Spatiotemporal Variability of Soil Water Content and Its Influencing Factors on a Microscale Slope

Round 1

Reviewer 1 Report

This manuscript investigated the spatiotemporal variability of soil water content and its influencing factors on a microscale slope. In general, the topic is of interest to the scientific community. However, there are still some questions and suggestions for this study before it can be published.

1. The spatiotemporal variability of soil water content has been addressed by several researchers. More extensive literature survey is recommended. The authors should describe more findings of previous works and illustrate the difference between the previous works and yours.

2. At the last second paragraph of the Introduction Section, the authors should present more clear research gap and novelty of this work.

3. The quality of Figs. 2, 3, 4, 5, 6 and 7 is quite low. It is difficult to identify the lines and symbols in b/w print. Please make them more readable.

4. In the results and discussions sections, the authors just describe the variations of the spatiotemporal variability. Please explain the underlying mechanism.

5. The conclusion section is lack of logic. Please present the main findings in a logical way.

6. In some places, the text is unclear and the English language used is not at high quality. A rigorous round of proofreading is highly recommended.

In some places, the text is unclear and the English language used is not at high quality. A rigorous round of proofreading is highly recommended.

Author Response

This manuscript investigated the spatiotemporal variability of soil water content and its influencing factors on a microscale slope. In general, the topic is of interest to the scientific community. However, there are still some questions and suggestions for this study before it can be published.

Thank you very much for your suggestions for this manuscript. The following are the answers to your questions.

1. The spatiotemporal variability of soil water content has been addressed by several researchers. More extensive literature survey is recommended. The authors should describe more findings of previous works and illustrate the difference between the previous works and yours.

Response: Thanks very much for your valuable comments. Previous studies on spatiotemporal variability of soil water content mainly analyzed data collected by artificial drying method, and this study analyzed high spatial resolution data observed by TDR. Previous studies mainly focused on the natural slopes of the Loess Plateau, but small-scale slopes with severe erosion have not been studied. Moreover, the research on the effect of temperature on the temporal stability of soil water is also lacking. These are discussed in the introduction.

2. At the last second paragraph of the Introduction Section, the authors should present more clear research gap and novelty of this work.

Response: Thanks very much for your valuable comments. In the last second paragraph of the Introduction section, the novelty of this work is explained. All the previous studies are based on natural hill slopes, there is a lack of research on the spatiotemporal variability of θ at the microscale slopes with fixed angle. Furthermore, in the context of severe climate change, air temperature has emerged as a significant factor affecting θ, yet it has received limited attention in the existing literature.

3. The quality of Figs. 2, 3, 4, 5, 6 and 7 is quite low. It is difficult to identify the lines and symbols in b/w print. Please make them more readable.

Response: Thanks very much for your valuable comments. Figures 2, 3, 4, 5, 6, and 7 in the manuscript have been modified.

4. In the results and discussions sections, the authors just describe the variations of the spatiotemporal variability. Please explain the underlying mechanism.

Response: Thanks very much for your valuable comments. Mechanisms affecting spatiotemporal variability in soil water content have been added to the discussion.

5. The conclusion section is lack of logic. Please present the main findings in a logical way.

Response: Thanks very much for your valuable comments. In line 521 to 530, the logic of the conclusion section has been improved and the main findings have been summarized.

6. In some places, the text is unclear and the English language used is not at high quality. A rigorous round of proofreading is highly recommended.

Response: Thanks very much for your valuable comments. The language of this paper has been proofread and improved.

Reviewer 2 Report

I find the article very interesting and the scientific problem is significant, but the manuscript needs some explanation:

1. How was estimated soil bulk density?

2. Have basic soil properties like soil texture and water retention capacity been analyzed?

3. The authors write that the texture of the soil was homogeneous, but was there any other diversity found in these soils (e.g. organic matter content)? Soils even at the microscale can have differences in e.g. organic matter content, which will affect their water properties.

Author Response

I find the article very interesting and the scientific problem is significant, but the manuscript needs some explanation:

Thank you very much for your suggestions for this manuscript. The following are the answers to your questions.

1. How was estimated soil bulk density?

Response: Thanks very much for your valuable comments. This study determined the bulk density of different soil layers using the ring knife method, which serves as fundamental data for this research.

2. Have basic soil properties like soil texture and water retention capacity been analyzed?

Response: Thanks very much for your valuable comments. In the Materials and Methods of this paper, detailed explanations are provided for soil bulk density. However, the analysis of soil texture and water retention capacity is not included in this paper. Soil texture and water retention capacity are important factors that influence temporal and spatial variability of soil water content, and their characterization can provide valuable insights into the soil water content regime. Future research should consider incorporating analysis of soil texture and water retention capacity to further enhance the understanding of soil moisture behavior in slope.

3. The authors write that the texture of the soil was homogeneous, but was there any other diversity found in these soils (e.g. organic matter content)? Soils even at the microscale can have differences in e.g. organic matter content, which will affect their water properties.

Response: Thanks very much for your valuable comments. The statement in the paper suggesting soil homogeneity is not sufficiently supported and lacks rigor. It is important to acknowledge that even on slopes with a small scale, soil heterogeneity can exist. Therefore, the statement claiming soil homogeneity in line 528 of the paper is removed. However, it is important to note that this study primarily focuses on investigating the effects of soil depth, slope position, temperature, and hydrological conditions on the temporal and spatial variability of soil water content. The analysis of soil heterogeneity is beyond the scope of this paper.