Transformation of Spatial Structure from Monocentric to Polycentric: The Case of Qazvin Province, Iran

<div> <p>The transition from monocentric to polycentric spatial structures is recognized as a key strategy for achieving balanced regional development. Focusing on a developing region, this study empirically analyses this process in Qazvin province, Iran, over a 23-year period (2001-2023). Using the Local Moran’s I (LISA) index for spatial autocorrelation analysis, the study assesses the morphological dimension of polycentricity. The findings reveal a three-stage evolution: (1) a period of consolidation and spatial refinement (2001-2007) where the central core was strengthened; (2) a qualitative transition period (2008-2013) focusing on the densification and intensification of the main centers; and (3) a period of polycentric rise (2014-2023) characterized by the emergence of new poles and geographical differentiation, forming a more networked and complex structure. The results indicate that Qazvin province has been moving towards a more distributed, differentiated, and resilient spatial system, not only quantitatively but also in qualitative and structural terms.</p> </div>