Yiming Zhu, Yuhao Huang
Historic cities face increasing pressure from rapid urbanization, highlighting the need to understand long-term urban morphological evolution for sustainable heritage conservation. This study examines the spatial evolution of Kaifeng from the Northern Song Dynasty to the Republic of China by integrating Conzenian urban morphology with Historical Geographic Information Systems (HGIS). Four representative historical stages were reconstructed to analyze changes in urban boundaries, street networks, and functional structures. The results reveal a cyclical process of expansion, contraction, and re-expansion driven by political transformation, Yellow River flooding, and shifts in transportation systems. Kaifeng’s urban structure evolved from a highly legible axial imperial layout to a multi-centered and increasingly complex configuration, accompanied by a transition from water-based to transportation-oriented functions. A coupled institution–environment–transportation mechanism is proposed to explain the city’s long-term morphological dynamics.