Technical and Policy Analysis: Time Series of Land Subsidence for the Evaluation of the Jakarta Groundwater-Free Zone

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper presents an interesting discussion on time series land subsidence for evaluating the Jakarta Groundwater Free Zone. The manuscript is generally well-written, but here are some suggestions for revision:

1、   In the keywords section, consider adding "Jakarta."

2、  The introduction should emphasize the relationship between land subsidence and the groundwater-free zone, as well as between land use and land subsidence, based on existing research.

3、  Move lines 207-204 after line 233 since this is the last paragraph of the introduction.

4、  Lines 236-242 need to include more data regarding Jakarta's population and area.

5、  Figures 2 and 3 lack clarity; unclear parts should be redrawn with larger font sizes.

6、  While integrating 81 ALOS-2 PALSAR-2 Synthetic Aperture Radar data provides a solid temporal framework for analyzing land subsidence, further justification for period selection and specific data processing steps would enhance methodology clarity. Additionally, comparing with other techniques (e.g., GNSS or leveling) would strengthen PS-InSAR validation.

7、  Analyzing domestic water needs in relation to land subsidence significantly contributes to understanding socio-environmental dynamics in Jakarta; however, a more detailed discussion on how demographic and socio-economic factors influence groundwater extraction and subsidence rates could improve impact. Clearer links between presented data and policy implications are also recommended.

8、  The discussion section emphasizes the key findings, particularly the misalignment of the groundwater-free zone with areas of severe land subsidence. It would be helpful to explore the broader implications for urban planning and sustainable water resource management in Jakarta. Including international best practices in groundwater management could offer valuable insights for local policymakers.

9、   The clarity of expression in English could be improved.

10、Each reference in the References section should be verified for accuracy.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

First of all, I would like to thank the editor of the journal for giving me the opportunity to review the manuscript.

 

Based on time series data, this paper analyzes the land subsidence problem in the Jakarta region and evaluates the effectiveness of the Jakarta Governor's Regulation No. 93 in 2021 through a combination of technical and policy evaluation. This paper focuses on the relationship between groundless water free areas and urban land subsidence. In general, the structure of the paper is reasonable, the logical main line is clear, the argument is reasonable, closely combined with the actual needs, and the conclusion is clear, which provides a valuable decision-making basis for the subsequent land subsidence analysis in Jakarta and the setting of groundwater resources no-mining area. However, there are still some deficiencies in the format and content of the paper, which are manifested in the following aspects.

 

Format

1. The format of the table titles and formulas in the text should be uniform, and it is recommended to fill in the center, such as the titles of Table 1 and Table 2 on page 7 and formula 2 on page 9.

2. The citation number of the Chinese citation in the main text is repeated in the same place, such as the same document is cited twice between lines 150 and 152 on page 3, and it is recommended that the citation number be placed at the end of the sentence when the literature is cited.

3. Part of the content of the star chart in Figure 2 in the text is not clear, and it is recommended to process the picture clearly.

4. Headings 2.5 and 2.6 on page 10 are repetitive, whether they are redundant and redundant, and it is recommended to clarify the relevant content.

 

Content

1. In this study, there is a lack of comparison with other technical methods in the accuracy of data processing using PS-InSAR technology, which can better reflect the reasonable effectiveness of this method, and it is suggested to add additional explanations.

2. When using GNSS to verify the accuracy and reliability of data processing, it is recommended to start from both external and internal verification, so as to fully demonstrate the reliability of data processed by PS-InSAR technology.

 

To sum up, in view of the fact that the paper has reached the level of publication in terms of structure and argumentation ideas, but there are still the above shortcomings, it is necessary to further revise the paper before publication.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The reviewed manuscript (urbansci-3458831) presents very important data, which focus on how the groundwater-free zone relates to the land subsidence in Jakarta, Indonesia. The authors used ALOS-2 PALSAR-2 satellite data (2017-2022) a time series dataset of land subsidence data, which was validated using a GPS RTK survey with an elevation of 255 points. Moreover, domestic water needs data was used to evaluate the governor's regulation on groundwater-free zones. A consequent analysis of the groundwater-free zone regulation was investigated using the land subsidence map and groundwater-free zone data. These investigations resulted in a recommendation for a new groundwater-free zone in Jakarta. I address some comments, which should be considered prior to acceptance of this manuscript:

1. Introduction; The background is thoroughly addressed in the introduction section, with citations of relevant literature. However, it is quite long; please convey it in a more concise way.
2. Line 50; “geophysical processes” please define these processes.
3. Line 79; “saturated with water and water”??
4. Line 236; replace “fascinating”.
5. Tables 1 and 2; It would be better if these tables are presented as supplementary materials.
6. Figure 2; It would be better if this figure is presented as supplementary materials.
7. Line 390; “Perissin 2016” → [90]
8. Line 320; Please support the used equation with references (here and throughout the manuscript).
9. Line 347’; “Nash and Sutcliffe 1970” Please add this to the reference list.
10. Figure 3; Please improve the quality of this figure.
11. Lines 418:422; There is no need to repeat the methods you used; instead, present your results directly (here and throughout the result section).
12. Figure 4; Please present this figure in readable form or move it to the supplementary materials.
13. Lines 436:439; This information is about methods, not results.
14. Lines 447:451; This generic speech is unnecessary here.
15. Line 455:456; “primarily in regions heavily urbanized and subjected to extensive groundwater extraction” Until here, there are no results represented related to groundwater extraction.
16. Lines 512:515 and 546:547; The mentioned names are not shown in any figures or tables.
17. The conclusion should be supported more by results.
18. Please edit references in the main text and references list according to journal guidelines.

Author Response

Please check the response, as attached

Author Response File: Author Response.pdf