result in only green colours being visible. Consider a different scale and add the maximum value to the highest legend class to indicate the range instead.
Figure 8: 0 is not bigger than 1265 and should be placed at the other end of the legend (or removed). I see some dashes of red and yellow, but a different legend choice (class boundaries, eventually adding 1 class) would indicate much better areas of attention (and in later figures where the biggest benefits are).
Figure 9 a ad b: a yellow background with a yellow legend class do not match. Background can be white. In 9b, 0 should be placed at the other end of the legend.
Figure 11: 0 at the wrong end of the legend.
Lines 371-375: it is important to mention the price of land, as this is often forgotten in nature-based solutions. The same for labour forces. Both of them can be partially mitigated (volunteers, volunteering schemes). For the subsidies: these have a cost as well, so they don’t replace the cost of land acquisition. And in addition, how likely is it that the 750 pixels selected will be the ones where the afforestation measures are applied? Planting trees is a good idea, but maybe flood reduction is not the primary benefit. I miss topics like ancillary effects (co-benefits) in a discussion that is lengthy and to the point.
Figure 12: 0 at wrong end of the legend. Can there in addition to map 12 (which will become 12a) a map 12b presenting the differences in between the 2 results visually?
Lines 442 and following: Suddenly, a new element is introduced being the flood insurance value. In my opinion it does not contribute much to the overall paper as it neglects many aspects on how insurance mechanisms work, insurance premiums, compensation values. The discussion has enough substance without this aspect.
Good luck with the research and the finalisation of the paper!