Prediction of Ground Water Content Using Hyperspectral Information through Laboratory Test

Round 1

Reviewer 1 Report

Very good manuscript and very minor revision is required as shown in the WORD file (attached here) of this manuscript using track changes and inserted comments.

Comments for author File: Comments.pdf

Author Response

We appreciate the reviewer's comments, and the revised content is attached as a file.

Author Response File: Author Response.pdf

Reviewer 2 Report

Review of the manuscript

Prediction of Ground Water Content through Hyperspectral Information for Convenience of Construction

by

Kicheol Lee, Jeong Jun Park and Gigwon Hong

submitted for potential publication to Sustainability MDPI

Authors present the outcomes of their work to determine an equation to assess the water content within the soil which they elaborate as meritory for the earthworks and/or geotechnical works. Work is methodologically based on the application of hyperspectral information when applied to the soil sample characterised by different water content value.

Fromm y point of view, manuscript lack from a scientific foundation and presentation. It offers plenty of non relevant information which does not contribute to its scientific value. The equilibrium of the relevant information has not been reached. Contrary, authors give focus to hyperspectral information more than has been given to the content relevant from scientific point of view.

As a main outcome, authors emphasize an equation for predicting water content according to reflectance features.

At the present state the manuscript does not present real scientific contribution. Determining functional relationship between the reflectance or spectral indexes and water content of the soil sample does not offer a scientific hypothesis neither its testing. It is rather a report on the laboratory activities with conclusions strictly being valid for the experiments conducted and condition reached within the laboratory.

Manuscript aims for significant improvements to be assessed as original research paper.

Below I attach several additional specific comments to be improved by authors.

Major:

Chapter 2 Hyperspectral information is not neccesarry. It does not represent any relevant information for the work. The content is of general purpose and describes HI in general manner, offering information which are not relevant for the methodology.

Chapter 3 – Rather to rename to Methodology.

What is the meaning of water content [%]? Does it fit the saturation definition? How the water content has been assessed within samples?

Please specify the way how different water content values have been reached and ensured?

Reflectance has been observed for soil sampled at different water content values rangeing from 1 to 21 %. What in case of higher water content values – can the presented outcome be generalized and extrapolated although non linearities are present within the final equation presented as a result?

In total six spectrum indexes have been taken into consideration from the literature and reflectance results have been used depending on the water content for a range of wavelengths 680 – 800 nm app. Than eq. (7) has been used to normalise the influence of water content variabilities to various indexes. What is the idea of this work?

Discussion is written in a form of Results. It actually represents results rather than discussion.

Discussion section is mandatory to strengthen the findings of the study. Specific issues have to be found (at least):

i)                    What is the practical merit of the findings arose from the work performed by authors?

ii)                   In case of in-situ application – how the inhomogeneities found in natural conditions of the soil affect the generality of the results presented within the manuscript? Changes in the soil type or structure will affect the reflectance spectrum.

iii)                 More on the selected relevant wavelengths must be elaborated. Since values shown in Figure 12 are mostly constant (for water content values 2-15 %), what would be the consequence if for instance wavelength 500 nm is used? The selection of relevant wavelengths seem to be done ad hoc by the user in situ which could significantly influence the validity of the equations in Table 3..

Author Response

We appreciate the reviewer's comments, and the revised content is attached as a file.

Author Response File: Author Response.pdf

Reviewer 3 Report

This is an exciting and excellent paper. The reviewer appreciates the author's new thinking and careful technical treatment, fully agrees to publish this paper as soon as possible, and expects the technology presented in this paper to be applied in practice as soon as possible.

Author Response

We appreciate your review, and we will try to publish it through a quick revision.

Round 2

Reviewer 2 Report

 

Dear authors, I carefully checked the updated manuscript version as well as your responses. Below I am sending a replies to Your Reply to reviewer. In some specific points the manuscript has been improved. Still, some relevant key issues have to be improved. 

Following the explanations from your responses I suggest more strict title definition. Instead of "Prediction of Ground Water Content through Hyperspectral Information for Convenience of Construction " a modification suggested is "Prediction of Ground Water Content through Hyperspectral Information for the laboratory prepared soil samples".

 

 

1.  HI is something not being new today. Today, Hi hardware is offered worldwide and users can approch easily. Thy way how Chapter 2 is written is of general manner and does not fit scientific publication, if this is the aim of the authors. Several information, if authors see them relecant and crucial for the paper, can be implemented into Introduction section.

 

2. OK.

3.  The intention here is to elaborate the experiments control. If the HI reflectance has been obtained for different water content values, the question is how the relevant water content is reached. For instance, the aim is to prepare a sample with 5 5 water content, how this value is ensured during the sample preparation. What ensures the value is not 5.10? What is the accuracy of the procedure to ensure the fixed water content value?

4.  Since the paper relies on different HI reflectance features of the samples containing different water content, elaboration on the procedure to reach and ensure different water content values is mandatory.

5.  OK.

6.  Hereby , I wish to elaborate my question and make it clear to authors. As I see, the eq. 7 has not been used in Chapter 4 (it wasn’t mentioned). So, what is the relevance of eq. 7 to obtain results shown in Chapter 4.? Same results could have been obtained without mentioning eq. 7 within the manuscript.

7.  Chapter 5 presents now strictly Discussion form with a very low Result facts. Please divide those two sections and separate results from Discussion.

8. OK.

 

 

Author Response

The corrections have been attached.

Thanks for the reviewer's comments.

Author Response File: Author Response.docx