This study conducted a comprehensive analysis of the spatial and temporal variations of water resource carrying capacity (WRCC) and its influencing factors in the significant Yellow River Basin in China. Combining the composite weighting TOPSIS method with geographic detector analysis, the water resource carrying capacity index for nine provinces within the Yellow River Basin was evaluated from 2005 to 2021. The results reveal a continuous upward trend in water resource carrying capacity in the Yellow River Basin, with significant improvements attributed to increased investment in scientific research, enhanced water use efficiency, proactive water resource management, and environmental protection measures. The study also identified differences in water resource carrying capacity among provinces, highlighting the significant impact of factors such as economic development, population density, industrial wastewater discharge, and precipitation. The findings underscore the importance of balancing economic growth with environmental protection. Specifically, Inner Mongolia and Ningxia provinces showed remarkable progress, while Qinghai and Sichuan provinces exhibited slower growth, primarily due to geographical location and industrial development status. Based on these findings, it is recommended that research investment be strengthened, economic structures be optimized, water resource management be improved, and environmental protection measures be enhanced.

As a fundamental raw material industry in the industrial sector, the steel industry is the largest emitter of carbon among the 31 manufacturing sub-sectors. Assessing the sustainability level of the steel industry is thus of critical importance for advancing carbon reduction efforts. In 2024, crude steel production in Belt and Road Initiative countries reached 1.43 billion tons, accounting for 75.8% of global output. However, significant disparities exist in the development of steel industries across these countries, necessitating the construction of a robust model to evaluate their relative sustainability. This study proposes an ESG-MI evaluation model that integrates environmental, social, governance, resource, and industrial dimensions, and applies it to panel data from 64 BRI countries between 2000 and 2023 to assess the sustainability level of their steel industries. Furthermore, an obstacle degree model is employed to identify key hindering factors. The study yields the following key findings: (1) From 2000 to 2023, the sustainability level of the steel industry along the BRI showed a steady upward trend, with an average annual growth rate of 1.04%. (2) Industrial development and governance are the main drivers of sustainable development in the steel sector, while environmental performance remains a major weakness. Additionally, the resource supply chains in BRI countries are fragile and vulnerable to external shocks. (3) The sustainable development of the steel industry along the BRI follows a geographical transmission pattern of “Europe → East Asia → Middle East → Southeast Asia → South Asia.” (4) Based on obstacle degree analysis, industrial value added (X20), crude steel output per capita (X11), and the proportion of ores and metals in total exports (X12) are identified as the top three obstacles to sustainable development in the steel industry, with significantly greater hindering effects than other indicators.

This study focuses on the issue of supply security in Chinese tin resources, conducting a comprehensive analysis encompassing supply security, demand conditions, market risk, and geopolitical stability. The study employs the AHP-Entropy Weight method to calculate the comprehensive weights of various indicators, revealing the sustainable supply capability of the resources and the challenges they confront. The research unveils that the domestic supply potential and the international commercial extraction environment are pivotal influences on the sustainable supply capability of tin resources. Firstly, since 2010, China has started to import net tin ores and concentrates, leading to a substantial increase in external dependency. However, China’s tin resource reserves have gradually decreased, posing challenges to the stability of the tin resource supply. Secondly, the stability of supply countries and the security of import channels critically affect the stability of the tin resource supply chain. A comprehensive analysis of the outcomes indicates a consistent decline in China’s sustainable tin resource supply capability since 2010, primarily due to the deterioration of resource supply conditions, growth in demand, and the escalation of geopolitical risks. Thus, the evolving foreign extraction environment, domestic resource supply potential, and the alteration in the global tin resource extraction landscape require significant attention.

The steel industry in the Belt and Road region holds significant potential for development, and the systematic evaluation of its sustainable development capacity serves as a crucial foundation for improving the investment environment in the steel industry. This study focuses on the driving forces, pressures, current status, impacts, and policy responses of the steel industry, constructing an evaluation model for the sustainable development of the steel industry in the Belt and Road region. Using this model, the sustainable development capacity of the steel industry (SCSI) in 65 countries along the Belt and Road is assessed. The results indicate the following: (1) The SCSI index in the Belt and Road region has significantly increased from 18.050 in 2000 to 22.873 in 2021. (2) Since 2005, the factors influencing the spatial differentiation of SCSI in the Belt and Road region have generally followed the pathway of “industrial infrastructure → innovation environment → global governance capacity → per capita GDP,” with domestic economic level and domestic demand exerting a substantial promoting effect on the steel industry. (3) The regional differences in SCSI within the Belt and Road region are the combined result of multiple factors, with significant composite influences from indicators such as per capita GDP, population size, industrial infrastructure, and innovation environment. To further enhance the sustainable development of the steel industry along the Belt and Road, it is necessary for each country to formulate appropriate development plans based on local conditions, emphasizing strengthened international cooperation, optimized international investment environment, enhanced policy support, and improved technological level in the steel industry.

This study aims to investigate the impact of China’s Free Trade Zones (FTZs) on carbon emissions and their underlying mechanisms, addressing the following research questions: (1) Do FTZs significantly affect carbon emissions? (2) Are there spatial differences in the carbon reduction effects of these FTZs? (3) What mechanisms underlie the carbon reduction effects of FTZs? (4) Are there moderating factors that influence the effectiveness of these FTZs? Using a difference-in-differences (DID) model, this study measures the net effect of FTZ implementation on carbon emissions in 21 pilot provinces and cities in China. Additionally, it examines whether the FTZ effect shows mediating effects and introduces interaction terms to test for moderating effects. The findings are as follows: (1) The regression coefficient of FTZs on carbon emissions is −0.162, indicating that FTZs significantly reduce carbon emissions. (2) The effect of FTZs on carbon emissions varies significantly across regions, with the carbon reduction effects increasing progressively from the eastern to the central and western regions. (3) The mediating effect indicates that FTZs reduce carbon emissions by enhancing technological levels. (4) Industrial structure has a significant moderating role in the carbon emission effects of FTZs, with optimizing the industrial structure helping to suppress the increase in carbon emissions. Based on these findings, the study suggests accelerating the replication and promotion of advanced FTZ practices, strengthening carbon reduction policies driven by technological progress, and leveraging regional industrial layout adjustments to facilitate overall industrial structure upgrading.