The Analysis of Urban Expansion Based on Space Syntax: A Case Study of the Main Urban Area of Hangzhou, China

As China’s urbanization enters a rapid development stage, the expansion of cities has generated several problems. The road network influences urban form significantly and can contribute to sustainable urbanization. Currently, studies on urban expansion rarely use road networks. This study aims to analyze the spatial aggregation and intensity of urban expansion using road network data by space syntax. The results of spatial autocorrelation analysis show a moderate degree of positive spatial autocorrelation in the main urban of Hangzhou. The high–high agglomeration regions grew gradually and were primarily concentrated in the center, whereas the low–low agglomeration regions were scattered around the boundary. According to the Space Syntax Expand Intensity Index (SS-EII), the main direction of urban expansion was the northeast and north, while the southeast and east expanded at a slower rate. Moreover, the overall intensity of urban expansion was highest in 2018. Finally, the reasons associated with urban expansion are explored, including demographic, economic, policy, and geographical factors.