Association between ecological risks and ecosystem services in an urban agglomeration in arid China

Rapid urbanization leads to changes in ecosystem services and may exacerbate ecological risks. Clarifying the relationship between these two factors in a specific context is essential to explore the integrated management model and achieve sustainable regional development. However, previous studies mainly lack an integrated analysis, fail to clearly explain the mechanism of ecosystem change, and can neither support landscape ecological security construction nor spatial planning and management. This study, using the urban agglomeration on the northern slope of the Tianshan Mountains (UANSTM) as an example, applied multi-source data from 2010 to 2020, investigated the changes and relationships between ecological risks and ecosystem services, and proposes an assessment framework. The total ecosystem services (TES) of the studied agglomeration showed a decreasing trend, with an overall loss of 0.43%. Corresponding to the decrease of ecosystem services, the ecological risk was higher in the south and north of the UANSTM and lower in the northwestern, central, and eastern regions. The proportion of ecological high-risk areas was expanding. The key to the relationship between ecological risks and ecosystem services is the change in hydrological conditions. Therefore, we suggest that the UANSTM actively transforms the development and use mode of water resources and coordinates their allocation, aiming to reduce regional ecological risks and optimize the pattern of ecosystem services

The Spatial Pattern Evolution of Rural Settlements and Multi-Scenario Simulations since the Initiation of the Reform and Opening up Policy in China

Since the inception of China’s reform and opening-up policy, the rapidly advancing process of urbanization and the primacy accorded to urban development policies have imparted increasingly profound ramifications on rural domains. Nonetheless, antecedent research has predominantly fixated on urban sprawl, overlooking the spatial metamorphosis of rural settlements and the prospective developmental trajectories within the policy paradigm. Consequently, this inquiry endeavors to scrutinize the evolution of the spatial configuration of rural settlements in She County from the advent of reform and opening-up (1980–2020) utilizing remote sensing data. In tandem, through scenario delineation and the utilization of the CLUE-S model, it aspires to prognosticate the evolving trends in the spatial arrangements of rural settlements in She County by 2035. The empirical findings divulge that (1) The temporal progression of rural settlement spatial configurations in She County over the preceding four decades can be delineated into two discernible phases. From 1980 to 2000, alterations in the number, extent, and spatial morphological attributes of rural settlements remained circumscribed. While the count of rural settlements registered a diminution (by 3), the aggregate extent experienced a marginal augmentation (by 8.45%), concomitant with a gradual gravitation towards regular boundaries, manifesting a stochastic distribution throughout the investigation expanse. Conversely, from 2000 to 2020, the quantity and extent of rural settlements in She County underwent a precipitous augmentation (92 and 36.37%, respectively), characterized by irregular peripheries. (2) The CLUE-S model achieved an overall precision of 0.929, underscoring its applicability in emulating fluctuations in rural settlements. (3) Within the new-type urbanization scenario, the cumulative expanse of rural settlements witnessed a decline of 35.36% compared to the natural development scenario, marked by substantial conversions into grassland and urban land usage. Furthermore, orchestrated planning and directive measures have propelled the consolidation of rural settlements in She County, engendering a more equitable and standardized layout. Under the aegis of the ecological conservation scenario, the total rural settlement area recorded a 0.38% reduction vis-à-vis the natural development scenario, primarily entailing competitive coexistence with arable land, grassland, and urban land usage in spatial terms

Review of Urban Land Management Based on Bibliometrics

As the carrier of global urbanization, urban land is the basic means of productivity and life of urban residents. Urban land management is of great significance to global climate change mitigation, improving ecological quality, promoting economic development, and ensuring sustainable urban development. At present, although studies on urban land management have accumulated at the global level, the differences in research methods, objectives, and perspectives have led to the fragmentation and confusion of research conclusions. Therefore, it is necessary to review the literature of urban land management, clarify the research contexts, grasp the research progress, and predict the research trends. Bibliometrics, as a quantitative analysis method of literature review analysis, is more comprehensive and objective than relying only on a literature review. It is of great value to grasp the topics and trends of the research field from an overall perspective. In this paper, the Bibliometrix R software package was used to conduct an econometric literature analysis on urban land management from 1979 to 2021, using the Web of Science database. The results showed that: (1) the annual scientific research output and citation frequency in the field of urban land management has generally increased. Combined with the annual change trend of scientific research output, urban land management research can be divided into three stages: the budding period, from 1979 to 1989, the development period, from 1990 to 2008, and the high-yield period, from 2009 to 2021. (2) The 129 countries/regions reviewed differed in their research output, and developed countries showed strong research. The United States, China, and Australia were the top three countries in terms of solo publications and cooperation publications. In addition, among the 16,270 authors, the top three authors were Pradhan, Zhao, and Li. (3) The top three keywords in the field of urban land management were “Management”, “City/Cities” and “Land Use”. The research topics can be divided into three stages. The first stage covers studies with topics of “Management”, “Urbanization” and “GIS”, from 1979 to 2013. From 2014 to 2018, the research topics were gradually enriched by “Urbanization”, “Impact”, “System”, “GIS”, “Management”, “Policy”, “Conservation” and “land”, with a trend towards multidisciplinary and multi-perspective comprehensive analyses. From 2019 to 2021, “Management” and “Climate Change” were the main topics

Review of Urban Land Management Based on Bibliometrics

As the carrier of global urbanization, urban land is the basic means of productivity and life of urban residents. Urban land management is of great significance to global climate change mitigation, improving ecological quality, promoting economic development, and ensuring sustainable urban development. At present, although studies on urban land management have accumulated at the global level, the differences in research methods, objectives, and perspectives have led to the fragmentation and confusion of research conclusions. Therefore, it is necessary to review the literature of urban land management, clarify the research contexts, grasp the research progress, and predict the research trends. Bibliometrics, as a quantitative analysis method of literature review analysis, is more comprehensive and objective than relying only on a literature review. It is of great value to grasp the topics and trends of the research field from an overall perspective. In this paper, the Bibliometrix R software package was used to conduct an econometric literature analysis on urban land management from 1979 to 2021, using the Web of Science database. The results showed that: (1) the annual scientific research output and citation frequency in the field of urban land management has generally increased. Combined with the annual change trend of scientific research output, urban land management research can be divided into three stages: the budding period, from 1979 to 1989, the development period, from 1990 to 2008, and the high-yield period, from 2009 to 2021. (2) The 129 countries/regions reviewed differed in their research output, and developed countries showed strong research. The United States, China, and Australia were the top three countries in terms of solo publications and cooperation publications. In addition, among the 16,270 authors, the top three authors were Pradhan, Zhao, and Li. (3) The top three keywords in the field of urban land management were “Management”, “City/Cities” and “Land Use”. The research topics can be divided into three stages. The first stage covers studies with topics of “Management”, “Urbanization” and “GIS”, from 1979 to 2013. From 2014 to 2018, the research topics were gradually enriched by “Urbanization”, “Impact”, “System”, “GIS”, “Management”, “Policy”, “Conservation” and “land”, with a trend towards multidisciplinary and multi-perspective comprehensive analyses. From 2019 to 2021, “Management” and “Climate Change” were the main topics

Energy Industry Methane Emissions Trajectory Analysis in China until 2050

Methane (CH4) is an important greenhouse gas. There is increasing attention to CH4 abatement strategies because of its contribution to short-term warming and strong benefits of decreasing CH4 emissions. China greenhouse gas inventory methods are used to predict CH4 emissions from the energy industry and to assess the potentials of CH4 abatement policies and techniques by 2050. The NDC scenario results show using oil and gas as transitional clean energy sources instead of coal will increase CH4 emissions from oil and gas industries at least 70%, but CH4 emissions from the coal industry will decrease 45%, meaning total CH4 emissions from the energy industry will continually decrease at least 30% in 2030 compared with 2020. Energy-related CH4 emissions might peak around 2025, ahead of CO2 emission peaking. CH4 emissions will then decrease slightly and decrease markedly after 2030. Emissions in 2050 are expected to be 32% lower than emissions in 2020. In an extreme scenario, emissions may be 90% lower in 2050 than in 2020. It is suggested that the verification system for the energy industry’s CH4 emission accounting at the national level be improved and CH4 control targets in line with national emission targets and the “14th Five-Year Plan” development stage be formulated

Self-Assembled Three-Dimensional Microporous rGO/PNT/Fe3O4 Hydrogel Sorbent for Magnetic Preconcentration of Multi-Residue Insecticides

The purpose of this work was to develop a highly selective, sensitive, and reliable method for multi-residual analysis. A three-dimensional microporous reduced graphene oxide/polypyrrole nanotube/magnetite hydrogel (3D-rGOPFH) composite was synthesized and utilized as a magnetic solid-phase extraction (MSPE) sorbent to preconcentrate thirteen insecticides, including five organophosphorus (isocarbophos, quinalphos, phorate, chlorpyrifos, and phosalone), two carbamates (pirimor and carbaryl), two triazoles (myclobutanil and diniconazole), two pyrethroids (lambda-cyhalothrin and bifenthrin), and two organochlorines (2, 4′-DDT and mirex), from vegetables, followed by gas chromatography-tandem mass spectrometry. This method exhibited several major advantages, including simultaneous enrichment of different types of insecticides, no matrix effect, high sensitivity, and ease of operation. This is ascribed to the beneficial effects of 3D-rGOPFH, including the large specific surface (237 m2 g−1), multiple adsorption interactions (hydrogen bonding, electrostatic, π–π stacking and hydrophobic interaction force), appropriate pore size distribution (1–10 nm), and the good paramagnetic property. Under the optimal conditions, the analytical figures of merit were obtained as: linear dynamic range of 0.1–100 ng g−1 with determination coefficients of 0.9975–0.9998; limit of detections of 0.006–0.03 ng g−1; and the intra-day and inter-day relative standard deviations were 2.8–7.1% and 3.5–8.8%, respectively. Recoveries were within the range of 79.2 to 109.4% for tomato, cucumber, and pakchoi samples at the fortification levels of 5, 25, and 50 ng g−1. This effective and robust method can be applied for determining multi-classes of insecticide residues in vegetables

Assessment and Prediction of Landscape Ecological Risk from Land Use Change in Xinjiang, China

Land use change has significant impacts on the regional and global environment; thus, in-depth research on the associated ecological risks is necessary for promoting ecological restoration and sustainable development. Xinjiang, China, is characterized by a fragile ecological environment, and this study aimed to predict the land use change in the region in 2030 under different scenarios, including natural development, ecological conservation, and urban development, by using the PLUS model based on land use data from 2000, 2010, and 2020. Based on the landscape structure of regional ecosystems, we developed a comprehensive ecological risk assessment framework by utilizing a combination of landscape disturbance index, vulnerability index, and loss index. This framework allowed us to evaluate the spatiotemporal patterns and variations of landscape ecological risks under different scenarios in 2030. The study results indicate the following: (1) During the period from 2000 to 2020, the primary landscape type in Xinjiang was unused land. However, significant changes were observed in the area of cultivated land, mainly due to the conversion of grassland and construction land. The expansion of construction land during the urbanization process resulted in a decline in ecological landscapes, such as grassland, thereby weakening the ecosystem’s stability. (2) Under different simulation scenarios, the urban development scenario primarily led to the conversion of unused land into construction land, which is beneficial for economic development. On the other hand, the ecological conservation scenario resulted in a modest increase in construction land and a transformation of unused land into forest and grassland, which aligns with the principles of sustainable development. (3) Different scenarios in 2030 result in varying degrees of changes in each landscape type in Xinjiang, with the spatial distribution characteristics of landscape ecological risks remaining similar to those observed in 2020. Notably, under the urban development scenario, the area of lowest and medium risk areas decreases significantly while the area of higher and highest risk areas increases substantially. Conversely, under the ecological conservation scenario, the area of the lowest risk areas experiences a more significant increase. (4) Overall, the spatial differences in the ecological risk of Xinjiang’s landscape are significant, with HH and LL clustering types predominating and presenting a polarization pattern. The distribution pattern is low in the north and high in the central and southern parts of the study area