Fractal development and spatial synergy of urban road network:A case study of India
The road network is a large-scale space transportation channel and a small-scale space social connection bridge,and its spatio-temporal complexity emerging mechanism has been a multi-disciplinary research hotspot.Fractal is one of the important tools to explore geo-graphical complexity.This paper collects the road networks data of the top 200 districts in In-dia's total population,excavates the geometric and structural fractal characteristics of the road networks in each district,and analyzes the statistical correlation and spatial similarities and dif-ferences of the geometric and structural fractal characteristics.The results show that:①The spa-tial distribution of the road network in the sample districts in India is uneven,maintaining the pattern of dense in the south and sparse in the north,with coastal density higher than inland.The difference between the north and the south is stronger than that between coastal and inland areas,which is consistent with the urban development pattern and the driving force of urban develop-ment in India;②The road network in all districts of India has significant geometric and structural fractal characteristics.The geometric fractal dimensions of the road networks box-covering[1.229,1.857],the structural fractal dimensions[1.623,3.179],and the fractal dimensions of the volume and degree volume structures[1.941,3.539]and[2.410,3.822],respectively,indicate that the road networks construction in most districts of India is dominated by spatial spread,thickening and densification,and three-dimensional development level needs to be strengthened,especially the cross grade and multi-layer roads are limited;③The regional linkage effect of high-grade traffic corridors is obvious,which is conducive to the coordinated development of space.