Current studies on activity space are limited by the conceptualization of absolute physical space that fails to consider the heterogeneity of relational spaces reconstructed from spatial interactions of human movements between locations and falls short in incorporating the inherent hierarchical property of human mobility. Consequently, these approaches cannot faithfully reflect how people interact with urban spaces through travels. From the lens of relational space, this study proposes the new Hierarchical Activity Region Model (HARM) to derive the space and hierarchical properties of activity spaces perceived by various urban groups. We demonstrate the enhanced validity of our model on travel behavior in Manhattan, New York City, before, during, and after Hurricane Sandy on the basis of taxi data. Empirical results show that intra-urban travel retains clear hierarchical organization, even under disruption of a major weather event. Yet, travel undergoes a compression effect in travel hierarchies, characterized by fewer hierarchical levels and enlarged characteristic scales, followed by a rebound. Clustering the derived hierarchies reveals pronounced heterogeneity that stems from differences in population profiles; some groups sustain deeper structures or recover quickly, while others experience a persistent loss of levels. This study provides valuable insights into the functional hierarchies of urban mobility, which could inform more sustainable, resilient and equitable urban planning. The proposed methodological framework is generic for studying human mobility in broader contexts.

翻译：当前关于活动空间的研究受限于绝对物理空间的概念化，未能考虑基于位置间人类移动的空间互动所重构的关系空间的异质性，也无法整合人类移动固有的层次属性。因此，这些方法无法真实反映人们如何通过出行与城市空间互动。从关系空间视角出发，本研究提出新的层次活动区域模型（HARM），以推导不同城市群体感知的活动空间的空间与层次属性。我们基于纽约市曼哈顿地区在桑迪飓风前、期间及之后的出租车数据，验证了该模型在出行行为方面的有效性。实证结果表明，即使在重大天气事件干扰下，城市内部出行仍保持清晰的层次组织。然而，出行在层次结构上经历了压缩效应，表现为层次级别减少、特征尺度扩大，随后出现反弹。对推导出的层次结构进行聚类分析，揭示了由人口特征差异导致的显著异质性：部分群体维持了更深层的结构或迅速恢复，而其他群体则经历了层级的持续丧失。本研究为城市流动性的功能层次提供了重要见解，可为更可持续、具韧性与公平性的城市规划提供参考。所提出的方法论框架具有通用性，适用于更广泛背景下的人类流动性研究。