俄乌冲突背景下“一带一路”沿线原油海运网络 结构特征及变化分析.

The impact of international geopolitics on transportation network patterns is an important topic in economics and transportation geography. Previous studies have often overlooked the diversity of domestic crude oil transportation among countries due to limitations in statistical data, focusing mainly on national-level node selection. Additionally, the evolution of network characteristics is predominantly analyzed through long-term descriptive approaches, lacking specific contextual analyses of network evolution. This study investigates changes in the maritime crude oil transportation network along the Belt and Road Initiative (BRI) routes against the backdrop of the Russia-Ukraine conflict, offering new evidence for research in this field. Using AIS (Automatic Identification System) ship trajectory big data and complex network analysis methods, this study analyzes the overall characteristics, node importance, core-periphery structure, and clustering of the maritime crude oil transportation network along the BRI routes from 2019 to 2022. Furthermore, it examines the impact of maritime network changes on the stability of crude oil imports to China. Our findings reveal several key points. 1) The closeness, strength, and accessibility of network connections between ports show an initial increase followed by a decreasing trend. The direction of the overall network characteristic changes in the periods 2019- 2020 and 2020-2022 are opposite, with a greater magnitude in the latter period. In recent years, particularly following the Russia-Ukraine conflict, the scale-free nature of the network has continuously increased, accompanied by an increase in the concentration of crude oil shipping connections. This concentration, notably evident towards export destinations, reflects a shifting pattern in the crude oil supply demand landscape, spatially manifested as China replacing some of its crude oil shipping connections with the Middle East, thus reducing its reliance on Russian crude oil shipments. 2) The comprehensive importance of export ports has become more prominent, with a slight decrease followed by a significant increase in recent years. The importance of ports in Russia's Far East region has notably increased, reflecting a shift in Russia's crude oil export center eastward after the Russia-Ukraine conflict. The network structure transitioned from single-core to multi-core to single-core with export ports occupying more central layers. 3) Initially, there was a continuation of the core-periphery and clustering structures, but later, there was significant structural reorganization. In 2020, the core-periphery structure and clustering in terms of core ports, geographical distribution, and cluster size were largely the same as corresponding clusters in 2019; however, by 2022, a noticeable structural reorganization emerged. 4) Changes in maritime networks significantly and heterogeneously affect China's crude oil import stability. At the network level, import stability initially increases and then decreases, with the decline in the later period far exceeding that in the earlier period. At the port level, compared to ports around Bohai Bay and the Yangtze River Delta, ports along the southeastern coast, Pearl River Delta, and southwestern coast were more affected by the Russia-Ukraine conflict in terms of crude oil import stability. China responded to the risk of instability in its crude oil import network against the backdrop of the Russia-Ukraine conflict by adjusting its sources and proportions of imports from different ports. This study provides scientific evidence for a deeper understanding of the impact of geopolitical events on China's oil imports and the formulation of national energy security strategies. [ABSTRACT FROM AUTHOR]