Topological Relationship Identification in 3D Cadastre

With the accelerated urbanization process, the trend of three-dimensional land use makes the traditional model of 2D cadastral management encounter challenges, because of insufficiency to express in 3D. Therefore, the 3D cadastre and related concepts have been proposed. The breadth and depth of its research are gradually broadened and refined. Within all the studies, the core concept of the "cadastre" is not changed, the core purpose of which is to "guarantee the legitimate geo-space for the owner of property units", and to ensure that each property unit, whether it is two-dimensional or three-dimensional, is unique, non-overlapping. We can understand the “legitimacy” characteristics from two aspects: 1) The reliability for each property unit itself, that satisfies the definition of property unit, i.e., the property unit should be connected, closed and homogenous; 2) From the space view, a property unit is unique and occupies its space exclusively, and there is no overlap among them.