Hierarchical and coupling model of factors influencing vessel traffic flow

Zhao Liu,Zhirong Tan,Yi Liu,Zongzhi Li,Huanhuan Li,Ryan Wen Liu,Jingxian Liu,Jun Xu

doi:10.1371/journal.pone.0175840

Zhao Liu, Zhirong Tan + Show 6 more

Open Access

https://doi.org/10.1371/journal.pone.0175840

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Abstract

Understanding the characteristics of vessel traffic flow is crucial in maintaining navigation safety, efficiency, and overall waterway transportation management. Factors influencing vessel traffic flow possess diverse features such as hierarchy, uncertainty, nonlinearity, complexity, and interdependency. To reveal the impact mechanism of the factors influencing vessel traffic flow, a hierarchical model and a coupling model are proposed in this study based on the interpretative structural modeling method. The hierarchical model explains the hierarchies and relationships of the factors using a graph. The coupling model provides a quantitative method that explores interaction effects of factors using a coupling coefficient. The coupling coefficient is obtained by determining the quantitative indicators of the factors and their weights. Thereafter, the data obtained from Port of Tianjin is used to verify the proposed coupling model. The results show that the hierarchical model of the factors influencing vessel traffic flow can explain the level, structure, and interaction effect of the factors; the coupling model is efficient in analyzing factors influencing traffic volumes. The proposed method can be used for analyzing increases in vessel traffic flow in waterway transportation system.

Highlights

With the rapid development of water-transportation systems and the innovation of shipbuilding technology, the characteristics of vessel traffic flow including number, type, size, and cruising speed of vessels constantly change
A hierarchical model is proposed based on the interpretative structural modeling (ISM) model, and a coupling model that relies on weighting and quantitative indicators to analyze the relationship of factors influencing vessel traffic flow is introduced
This study introduces a hierarchical model and a coupling model of factors that influence vessel traffic flow

Summary

Introduction

With the rapid development of water-transportation systems and the innovation of shipbuilding technology, the characteristics of vessel traffic flow including number, type, size, and cruising speed of vessels constantly change. A hierarchical model is proposed based on the ISM model, and a coupling model that relies on weighting and quantitative indicators to analyze the relationship of factors influencing vessel traffic flow is introduced. The coupling model of factors that influence vessel traffic flow is established based on the impact mechanism of the factors. Step 4: Determining weights of indicators For establishing a coupling model to capture the interaction effect of influencing factors, the coupling correlation coefficient is designed and is expressed in Eq (6). The application of the hierarchical model is to establish the structural self-interaction matrix collectively for factors under navigable environment, service management, and social economy categories that influence vessel traffic flow. The main factors influencing vessel traffic volume include social economy, natural conditions, berth, route and anchorage, and natural conditions based on the hierarchical model.

Discussion

Conclusion