Research On Modeling Methods Of3D Cadastral Spatial Data Model

Along with the city development and land intensive utilization degree unceasing enhancement, the utilization of land is not confined to the surface, also begins to being used in the development of air and underground. Thus,3D land ownership begins to be valued gradually. However, traditional2D Cadastre with surface rights at the core unable to express the space utilization and ownership status of this kind of land and also brings great challenges for property protection and cadastral management. With the promulgation of "property law of the People’s Republic of China, the space ownership is gradually accepted in China. Under this background, the research on3D Cadastre and space ownership management has become a hot topic.The reconstruction of3D model is the foundation of the3D analysis and data management, also the original source of3D data. Coupling the current related laws and starting from the evolution of land rights and changes in parcel concept, this paper will study the basic forms of3D Cadastre, compare and analyze the3D spatial data model and design the spatial data model conforming with3D Cadastre characteristics. Finally, this paper seeks to explore a new method to build the data model based on the discussion of3D cadastral data sources. The major results are as follows:(1)This paper collected China’s relevant laws and regulations of space right and the actual situation of the underground and ground parcel management, analyzed the source of the three-dimensional(3D) right and the way of3D right delimitation, and put forward the specific management unit of3D land rights that we call parcel volume. All methods above determine the concrete forms of3D rights volume, and choose the most suitable expression named polyhedron method for the3D rights volume.(2) Through the analysis the ownership elements of two-dimensional(2D) cadastre, based on the morphological features of parcel volume, this paper extended the ownership elements to boundary point, boundary line, boundary polygon and parcel volume under3D cadastre. It also studied2D cadastral restriction relationship between ownership elements. Then expanded this restriction relationship to three-dimension, based on which it designed3D cadastral spatial data model.(3) This paper designed the acquisition method of two types of3D cadastral data from the perspective of the existing cadastral data acquisition method. Then, it designed the modeling methods of two kinds of parcel volume, and verified the feasibility and effectiveness of these two kinds of methods through the way of prototype system. The final experiment result shows that the3D spatial cadastral data model designed in this paper has better expressed cadastral elements and defined the3D land space ownership effectively. And it has strong platform applicability. These two kinds of model building methods proposed in this paper have solved the basic problems of3D spatial cadastral data source and spatial data model construction, and it will help to build the3D spatial cadastral database and attempt the daily cadastral management work.