Importance of the Influence of Drained Clay Soil Retention Properties on Flood Risk Reduction

Round 1

Reviewer 1 Report

This paper made massive field experiments in order to determine the impact of drained clay soil retention properties on flood risk. The study is interesting to the hydrological communities. However, this paper lacks theoretical contributions since the entire paper just explores the different case studies and the interactions among rainfall, drainage, and soil moisture variations. No general conclusions have been drawn deep to a theoretical level. Therefore, this paper should be reconsidered after doing a major revision. I suggest that the authors narrow down the study and go deeper and improve this paper to a theoretical level.

Minor Comments:
- The title of the paper contains flood risk and the impact of soil retention properties on reducing it. However, in the manuscript, rarely we can see results related to this title. For example, the manuscript has the motivation of this question that to what extent, the drainage system can improve the soil retention properties and hence reduce the flood risks. However, nor in the results part, and neither in conclusions, we cannot find the answer to this question. I suggest the author add some paragraphs/results associated with the answer to the mentioned question.

- I suggest the author update the introduction of the paper with including the innovation of the study, the last paragraph of the introduction requires more sentences that shows what has been done in this paper for the first time that has not been done in the literature before.

- Currently, the results and methodology part are mixed and there are some new equations that are introduced for the first time in the results part. I suggest the author update the structure of the paper and separate methodology and results in the manuscript. (e.g., equations 1 and 2).

- Figure 4,6,8; What is the utility of these figures? I suggest the author add some motivation in the methodology part to support these results. In the current format of the manuscript, the readers might not understand what they need to learn from these figures.

- In Table 1, there are two variables introduced (i.e., PRR and DF). Please try to introduce them in the methodology part using some motivation in utilizing them.

- Figure 9: Please try to introduce this graph and its applications in the introduction and methodology parts. It would be valuable to validate this graph as well as using other datasets available at different times that have not been used in the development of it.

Author Response

Thank you very much for careful study of the article and valuable comments.

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

In the Introduction section should be extended the history of floods in Poland should be extended before 1997.

Author Response

Thank you very much for your comment.

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

General comments

I very much enjoyed reading this paper. Scientists who devote themselves to experimental studies are real heroes!

The paper is a field study for a small catchment in an agricultural setting with a tile drainage system. The author has measured the major components of the water balance except for the evaporation which is calculated based on meteorological measurements. The study seems to have been made in a careful and meticulous way. The results are not revolutionary but very useful.

My objections are linked with the analysis. In order to make the water balance work the author has to introduce some elements, interaction with the area outside the study area, which have not been measured. I think that there are some uncertainties in the measured water balance which should be explored in the analysis. Also, more explanation and analysis of the interaction with the outside is warranted. More details are found below.

Major comments

• There are four groundwater measuring wells. However, it is not clear which one that is used to represent the groundwater table. Or maybe some kind of average is used? This needs to be clarified, and should also be discussed.
• There is only one point for observation of soilwater content. It is not clear how it relates to the groundwater observation due to the missing info about groundwater measurements – see previous bullet. Furthermore – how representative is this one point for the whole catchment? This should also be discussed
• The evaporation seems to be a major source of uncertainty in the study. The procedure (calculation) needs to be explained in more detail. The uncertainty in estimating evaporation must be discussed in the analysis/discussion part.
• The terms referring to the interaction with the area outside the catchment need to be explained in more detail and discussed more in the analysis/discussion, see Table 1 “Other factors”. Some examples below.
• In Table 1, why is the surface flow across the catchment boundary directed outward during the first period and inward during the last period. What exactly is referred to by the term “seepage”?
• The section (starting line 32) with a general introduction about flooding is not very good. And I cannot see why it is necessary at all. It can be shortened a lot.

Minor comments

• line 36 / The word “violence” is not properly used here.
• Line 56 / technical and semi-technical is new terminology for me
• Line 77-78 / I think that this study can be motivated also by its contribution to basic knowledge about the water balance and associated processes for a field with tile drainage
• I am not comfortable with the unit m3/ha. I would prefer the unit mm. It has been used in the paper in association with rain data.
• Why is response time not given in hours, see e.g. Fig 7? The author uses days. But, as I understand the measurements are made with much higher time resolution.
• In case 3 there was precipitation as snow and snow on the ground for some time. I do not think that the author has presented any temperature measurements for the melt period. And no precise presentation of the melt process, like for example the time it took for all snow to melt.
• Line 230 / I think that the definition of prr and df (eq. 1,2,3) should be given in text right after line 230. It seems like (but it is not totally clear) that they are part of the Table 1

Author Response

Thank you very much for your warm words in your first comment and the other valuable and constructive comments which have helped me improve the article.

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The author has almost covered all of my comments satisfactory. I have some minor comments that are necessary to be applied to the manuscript before its publication:

Line 80 to 84: the newly inserted text is really hard to follow up. Please try to re-write this part. For example, “In this paper undertaken probe of approach of.. approach of what?” or “The time of spring thaws, … was taken into account for what?” or “two values are introduced… to do what?”

Line 184: Please provide the general form of the exponential function using some alphabets (e.g., a or b) and show the values of the equation as 0.0546 and 6.1295 in the results section.

Author Response

Thank you for your comments and suggestions.

Author Response File: Author Response.pdf