Dynamic Social Risk Assessment for Inland Waterway Lock Reservation Scheduling: A Stakeholder-Informed Dynamic Weighting and Two-Dimensional Cloud Model

Inland waterway locks are critical navigation infrastructures in waterborne transport systems, and their operational reliability is closely associated with the resilience and service capacity of regional inland waterway networks. As lockage demand continues to increase, reservation scheduling has emerged as an important institutional and operational instrument for improving traffic organization, alleviating congestion, and enhancing the adaptive capacity of lock operations. However, the implementation of reservation-based rules may reshape lockage resource allocation, priority mechanisms, vessel arrival patterns, and stakeholder benefit structures, thereby generating social risks that cannot be adequately captured by conventional engineering safety assessment methods. To address this issue, this study develops a stakeholder-informed dynamic social risk assessment framework for inland waterway lock reservation scheduling. First, a hybrid scheduling mode combining priority reservation and declaration-based queuing is conceptualized, and its operational process is characterized through lockage resource allocation, vessel reservation/declaration, coordinated water-area control, anchorage and safety inspection, and sequenced vessel lockage. Second, drawing on the social amplification of risk framework, a social risk assessment indicator system is constructed from four dimensions: legality, rationality, feasibility, and controllability. Third, a Dynamic Weighting Model is introduced to adaptively update indicator weights according to changes in scheduling rules and operational states, while a Two-Dimensional Cloud Model is developed to jointly represent risk probability and risk consequence under uncertainty. The proposed approach is validated using the reservation scheduling scenario of the Three Gorges locks. The results indicate that the overall social risk is classified as level 2, corresponding to a moderately low risk level, suggesting that the reservation scheduling mode is generally compatible with lock operation and navigation management requirements. Among the four dimensions, controllability exhibits the highest relative risk, indicating that greater attention should be paid to safety management, reservation compliance, public opinion guidance, and emergency response. The proposed framework provides a systematic and visual decision-support tool for risk identification, risk grading, and scheme optimization in inland waterway lock reservation scheduling.