Research On The Characteristics Of Industrial Spatial Connection Network In The Yangtze River Delta Urban Agglomeration

Industrial spatial connection is the core of regional economic connection,which is of great significance to promote the integrated development of Yangtze river delta city clusters.Based on the induction coefficient and influence coefficient in the input-output model,this paper constructs the measurement model of industrial connection intensity of Yangtze river delta city clusters,and analyzes the industrial spatial connection intensity,industrial spatial connection direction and industrial spatial connection network structure by combining with the social network analysis method.The following conclusions are drawn:(1)The industrial connection intensity of the Yangtze river delta city clusters is relatively high on the whole,but the internal differences are significant.From the perspective of the industrial spatial connection intensity of the Yangtze river delta urban agglomeration,the average connection intensity between the two prefectural-level cities is 62791,and 60.31% of the 325 urban agglomerations are higher than the average connection intensity,indicating that the overall level of connection within the urban agglomeration is high.Of the 325 intervals,only 2 were in the first grade,13 were in the second grade,71 were in the third grade,and the largest number were in the fourth grade,239.The industrial connection intensity between Suzhou and Wuxi is 865191 at the highest,Zhoushan-Chizhou at the lowest at 5239,and the highest at 165 times at the lowest,showing an obvious gap in the industrial connection intensity within the urban agglomeration.(2)the industrial spatial connection of the Yangtze river delta city cluster is centered on Wuxi and weakened to the edge.There are 12 intervals at the edge of the Yangtze river delta urban agglomeration,and the intensity of these intervals is far lower than the average of 62791.The industrial connection intensity of the peripheral cities is relatively low,so it is the primary task to strengthen the industrial connection of the peripheral cities.Prefecture-level cities on the edge of urban agglomeration generally have a low level of connection intensity,and the area with a low level of industrial connection intensity is far away from the center of industrial connection, which is negatively correlated with distance.Although the connection intensity of the fringe cities of the Yangtze river delta city cluster is relatively low,there are two kinds of industrial connections in different prefecture-level cities,namely,the maximum strength and the second-level strength.The main contact direction radiates outward with Wuxi city as the core.The areas with high intensity of contact with Wuxi city have higher density in the east and lower density in the west.(3)Administrative barriers are still an important factor affecting industrial connections in urban agglomerations.From the perspective of provinces,the main contact direction of Shanghai is the neighboring Jiangsu province.The southern Jiangsu region in the south of Jiangsu province is adjacent to Shanghai,which is an important reserve force for the industrial transformation of Shanghai.Moreover,the economic development level of the southern Jiangsu region is similar,which is enough to realize the effective industrial contact with Shanghai.Among the 9 prefecture-level cities in Jiangsu province,the cities with the maximum intensity and the second-level intensity of 6 prefecture-level cities are still the cities in Jiangsu province,while the cities with the maximum intensity of Nanjing are the cities in Anhui province.The next level strength cities of Suzhou and Nantong are Shanghai.This shows that the main industrial contact direction of Jiangsu province is still in its own province,and most of them have not broken through the provincial boundaries.The distribution of the maximum intensity and the secondary intensity of the 8 prefecture-level cities in Zhejiang province is relatively average,and the industrial relation develops northward.(4)there are obvious high-value area,low-value area and "sag area" in the industrial spatial connection of the Yangtze river delta urban agglomeration.Yangtze river delta urban agglomeration of industry present the "Z" glyph,the overall strength of Wuxi city as the core to cut around the trend,and it also showed the following characteristics: close distance in Wuxi city prefecture level,industry overall strength shown in Wuxi city,east and west of the city industry overall strength higher than that of north and south of the city industry overall strength;The total industrial contact strength of Nantong,Yangzhou,Hangzhou,Shaoxing and Ningbo which are far away from Wuxi is higher than that of Taizhou,Xuancheng and Huzhou which are adjacent to Wuxi.