Identification And Optimization Of Cargo Type Structure Of Port Community System From A Green Perspective

Over the past 40 years of reform and opening up,the Chinese economy has become increasingly closely integrated with the world economy,and the port has become a window representing the national economic development,urban economic growth and opening to the outside world.With the development of China's port resource integration,various provinces have coordinated multiple port resources to form a new type of port group.China's ports have grown from the Bohai Rim,the Yangtze River Delta,the southeast coast,the Pearl River Delta and the southwest coast.It has evolved into an "integrated operation" regional port cluster of "unified planning,unified construction,unified operation and unified management".How to build a regional port group with a reasonable layout,perfect functions,complementary advantages,and synergy and efficiency has become a practical problem that needs to be solved urgently for the integrated operating port group.Therefore,this article will analyze the port regional system from the perspective of community ecology under the policy support of national port integration and world-class port construction,and study the optimization of the cargo species structure of the port community system based on the green perspective.First,sort out the relevant literature on port supply and demand and competition,port community and green growth,port integration and structural optimization,and discuss the research content and significance of this article.It also briefly describes the niche,green development and other theories applied in this paper and the evolution of the port community system model.Secondly,based on the niche,construct the port group cargo species structure feature recognition model,identify the cargo species structure feature of the port community system,and select Liaoning port community for analysis.Third,combined with the current integrated transportation needs,this article builds a green port community system cargo structure optimization model that includes multiple ports,multiple cargo types,and multiple transportation modes in the hinterland.Fully consider the port cargo type structure constraints,hinterland transportation network structure constraints,and freight supply and demand balance constraints,etc.,and use fuzzy compromise changes,which is converted into a single objective model for easy solution.Finally,select the port community system in Liaoning for empirical analysis,and conduct sensitivity analysis for the functional structure adjustment and transportation structure adjustment of the port community system.The results of empirical optimization show that expanding the cargo capacity of ports with higher cargo niche can help reduce the overall cost,time and emissions of the port community system.Adjusting the transportation structure and expanding the railway share will be affected by railway loading and unloading,and the time efficiency will not be as good as cost and emissions.In the Liaoning port community system,there is fierce competition for different cargo types between ports,and different development strategies such as differentiated development,exit and focus,and win-win cooperation are required.