Bi-level Programming Location Optimization Of Inland Ports With Multicommodity Under Transportation Cost Uncertainty

In recent years,the rapid growth of China’s economy has created an unprecedented golden period for Chinese ports.So far,the throughput of Chinese ports occupies a larger share in the world.At the same time,fierce competition has also started among ports.In addition to strengthening infrastructure construction,some ports have successively built inland ports in inland cities.On the other hand,which can provide shippers with "one-stop"freight services such as booking space,customs declaration and inspection,so as to ease port congestion.How to build it can attract more cargo flows and avoid the impact of some uncertainties on the operation of inland ports,which makes the siting of inland ports more complicated.In view of this problem,from the perspective of maximizing the cargo flow attracted by inland ports after construction,this paper studies the location problem of inland ports with uncertain transportation costs and multiple cargo types,which can provide certain decision-making basis for the planning and construction layout of inland ports.This paper sums up Inland port related research achievements,on the basis of analyzing the lack of research,according to the fluctuation characteristics of transportation cost,respectively describes the uncertainty of highway transportation cost and cost of railway transportation in scenario set,considering the different kinds of sensitivity of the goods on time,time sensitive factor is introduced,the strategy of "different coverage radius" is proposed,at the same time considers the capacity limit of inland port,based on the inland port and the shippers of master-slave hierarchical relationship,double robust model is set up.From the perspective of builders of inland ports,the upper model aims at maximizing the expected cargo flow and offset difference attracted by inland ports after construction,while the lower model aims at minimuming the total cost including transportation cost,time cost and transit cost from the perspective of shippers.A memetic algorithm combining global search and local search is designed to solve the problem,and 32 cities in the eastern part of Inner Mongolia and three eastern provinces of China were taken as examples for solution analysis,which verified the effectiveness of the model and algorithm to some extent.The results show that:(1)In the site selection decision of inland port,from the perspective of the maximization of cargo flow,although the site selection result is inclined to choose the city with a large demand of its own,in addition to the demand and geographical location of the city,the cargo flow situation of its surrounding cities is also an important factor to be considered.(2)In the location result,road transportation cost and railway transportation cost uncertainty will influence the result of the location,when road transportation cost and the railway transportation cost rise or fall at the same time,may be the same location as a result,so in the intermodal network,it is necessary to comprehensively consider the impact of uncertainty of various transportation costs on site selection results.Compared with the existing inland ports in northeast China,the results show that the site selection results of the robust model can effectively reduce the impact of cost uncertainty on the site selection results,and the decision-makers should reasonably plan the distance between inland ports to avoid the waste of resources caused by overlapping radiation ranges when planning and building inland ports.(3)The coverage radius and capacity of the inland port have a great impact on the site selection results.Therefore,during the site selection planning of the inland port,the distribution of different types of goods around the inland port should be fully considered,at the same time,a more reasonable scale should be built to ensure the income while avoiding investment waste.