Mapping the High-density Urban Land from a 3D Perspective: The Future Land War Between Surface Space and Low-altitude Space

With the burgeoning development of the low-altitude economy, China's spatial utilization model is experiencing a profound paradigm shift. As a result, both surface and low-altitude spaces are confronted with intense competition for spatial resources. This study employs a comprehensive mixed-methods approach, integrating cartographic theory analysis, three-dimensional spatial modeling, and in-depth comparative case studies in Shenzhen. The aim is to systematically unveil the crucial issues regarding the utilization of "surface-low altitude" spatial resources from a three-dimensional vantage point:
(1) There exists an overlap in the three-dimensional spatial utilization between low-altitude flight spaces (such as those occupied by drones) and existing ground property rights (such as high-rise buildings).
(2) The two-dimensional land management system encounters ambiguous boundary problems when addressing vertical space utilization.
(3) Inconsistent terminology leads to substantial discrepancies in the interpretation of low-altitude rights among different jurisdictional departments (such as transportation, aviation, and land management departments).
The research findings yield three fundamental insights: Firstly, the conceptual transition from planar "land" to three-dimensional "space resources" necessitates a redefinition of legal and technical frameworks. Secondly, through prototype testing, expanding the LADM (the ISO-19152, Land Administration Domain Model) to establish a three-dimensional land management system is anticipated to effectively handle integrated resource management of "surface-low altitude." Thirdly, the vertical-space-stratified governance strategy has the potential to unleash supplementary space resources within high-density urban regions. The findings of our research could offer a comprehensive perspective for the future governance of urban land and low-altitude areas. This stands in contrast to current practices that treat these two resource aspects in isolation.