Source of data.

The present study investigates the dynamic evolution characteristics of urban spatial morphology by analyzing real road network data from 2000, 2010, and 2020, along with nighttime lighting data employing spatial analysis methods and spatial syntax models. Accordingly, two separate dimensions of urban morphology: internal and external, are covered. First, the integration and synergy of interior morphology features are analyzed using spatial syntactic modeling. Subsequently, the spatial compactness, fractal dimension, and level of center of gravity shift of the city are assessed by combining the nighttime lighting data with the earlier dataset. This analysis facilitated the deep exploration of the spatiotemporal evolution of the city’s external morphology. Building upon this foundation, the interaction between the "internal and external" domains was analyzed further. The main findings of the study reveal a synchronous pattern of urban expansion throughout the evolution of urban spatial morphology. Furthermore, the urban form was observed to undergo a progressive transformation, transitioning from a "single core" morphology to a "primary and secondary double core" morphology. Over time, this development progressed and evolved into a "belt-like multi-core" structure. Additionally, the coupling characteristics further validate the relationship between the structure of the road network and the urban morphology in river valley-type cities. In particular, accessibility of dense and horizontally distributed transportation network was found to significantly influence the spatial development of these cities. As observed, the findings provides valuable insights into understanding the characteristics of internal and external associations regarding urban spatial patterns.

本研究以2000年、2010年及2020年的真实道路网络数据，结合夜间灯光数据（nighttime lighting data），运用空间分析方法（spatial analysis methods）与空间句法模型（Spatial Syntax Model），探究城市空间形态的动态演化特征。据此，本研究涵盖城市形态的内部与外部两个独立维度：首先通过空间句法建模，分析内部形态特征的整合性与协同性；随后结合前述数据集与夜间灯光数据，评估城市的空间紧凑度、分形维数（fractal dimension）与重心迁移水平，以此深入探析城市外部形态的时空演化进程。在此基础上，本研究进一步分析了"内部-外部"两大领域间的相互作用。研究主要发现显示：在城市空间形态演化过程中，城市扩张呈现同步模式；城市形态经历了渐进式转型，从"单核心"形态逐步过渡至"主次双核心"形态，随时间推移进一步演化为"带状多核心"结构。此外，耦合特征（coupling characteristics）进一步验证了河谷型城市（river valley-type cities）的道路网络结构与城市形态间的关联关系。具体而言，密集且呈水平分布的交通网络可达性（accessibility）对这类城市的空间发展具有显著影响。本研究结果可为理解城市空间格局的内外关联特征提供宝贵的学术视角。