What is the relationship between 3D cadastre and 2D cadastre?

Three-dimensional cadastre is developed on the basis of two-dimensional cadastre. The traditional two-dimensional cadastre is based on plane and takes area rights as the core content. Its most basic management unit is two-dimensional parcel, which is manifested in the corresponding rights, responsibilities and constraints of registered land, and its theoretical basis is to agree to maintain the consistency of vertical ownership of land. On the basis of two-dimensional cadastre, three-dimensional cadastre has more spatial concepts and richer land connotation. With the continuous development of society, the increasing population base and the increasing scarcity of land resources, the traditional two-dimensional cadastral management model can no longer meet the needs of social development. The purpose of establishing parcels under the framework of three-dimensional space is to better divide the ownership of land rights, boundaries and airspace within parcels. Modern cadastre is mainly marked with data and icons. It mainly collects land use status, quantity, quality, ownership of aboveground crops, location and land ownership, and its smallest unit is land use space with independent property rights. Its management form is mainly to register or express the ownership relationship of unit attributes, area information and spatial information with legal significance. Three-dimensional cadastre not only expresses the problem of land ownership completely, but also perfects the content of the whole information system.

Three-dimensional cadastre has the following characteristics: (1) Different from two-dimensional land ownership management, three-dimensional cadastre is based on three-dimensional space and uses three-dimensional coordinates to describe the ownership relationship of all materials in the land; (2) Matter does not necessarily need to include the ground in its three-dimensional space, and the relationship between matter and the ground can exist in various forms; (3) Three-dimensional parcels are surrounded by ownership expression interface. It is mainly manifested in the expression of information in three-dimensional space, the reflection of ownership relationship, the expression of cadastral quality and the use of spatial legends.