Towards Sustainable Ice–Snow Tourism: Structural Characteristics and Synergy Pathways of the Tourism Flow Network in Northeast China

Regional tourism sustainability depends on systemic resilience and synergy effects. This study constructs a tourism flow network covering the three northeastern provinces using ice–snow tourism travelogue data, and identifies sustainability bottlenecks along four dimensions: hierarchy, assortativity, transmissibility, and clustering. The results show that: ① the tourism flow exhibits a “southeastern agglomeration and central–southern polarization” pattern, with Jilin Province exhibiting the highest structural embeddedness, while Heilongjiang’s monocentric concentration implies higher systemic vulnerability; ② assortativity varies significantly across provinces—Heilongjiang demonstrates homogeneous agglomeration, which tends to amplify disturbance propagation, whereas Jilin and Liaoning exhibit cross-level linkages; ③ although intra-provincial transmission efficiency remains relatively high, the overall clustering coefficient is weak, with widespread isolated nodes and substantial cross-provincial mobility friction. Based on these diagnostics, this paper proposes tiered and spatially differentiated governance strategies: capacity–buffering measures for overloaded hub nodes, service upgrades along specific tourism corridors, and selective cooperation with culturally endowed but structurally peripheral nodes. These provide a new analytical tool and practical pathway for alleviating the spatial mismatch between tourist flows and carrying capacities, enhancing the adaptability of regional tourism systems to external shocks, and promoting the sustainable development of seasonal tourism destinations.