Soil Moisture Estimate Uncertainties from the Effect of Soil Texture on Dielectric Semiempirical Models

Round 1

Reviewer 1 Report

Dear authors! I with great pleasure read your manuscript entitled “Soil Moisture Estimate Uncertainties from the Effect of Soil Texture on Dielectric Semiempirical Models”.

The dielectric property of the soil is an important parameter for microwave remote sensing. As well the dielectric models of soils are an essential part of the algorithms used for data processing in radar and radio thermal remote sensing. The study on this topic started since 1980 (for example, Rao, K.S., Chandra, G. & Raju, C.S. A comparative study of different dielectric models - computation of representative dielectric profiles of black soils. J Indian Soc Remote Sens 15, 53–63 (1987)).

The authors of presented manuscript studied the most famous models: 3 universally employed dielectric semiempirical models (SEMs), the Dobson model, the Wang-Schmugge model, the Mironov model, and a new improved SEM known as the soil semi-empirical mineralogy-related-to-water dielectric model (SSMDM).

The all sections of article (the introduction, methods, result and discussion and etc.) are well written. Only some minor changes I recommend. Please see my suggestions:

1. Table 1. The sentence must begin with a capital letter. “Deviations” instead “deviations”.
2. Table 1. What does mean the “CONETEN”? Probably is a “content”.

Thank you for your research and wish you good luck in your studies!

Author Response

Response: Thank you very much for your time spent on our manuscript and thank you for your suggestions. We have revised our manuscript accordingly.

 

Reviewer 2 Report

I believe the authors did a substantial study of the soil dielectric constant models with appropriate experimental design. However, I did not completely read through the entire manuscript because of many lengthy sentences, poor grammars as well as inappropriate words that the author used. Those make me hard to make the decision at this moment. 

Therefore, I strongly recommend the authors revise the manuscript primarily focusing on grammar checking, breaking down long sentences, and using appropriate words, etc. at this stage, and I will make the decision in the next round. 

Author Response

Response: Thank you very much for your time spent on our manuscript and thank you for your suggestions. The writing has been improved throughout the entire manuscript. Also we have had the English of our manuscript polished by an English editing service. Moreover, we have improved the part “results and analysis”

 

Reviewer 3 Report

Dear Authors

 

       

        The manuscript “Soil Moisture Estimate Uncertainties from the Effect of Soil Texture on Dielectric Semiempirical Models” could be potentially published in Remote Sensing. However, in the present state  just the beginning of work was done.

        There are important shortcomings of the work, which should be revised before publication:

 

1. The results are completely not experimentally validated. They are only the results of fairly simple simulations. The simulations need validations.
2. In above situation, the content of the article should be more specific and clear. Unfortunately, the article is not well written. It is overloaded with text and drawings and should be significantly simplified and shortened. However, unfortunately the article is not well written. It is overloaded with text and drawings and should be significantly simplified and shortened. I will give one example: Figures 5 and 6 show the results that should be experimentally validated, at least convincingly explained. But this is not done. However, unfortunately the article is not well written. It is overloaded with text and drawings and should be significantly simplified and shortened. I will give one example: Figures 4 and 5 show the results that should be experimentally validated, at least convincingly explained. But this is not done. On the contrary, there are strange effects in these drawings, e.g. sharp bends in some curves in Figure 5 that have not been explained, at all. I could give other similar examples, but it is not the role of the reviewer to explain how the article should be written.
3. The article is full of language and editorial flaws. Dozens of them (exemplary) have been marked in the attached text.
4. Some statements are wrong: for instance you write “In this paper, we focus on the theoretical aspects of the problems we attempted to solve and perform model comparisons across a wide range of soil textures without measured dielectric constant data.” However, you did neither experimental work, nor theoretical one. Only just rather simple calculations or comparisons using ready models. It is difficult to find a novelty in the manuscript

I appreciate the large amount of work done for preparing the manuscript, however it must be improved significantly before publication. The length of manuscript should be substantially reduced, some figures should be removed. If the Authors did not perform any experimental validation they should look for some datasets, which would allow them to confirm at least novel essential results.  

                                                                  Sincerely yours,

 

                                                                          Reviewer

 

Recommendation: accept after Major Revision suggested by reviewer

Comments for author File: Comments.pdf

Author Response

   The manuscript “Soil Moisture Estimate Uncertainties from the Effect of Soil Texture on Dielectric Semiempirical Models” could be potentially published in Remote Sensing. However, in the present state just the beginning of work was done.

Response: Thank you very much for your time spent on our manuscript.

        There are important shortcomings of the work, which should be revised before publication:

1. The results are completely not experimentally validated. They are only the results of fairly simple simulations. The simulations need validations.

Response: Thank you for your suggestions. We actually have employed some existing experimental data to partly prove our research, although we haven’t point it out very clearly. Except some existing experimental data, we have also given detailed theoretical analysis to support our research. Therefore, we have added some content about this in the paper as follows:

In this section, the simulations of these four models over all soil texture cases combing with some existing validations are employed to compare the difference among models and to evaluate the reliabilities of models because complex dielectric permittivity laboratory analyses performed by reproducing precise field conditions in laboratory soil samples are not easy and entirely straightforward. The soil texture cases of the existing validations are described in Table 1.

Table 1 The soil texture cases of the existing validations

Sources of measurements		sand (%)	silt (%)	clay (%)	Sources of measurements		sand (%)	silt (%)	clay (%)
From Ref [26]	Forest soil	57.4	32.1	10.5	From Ref [28]	Silt loam	8	71	21
	Natural soil	72.2	24.3	3.5	From Ref [27]	Sandy loam	62	24	14
	Sand soil	92.7	6.7	0.6		silty clay loam	11	62	27
From  Ref [13]	Harlingen clay	2.0	37.0	61.0	From Ref [7]	Sample 1	51.51	35.06	13.43
	F2	56.0	26.7	17.3		Sample 2	41.96	49.51	8.53
	H7	19.3	46.0	34.7		Sample 3	30.63	55.89	13.48
	Yuma sand	100	0	0		Sample 4	17.16	63.84	19.00
	Vernon clay loam	16.0	56.0	28.0		Sample 5	5.02	47.60	47.38
	Miller clay	3.0	35.0	62.0	From Ref [10]	Silty sand (D)	77	9	14

 

Meantime, we have added the validation to corresponding simulations.

 

1. In above situation, the content of the article should be more specific and clear. Unfortunately, the article is not well written. It is overloaded with text and drawings and should be significantly simplified and shortened. However, unfortunately the article is not well written. It is overloaded with text and drawings and should be significantly simplified and shortened. I will give one example: Figures 5 and 6 show the results that should be experimentally validated, at least convincingly explained. But this is not done. However, unfortunately the article is not well written. It is overloaded with text and drawings and should be significantly simplified and shortened. I will give one example: Figures 4 and 5 show the results that should be experimentally validated, at least convincingly explained. But this is not done. On the contrary, there are strange effects in these drawings, e.g. sharp bends in some curves in Figure 5 that have not been explained, at all. I could give other similar examples, but it is not the role of the reviewer to explain how the article should be written.

Response: Thank you for your suggestions. We have simplified and shortened the text all though the paper. We keep all the figures due to the investigation based on all soil texture cases. And sharp bends do exist when using LUT to make estimations, similar results also can be found in ref [16], and the doctoral dissertation of Gup Peng from China.

 

1. The article is full of language and editorial flaws. Dozens of them (exemplary) have been marked in the attached text.

Response: Thank you for your suggestions. The writing has been improved throughout the entire manuscript. Also we have had the English of our manuscript polished by an English editing service.

 

1. Some statements are wrong: for instance you write “In this paper, we focus on the theoretical aspects of the problems we attempted to solve and perform model comparisons across a wide range of soil textures without measured dielectric constant data.” However, you did neither experimental work, nor theoretical one. Only just rather simple calculations or comparisons using ready models. It is difficult to find a novelty in the manuscript

Response: Thank you for your suggestions. In the paper we investigate soil moisture estimate uncertainties from the effect of soil texture on dielectric semiempirical models from the theories, simulations and some existing validations, combined with the results of soil moisture estimation uncertainties from soil texture discordance and soil dielectric model discordance.

We add the more detailed information of some existing validations this time.

The theoretical analysis are described in section 3.1.1, we analyze the different ways considering soil texture for these aspects as follows: the distinction between bound water and bulk water, the dielectric properties of dry soil, the dielectric properties of bulk water, and the dielectric properties of bound water, especially for the conductivity losses included in the imaginary part of bulk water and of bound water. From the theory of the distinction between bound water and bulk water, we can find the problems of the Dobson model at low and medium volumetric water content for soil texture cases in section I, II, and IV, and also find the problems at very low volumetric water content when the sand content or clay content is large combined with the simulations over all soil texture cases. Form the theoretical treatment of the MBWF and the dielectric properties of dry soil, we find the SSMDM have better theoretical principle, and find that the Mironov model may lead to an obvious underestimation when the clay content is large combined with the simulations over all soil texture cases.

The key novelties in the manuscript are that the systematical and wide investigation soil moisture estimate uncertainties from the effect of soil texture on these four SEMs over all soil texture cases at different frequencies between 1.4 and 18 GHz for volumetric water content levels between 0.0 and 0.4 m3/m3 that the detailed information are described in Appendix, and the discussion of the applicability of these SEMs which can supply references for their choice. The existing similar investigation only focus on only two soil texture cases: soil texture cases with 60% sand and 20% clay as well as with 20% sand and 60% clay based on only simulations in [1]. Moreover, The SSMDM, the new improved model by us is introduced in this paper.

 

Ref

[1] J. Fernandez-Galvez, "Errors in soil moisture content estimates induced by uncertainties in the effective soil dielectric constant," International Journal of Remote Sensing, vol. 29, pp. 3317-3323, 2008.

 

 

Round 2

Reviewer 2 Report

The revised version looks much better than the last one. I completely go through paper thinking that it is well organized and written. I propose accept it as is. 

Reviewer 3 Report

Dear Authors,

thank you for improving the manuscript as well for your answers. I insist on my main objection that the empirical validation of the theoretical results is not sufficient as for the scientific paper. However, theoretical part is quite interesting. For this reason, taking into account your improvement and answers I would accept the manuscript for publication, if thematic editor agrees.

I still found some minor typos, as "35%. The ?' values"  in line 434, so check again English language, please during the editorial stage.

Best regards,

Reviewer