Spatial Distribution Characteristics and Strategies of Urban Agglomerations from a Spatiotemporal Perspective: An Empirical Analysis Based on the Nanjing Urban Agglomeration

This study selects nine cities within the Nanjing urban agglomeration. Based on the traditional gravity model, the study constructs an evaluation index system for assessing the comprehensive strength of cities, applies the entropy method to calculate the cities overall strength, and uses an improved potential model to investigate the internal spatial structure and development relationships within the urban agglomeration. The results indicate that from 2010 to 2020, the southern region of the Nanjing urban agglomeration formed the strongest interaction zone. Nanjing exhibits a clear agglomeration effect, with some peripheral cities benefiting from its radiation effect, while Huaian and Wuhu, located at the northern and southern ends of the agglomeration, lag in development and show relatively slow growth. Based on these findings, the study proposes a strategy for developing the Nanjing urban agglomeration into a hierarchical urban system of one core, one sub-core, and three tiers and a spatial structure of one center, three circles, and four clusters, aiming to create an imbalanced balance in spatial distribution.