Soil Moisture Monitoring and Evaluation in Agricultural Fields Based on NDVI Long Time Series and CEEMDAN

Round 1

Reviewer 1 Report (Previous Reviewer 2)

Manuscript, entitled ^„ Soil Moisture Monitoring and Evaluation in Agricultural Fields Based on NDVI Long Time Series and CEEMDAN„. Research is interesting. The results show that the effect of estimating chl-a concentration by multiple regression using vegetation indices were generally better than that by regression with a single vegetation index and original band information. The CNN model obtained the best results (R²=0.7917, RMSE=8.7660 and MRE=0.2461). This study shows the reliability of using vegetation indices as an intermediate variable in the estimation of chl-a using a UAV-based multispectral data.

 

Abstract:

 

·         Line 27 to line 28. This sentence need to rephrase (2) When epsilon was 0.05 and the model type was quadratic, it was the optimal inversion model, the determination

coefficient R² was 0.98, and the model fitted better with less error).

Introduction

·         Line 71 to line 72. (There have been a large number of studies based on vegetation index long time series data of optical remote sensing images to achieve soil

moisture monitoring), could you add some details information about the previous studies for this sentence?. NDVI is mainly for water stress, estimate biomass and nitrogen in crops.

line 78. It is important to firstly separate the influence of multi-source and complexity factor; Please could you write give information about multi-source and complexity factor?

·         Line 150 to 161 . These sentences are not related to introduction section. Maybe, it is better to add in M&M

·         Line 162 to 179 for the innovations and possible contributions could be summarized as follows could be add at the end of Discussion section.

·         The authors have to present the objectives in clear points at the end of introduction.

Materials and Methods

·         Please increase the resolution of Figure 1?

·         Line 307. Chlorophyll content determination should be change to relative chlorophyll. The authors measure SPAD values and it is not chlorophyll content.

·         Line 312 and line 313. The measurement range is from 0 to 99.9 SPAD with a repeatability of SPAD up and down. This sentence is not clear. Also 99.9 SPAD in winter wheat is not true. It is very high value.

·         Please increase the resolution of Figure 3?

·         Please increase the resolution of Figure 4?

 

Results

The results were good presented.

 

Discussion

This section is still need to support by information data to cove the results and also by previous studies.

Minor editing of English language required

Author Response

Dear reviewer,

Thank you very much for taking your valuable time to review our submitted manuscript, you have given very professional and comprehensive comments that have guided the manuscript in a profound way. We have completed the revision and refinement of the manuscript based on your comments. Revisions in the revised manuscript are highlighted in green to indicate attention, and replies to each comment have been made in the pdf.

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

The MS developed an integrated method of CEEMDAN and PLSR to evaluate soil moisture based on NDVI long time series. The paper is well-written and structured. The paper could be accepted after the following issues are addressed.

1. Lines 160-170: Objectives of this study should be stated clearly.

2. Line 193: Why winter wheat was focused on in this study?

3. Lines 196-201: The heavy metal stress and fertility stress were stated here, while these stresses were not measured in this study.

4. Lines 221-228: Water resources and groundwater should be provided.

5. Line 333: Soil moisture in 5-10 cm was measured, while the value in 0-5cm was not measured, why?

6. Eq. 1 and 2: Unit should be provided.

7. Lines 351-352: what's the definition of SMSC?

8. Lines 437-457: Statistical characteristics of the NDVI should be provided.

9. Line 468: What are the three experiments?

10. Figures 6 and 7: What's the X axis?

 

Author Response

Dear reviewer,

Thank you very much for taking your valuable time to review our submitted manuscript, you have given very professional and objective comments. We have completed the revision and refinement of the manuscript based on your comments and suggestions. Revisions in the text are highlighted in green to indicate attention, and replies to each comment have been made in the pdf.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report (Previous Reviewer 2)

The authors improved the manuscript according to my comments.

It can be accepted for publication.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Concerning the introduction, the remote sensing part is very approximate. For the rest it is not very clear and as the method is tested on very limited ranges of humidity between 10 and 15% while humidity in general varies between 5 and 35% leaves me very reserved.

Comments for author File: Comments.pdf

Reviewer 2 Report

Manuscript, entitled (Soil Moisture Monitoring and Evaluation in Agricultural Fields
Based on NDVI Long Time Series and CEEMDAN). The authors reported that the utilization of CEEMDAN further enhances the accuracy of soil moistureinversion in agricultural fields, realising the effective application of remote sensing observation
technology and time-frequency analysis technology in the field of soil moisture research. There are some shortcomings that should be included in order to enhance the manuscript for the readers.

Abstract

·         Please do not use the pronouns in scientific writing?  Such as we decomposed  in line 19. ·         Please take care during the writing the most of verbs must be in the past. For example in line 21, component are calculated and line 24, the results show that.  

Keywords: should be arranged alphabetic.

Introduction

·         Several citations should be added to sentences from lines 57 to 70.

·         The NDVI is more effective by biomass amount, chlorophyll concentration, and crop stages for that why the authors focus in using it.  

·         The introduction should be shorted. Some sentences should be removed and they did not add any new information.

·         The sentences from 184 to 187 should be removed. These are the structure of the manuscript.

  Materials and methods  

·         The sections 2.1.3, and 2.2.2 should be shorted.

  Results   ·         Figures 3, 6 and 7 should be improved.

·         Please added the significant levels to Pearson correlation
coefficient in table 2 and decrease the digital number to 2 or 3.

·         Please add the significant levels to R² in tables 4 and 5.

Discussion ·         Although the authors presented the M& M, results with more details but the   discussion section is poor discussed? It should be improved. Or the authors combined results and discussion and support by several citations.   Conclusions   ·         Please write about the limitations of this work in details in conclusion section.

Moderate editing of English language required