Ecological Risk Assessment of Land Use Change in the Tarim River Basin, Xinjiang, China

Round 1

Reviewer 1 Report

The paper addresses the issue of reduced ecosystem service supply under current global climate change, selecting the Tarim River Basin in Xinjiang as the research area. It evaluates the ecological risks of land use changes by combining the PLUS model and the Invest model. This methodological innovation offers a new research perspective and tool. The paper details the quantitative methods of ecosystem services, including calculations of carbon storage, water yield, soil conservation, and habitat quality, as well as the quantification of the PLUS model and ecological risk indicators, demonstrating solid research methods and rigorous data analysis.

Recommendations for revisions are as follows:

1. The abstract is recommended to be appropriately reduced in length.

2. The table on page four should be provided with a table number and title.

3. It is suggested to add some comparative analysis with other studies related to dry region basins in the discussion section.

4. Consistency needs to be maintained as to the abbreviation of the journal name in the references.

5. Carefully check the details in the article,like “Dem” in table 1 should be DEM.” Yu Wen et al.” Should be Yu et al.”Percentage of Change”in table 4 should be Percentage of change

Carefully check the details in the article and improve the English.

Author Response

Response to Editor and Reviewers

April 15, 2024

Journal name: Land

Manuscript title: Ecological Risk Assessment of Land Use Change in the Tarim River Basin, Xinjiang, China (Manuscript ID: land-2955264)

Dear Editors and Reviewers:

We thank you very much for giving us an opportunity to revise our manuscript, we appreciate the reviewers very much for their positive and constructive comments and suggestions on our manuscript entitled “Ecological Risk Assessment of Land Use Change in the Tarim River Basin, Xinjiang, China” (Manuscript ID: land-2955264). We modify them one-by-one by point, as shown in the red part of the reworked version. We study the comments carefully and make revision which we hope meet with approval.

Independent Review Report, Reviewer 1

The paper addresses the issue of reduced ecosystem service supply under current global climate change, selecting the Tarim River Basin in Xinjiang as the research area. It evaluates the ecological risks of land use changes by combining the PLUS model and the Invest model. This methodological innovation offers a new research perspective and tool. The paper details the quantitative methods of ecosystem services, including calculations of carbon storage, water yield, soil conservation, and habitat quality, as well as the quantification of the PLUS model and ecological risk indicators, demonstrating solid research methods and rigorous data analysis.

Recommendations for revisions are as follows:

1. The abstract is recommended to be appropriately reduced in length.

Response: Thanks. We revised and streamlined the abstract as requested.

Abstract: In recent years, global climate change and human alterations to land use have led to a decrease in ecosystem services, making ecosystems more vulnerable. However, unlike the well-established risk assessment frameworks used in natural disaster research, the concept of ecological risks arising from changes in land use is still in its early stages, with its nuances and assessment methodologies yet to be clearly defined. This study proposes a new framework for assessing ecological risks resulting from changes in land use in the Tarim River Basin. The framework employs a coupled PLUS and Invest model to evaluate the ecological risks of land use change under three development scenarios projected for the Tarim River Basin in Xinjiang by 2035. The findings indicate that: (1) Between 2000 and 2020, the predominant land use types in the Tarim River Basin in Xinjiang were primarily unused land, followed by grassland and cropland. Conversely, grassland, water, and construction land were relatively less prevalent. During this period, the area of unused land and cultivated land increased, while grassland, forest land, and water exhibited a declining trend. Moving forward, under the three scenarios from 2020 to 2035, land use changes in the study area are characterized by the expansion of cropland and unused land, coupled with a significant decrease in grassland area, while other land categories demonstrate minor fluctuations; (2) From 2020 to 2035, across various scenarios, the total ecosystem service within the study area demonstrates an overall increasing trend in both the northern and southern marginal zones. Specifically, under the baseline scenario, the total amount of ecosystem services in the study area decreased by 15.247% compared to 2020. Similarly, under the economic development scenario, this decrease amounted to 13.358% compared to 2020. Conversely, under the ecological protection scenario, the decrease reached 19.852% compared to 2020; (3) The structure of ecological risk levels from 2020 to 2035, across multiple scenarios, demonstrates a consistent pattern, characterized by a predominant proportion of moderate risk. Conversely, other risk levels occupy relatively smaller proportions of the area.

2. The table on page four should be provided with a table number and title.

Response: Thanks. We have verified and modified them as required. Table 1. Land use change ecological risk data characterization.

3. It is suggested to add some comparative analysis with other studies related to dry region basins in the discussion section.

Response: Thanks. We have verified and modified them as required.

5.2. Comparison with Previous Research

Currently, the ecological risks of land use changes in the TRB have not been assessed. This study integrates simulated land use results and ecosystem services into ecological risk assessment by introducing the economic Sharpe ratio [33].

Extensive research has been conducted on the ecosystem services of the TRB. The ecological security assessment, based on ecological footprint, indicates that water scarcity is a significant constraint on the socio-economic development of the TRB. This is exacerbated by climate change and rapid cropland expansion. Furthermore, the significant growth of artificial ecosystems, referred to as artificial oases, resulting from the transformation of natural oases or deserts, worsens landscape fragmentation and the ongoing degradation of ecological security levels in the basin. The increase in ecological risks due to water scarcity is consistent with the findings of this study, primarily resulting in a gradual rise in ecological risks in the transitional zones between cropland and forests. The TRB indicates an overall increase in ecosystem vulnerability levels, with some areas experiencing extremely severe vulnerability. This finding is consistent with the gradual rise in ecological risk levels discussed in this study. The evaluation of ecological risks resulting from ecosystem degradation shows a significant correlation between these risks and the swift urbanization and expansion of cropland, which are the primary drivers of ecological risks in the TRB [51].

The study shows that the spatial distribution of ecological risk resulting from land use change in the TRB is closely aligned with the spatial distribution pattern of ecosystem service functions in the TRB after the implementation of ecological restoration projects, as described in other studies [52]. This suggests that human activities significantly influence land use change-induced ecological risks.

4. Consistency needs to be maintained as to the abbreviation of the journal name in the references.

Response: Thanks. We have verified and modified them as required.

1. Omar, H.; Cabral, P., Ecological risk assessment based on land cover changes: A case of Zanzibar (Tanzania). Remote Sens 2020, 12, (19), 3114.
2. Tian, P.; Li, J.; Gong, H.; Pu, R.; Cao, L.; Shao, S.; Shi, Z.; Feng, X.; Wang, L.; Liu, R., Research on land use changes and ecological risk assessment in Yongjiang River Basin in Zhejiang Province, China. Sustain 2019, 11, (10), 2817.
3. Wang, D.; Ji, X.; Li, C.; Gong, Y., Spatiotemporal variations of landscape ecological risks in a resource-based city under transformation. Sustain 2021, 13 (9), 5297.
4. Li, J.; Pu, R.; Gong, H.; Luo, X.; Ye, M.; Feng, B., Evolution characteristics of landscape ecological risk patterns in coastal zones in Zhejiang Province, China. Sustain 2017, 9, (4), 584.
5. Heenkenda, M.K.; Bartolo, R., Regional ecological risk assessment using a relative risk model: A case study of the Darwin Harbour, Darwin, Australia. Hum Ecol Risk Assess 2016, 22, (2), 401-423.
6. Kanwar, P.; Bowden, W.B.; Greenhalgh, S., A regional ecological risk assessment of the Kaipara Harbour, New Zealand, using a relative risk model. Hum Ecol Risk Assess 2015, 21, (4), 1123-1146.
7. Du, X.; Lin, X., Conceptual model on regional natural disaster risk assessment. Procedia Eng 2012, 45, 96-100.
8. Liang, X.; Guan, Q.; Clarke, K.C.; Liu, S.; Wang, B.; Yao, Y., Understanding the drivers of sustainable land expansion using a patch-generating land use simulation (PLUS) model: A case study in Wuhan, China. Comput Environ Urban 2021, 85, 101569.
9. Congjuan, L.; Abulimiti, M.; Jinglong, F.; Haifeng, W., Ecologic service, economic benefits, and sustainability of the man-made ecosystem in the taklamakan desert. Front Env Sci 2022, 10, 813932.
10. Xu, D.; Cheng, J.; Xu, S.; Geng, J.; Yang, F.; Fang, H.; Xu, J.; Wang, S.; Wang, Y.; Huang, J., Understanding the relationship between China’s eco-environmental quality and urbanization using multisource remote sensing data. Remote Sens 2022, 14, (1), 198.
11. Meng, Z.; Dong, J.; Ellis, E.C.; Metternicht, G.; Qin, Y.; Song, X.; Löfqvist, S.; Garrett, R.D.; Jia, X.; Xiao, X., Post-2020 biodiversity framework challenged by cropland expansion in protected areas. Nature Sustain 2023, 6, (7), 758-768.
12. Carefully check the details in the article,like “Dem” in table 1 should be DEM.” Yu Wen et al.” Should be Yu et al.” Percentage of Change”in table 4 should be Percentage of change

Response: Thanks. We have verified and modified them as required.

Carefully check the details in the article and improve the English.

Response: Thanks. We have verified and modified them as required.

Thank you again for your valuable comments. I hope my reply can get your approval.

With best regards,

                                                                  Sincerely yours,

                                                                       Wei Song

Author Response File: Author Response.docx

Reviewer 2 Report

This manuscript is an important tool to making decisions and modelling impact on ecosystem services at whatershed scale, with limitations as authors mentioned about imposibility to model future scenarios, still is a good tool to value ES at this broad scales.

Author Response

Response to Editor and Reviewers

April 15, 2024

Journal name: Land

Manuscript title: Ecological Risk Assessment of Land Use Change in the Tarim River Basin, Xinjiang, China (Manuscript ID: land-2955264)

Dear Editors and Reviewers:

We thank you very much for giving us an opportunity to revise our manuscript, we appreciate the reviewers very much for their positive and constructive comments and suggestions on our manuscript entitled “Ecological Risk Assessment of Land Use Change in the Tarim River Basin, Xinjiang, China” (Manuscript ID: land-2955264). We modify them one-by-one by point, as shown in the red part of the reworked version. We study the comments carefully and make revision which we hope meet with approval.

Independent Review Report, Reviewer 2
This manuscript is an important tool to making decisions and modelling impact on ecosystem services at whatershed scale, with limitations as authors mentioned about impossibility to model future scenarios, still is a good tool to value ES at this broad scales.

Response: Thank you for recognising the ecological risk of land use change research.

Thank you again for your valuable comments. I hope my reply can get your approval.

With best regards,

                                                                  Sincerely yours,

                                                                       Wei Song

Author Response File: Author Response.docx

Reviewer 3 Report

  The basic science of this paper is carried out in a good manner with proper standards. The author and his team have written this paper according to the scope of the journal and modern trends. I am happy to review this paper as it is related to my research. If the authors want to publish this study, they should provide some novelty or enhance the significance of the study. And authors should check all figures before final publication. 

1. The author should revise several paragraphs of the introduction. The introduction section draws out the environmental significance and purpose of this paper by extracting research questions and useful information from the literature and pointing out the shortcomings of previous studies.

2. what is the significance of selecting the study area?

3. Figure 1: I think it is necessary to explain the sub icons in the figure header because the author did not explain them neither in the figure header nor in the text.

4. Authors should reorganize this title according to international journal standards. Need to move 2.3 Research Framework to 3. Methodology section.

5. This article uses land use data for the years 2000, 2010 and 2020 with a 10 year interval between each period. However, in my experience, it is common practice for articles to use data with 5-year intervals. Longer intervals may result in lower credibility. Therefore, authors should provide a convincing explanation for this deviation from the usual practice, especially given that land use data are readily available.

6 In the discussion section, please add comparisons with existing studies, demonstrate strengths and limitations, and again articulate the novelty of the literature and support for the argument.

Some sentences are very long. Authors should split them when revising the version.

Author Response

Response to Editor and Reviewers

April 15, 2024

Journal name: Land

Manuscript title: Ecological Risk Assessment of Land Use Change in the Tarim River Basin, Xinjiang, China (Manuscript ID: land-2955264)

Dear Editors and Reviewers:

We thank you very much for giving us an opportunity to revise our manuscript, we appreciate the reviewers very much for their positive and constructive comments and suggestions on our manuscript entitled “Ecological Risk Assessment of Land Use Change in the Tarim River Basin, Xinjiang, China” (Manuscript ID: land-2955264). We modify them one-by-one by point, as shown in the red part of the reworked version. We study the comments carefully and make revision which we hope meet with approval.

Independent Review Report, Reviewer 3
The basic science of this paper is carried out in a good manner with proper standards. The author and his team have written this paper according to the scope of the journal and modern trends. I am happy to review this paper as it is related to my research. If the authors want to publish this study, they should provide some novelty or enhance the significance of the study. And authors should check all figures before final publication.

1. The author should revise several paragraphs of the introduction. The introduction section draws out the environmental significance and purpose of this paper by extracting research questions and useful information from the literature and pointing out the shortcomings of previous studies.

Response: Thank you. Landscape ecological risk assessments often overlook the structure and functionality of the ecosystem, focusing solely on the landscape perspective. Despite the fact that the landscape represents only a small portion of the entire ecosystem, assessments are typi-cally static, failing to account for the dynamic nature of land use changes. As a result, landscape ecological risk assessments do not adequately capture the fluctuations in eco-logical risks associated with land use changes. Current risk assessment methodologies only consider the impact of baseline land use changes, without exploring the potential transitions between different land use types and ignoring future risks. Therefore, a new approach is needed to evaluate the ecological risks associated with land use changes, ca-pable of addressing the dynamic alterations in land use and the complex nature of eco-systems.

The Tarim River Basin (TRB) is located in an extremely arid region of China and is heavily influenced by dry climates and intense human activities. As a result, significant alterations in ecological processes have occurred, leading to a heightened ecological vulnerability (EV). Furthermore, rapid urbanization and extensive cropland development in the region have resulted in dramatic changes to the ecosystem. The study's logical frame-work focuses on analyzing and simulating land use changes, assessing ecosystem service functions, and spatially identifying and evaluating ecological risks. To achieve this, we coupled the PLUS and Invest models [32] to simulate potential future scenarios of land use changes in the TRB under three development scenarios for the year 2035: baseline development, economic development, and ecological conservation. The economic Sharpe ratio [33] is subsequently introduced to integrate land use simulation results and ecosystem services into ecological risk assessment. This study provides empirical evidence for eco-logical risk assessment in the TRB by analyzing the spatiotemporal differentiation of eco-logical risks associated with land use changes under the three development scenarios for 2035 and exploring their attribution. It also offers technical support and a multi-level re-search approach for similar study areas.

2. what is the significance of selecting the study area?

Response: Thank you. The Tarim River Basin, located in the arid expanse of northwestern China, is the linchpin of the Silk Road Economic Belt. The region is rich in natural resources, but struggles with ecological fragility exacerbated by its arid climate. The conundrum between socio-economic progress and ecological integrity is exacerbated by climate variability and rapid agricultural expansion. In particular, the expansive proliferation of artificial oases exacerbates the fragmentation of land-use patterns and accelerates the ongoing degradation of ecological security. Therefore, this study focuses on the Tarim River Basin.

3. Figure 1: I think it is necessary to explain the sub icons in the figure header because the author did not explain them neither in the figure header nor in the text.

Response: Thanks. We have verified and modified them as required. Figure 1. Overview of the study area. (a) China, (b) Tarim River Basin countries, (c) Tarim River Basin DEM

4. Authors should reorganize this title according to international journal standards. Need to move 2.3 Research Framework to 3. Methodology section.

Response: Thanks. We have verified and modified them as required.

5. This article uses land use data for the years 2000, 2010 and 2020 with a 10 year interval between each period. However, in my experience, it is common practice for articles to use data with 5-year intervals. Longer intervals may result in lower credibility. Therefore, authors should provide a convincing explanation for this deviation from the usual practice, especially given that land use data are readily available.

Response: Thank you. We have added data limitations to the discussion section.

This paper chose a land use interval of 10 years per stage, which was not specific enough for the response of economic development to land use. Therefore, we will conduct land use research with a time interval of 5 years in the future stage.

6 In the discussion section, please add comparisons with existing studies, demonstrate strengths and limitations, and again articulate the novelty of the literature and support for the argument.

Response: Thank you. We have reviewed and modified them as necessary. By reviewing the literature, we have refined the introduction, which encapsulates the innovative points of this manuscript and summarizes its research content. In the Discussion section, a comparative analysis of the work of other researchers will be conducted, and the ecological risks of land use change will be explored.

1. Introduction

Landscape ecological risk assessments often overlook the structure and functionality of the ecosystem, focusing solely on the landscape perspective. Despite the fact that the landscape represents only a small portion of the entire ecosystem, assessments are typically static, failing to account for the dynamic nature of land use changes. As a result, landscape ecological risk assessments do not adequately capture the fluctuations in ecological risks associated with land use changes. Current risk assessment method-ologies only consider the impact of baseline land use changes, without exploring the potential transitions between different land use types and ignoring future risks. Therefore, a new approach is needed to evaluate the ecological risks associated with land use changes, capable of addressing the dynamic alterations in land use and the complex nature of ecosystems.

The Tarim River Basin (TRB) is located in an extremely arid region of China and is heavily influenced by dry climates and intense human activities. As a result, significant alterations in ecological processes have occurred, leading to a heightened ecological vulnerability (EV). Furthermore, rapid urbanization and extensive cropland development in the region have resulted in dramatic changes to the ecosystem. The study's logical framework focuses on analyzing and simulating land use changes, assessing ecosystem service functions, and spatially identifying and evaluating ecological risks. To achieve this, we coupled the PLUS and Invest models [32] to simulate potential future scenarios of land use changes in the TRB under three development scenarios for the year 2035: baseline development, economic development, and ecological conservation. The economic Sharpe ratio [33] is subsequently introduced to integrate land use simulation results and ecosystem services into ecological risk assessment. This study provides empirical evidence for ecological risk assessment in the TRB by analyzing the spatiotemporal differentiation of ecological risks associated with land use changes under the three development scenarios for 2035 and exploring their attribution. It also offers technical support and a multi-level research approach for simi-lar study areas.

5.2. Comparison with Previous Research

Currently, the ecological risks of land use changes in the TRB have not been assessed. This study integrates simulated land use results and ecosystem services into ecological risk assessment by introducing the economic Sharpe ratio [33].

Extensive research has been conducted on the ecosystem services of the TRB. The ecological security assessment, based on ecological footprint, indicates that water scarcity is a significant constraint on the socio-economic development of the TRB. This is exacerbated by climate change and rapid cropland expansion. Furthermore, the significant growth of artificial ecosystems, referred to as artificial oases, resulting from the transformation of natural oases or deserts, worsens landscape fragmentation and the ongoing degradation of ecological security levels in the basin. The increase in ecological risks due to water scarcity is consistent with the findings of this study, primarily resulting in a gradual rise in ecological risks in the transitional zones between cropland and forests. The TRB indicates an overall increase in ecosystem vulnerability levels, with some areas experiencing extremely severe vulnerability. This finding is consistent with the gradual rise in ecological risk levels discussed in this study. The evaluation of ecological risks resulting from ecosystem degradation shows a significant correlation between these risks and the swift urbanization and expansion of cropland, which are the primary drivers of ecological risks in the TRB [51].

The study shows that the spatial distribution of ecological risk resulting from land use change in the TRB is closely aligned with the spatial distribution pattern of ecosystem service functions in the TRB after the implementation of ecological restoration projects, as described in other studies [52]. This suggests that human activities significantly influence land use change-induced ecological risks.

Some sentences are very long. Authors should split them when revising the version.

Response: Thanks. We have verified and modified them as required.

Thank you again for your valuable comments. I hope my reply can get your approval.

With best regards,

                                                                  Sincerely yours,

                                                                       Wei Song

Author Response File: Author Response.docx