Study On The Spatial Structure And Spatial Equity Of Cities In The Bohai Rim Region Based On The Development Of High Speed Railway

In the context of economic globalization,the world’s urbanization process is deepening,the urban construction of each country is gradually improving,and the Bay Area economy has become a symbol of the strength of powerful countries,while the mode of transportation is also undergoing significant changes.The advent of China’s high-speed rail era,making high-speed rail has become the "go out" to the world of Chinese symbols.As the most important and critical sea port in the north of China,the Bohai Sea is of paramount importance,and the final point for developing the economy of Bohai Bay,establishing a strong economic bay area and building an integrated regional development is transportation.The development and improvement of highspeed rail network will bring significant changes to the regional economic development and spatial structure,which will inevitably bring different degrees of spatial equity,which is extremely important for regional economic integration and even regional coordinated development.Based on this background,this paper takes cities in the Bohai Sea Rim region as an example to study the changes of regional urban spatial structure and spatial equity before and after the opening of the Bohai Sea Rim.On the one hand,the impact on regional urban spatial structure before and after the opening of Bohai Rim high-speed railway is measured from three perspectives: accessibility spatial pattern,individual city centrality and regional network spatial structure.On the other hand,the spatial equity of the Bohai Sea high-speed railway before and after its opening and operation is measured in terms of the transportation equity of different regions,the social equity of transportation services for groups with unequal income and the economic equity of cities along the regional route.And constructive suggestions and development strategies are proposed for the research results.The results of the study are as follows.(1)High-speed railroads have accelerated the evolution and reshaping of the spatial pattern of urban accessibility in the Bohai Rim region,and show zonal divergence characteristics.The accessibility of cities in the Beijing-Tianjin-Hebei region is in the first place,and the overall accessibility improvement of cities in the Shandong Peninsula region is higher than that of other regions.It shows that the Bohai Sea high-speed railway will shorten the travel time distance between regional cities in a short period of time,and the more significant long-term impact will be a substantial increase in the sustainability of economic potential.(2)The spatial structure has changed from a "polycentric" pattern to a "C" type traffic axis.The overall "core-edge" characteristic of the high-speed railway axis as the core and the peripheral areas of the axis as the edge,and the divergent pattern of "high in the middle and low at the end" within the axis.The gravitational force of the new site cities is greatly enhanced,and the gravitational force of the central developed cities shows high viscosity characteristics.Although there is an asymmetry between the economic links of the Bohai Rim,the opening of the Bohai Rim high-speed railway effectively coordinates the advantages of resources in the region,making the flow of factors between cities more multiple and balanced.To a certain extent,the "siphon effect" of individual developed cities has been weakened,which is conducive to the development of cities in the region in a more coordinated direction with mutual push and interaction,forming a pattern of leading by lines.(3)High-speed railroads make the spatial equity of cities in the Bohai Rim region show different divergent characteristics,manifesting as a gradual equalization of regional urban spatial equity and relatively strong spatial inequity characteristics at different levels.Transportation fairness shows the two-sided characteristics of the overall regional fairness effect,with the coefficient of variation of the overall regional weighted average travel time rising and the coefficient of variation of economic potential decreasing.The cities in Liaodong Peninsula become the region with relatively larger benefits from the completion and opening of the Bohai Rim high-speed railway,a transportation infrastructure,while the economic potential of Shandong Peninsula benefits a lot.At the same time,the Beijing-Tianjin-Hebei urban agglomeration shows less equitable "exploitation" effect,and the spatial transportation equity of the whole region gradually tends to be equalized.The analysis of the social equity of high-speed rail travel for different income groups shows horizontal inequity and vertical equity in the distribution of inter-city rail services to residents along the route.Longitudinally,the overall urban transportation service price and consumption capacity equity of the region as a whole have been enhanced after the opening of the Bohai Rim high-speed railway.Horizontally,residents of the Beijing-Tianjin-Hebei sample cities and Liaodong Peninsula cities are superior to the Shandong Peninsula sample cities in terms of rail service prices and high-speed rail consumption ability,while residents of the Shandong Peninsula sample cities excel in terms of both improved rail service prices and high-speed rail consumption ability compared to residents of other regional cities.The completion of the Bohai high-speed railway has effectively converged the regional geographic space as a whole and brought positive economic equity effects,which are reflected in more frequent economic ties between cities and a substantial increase in total external economic ties.