Studies On Multi-dimensional Immovable Property Topological Data Model And Modeling Method

The improvement of the urbanization level leads to the increasing demand of urban land,which makes land use and development in urban areas expand in the vertical direction and promotes the emergence of various complex shapes of immovable property.The three-dimensional(3D)use of land and complex shapes of immovable property make the existing two-dimensional(2D)immovable property management modes show many drawbacks.For example,it unable to manage the hierarchical utilization of land and it is difficult to define the case of inconsistencies in the vertical direction.The emergence of 3D immovable property management mode solves the problem of managing land use and complex immovable property object.The management of immovable property data involves not only spatial data,but temporal data because an immovable property object may have different state in different time,so immovable property management must consider spatiotemporal data management.Immovable property data model is the foundation of the management of immovable property data.Building immovable property data model should consider the topological relation of immovable property object,so the immovable property data model is actually a kind of topological data model.The coexistence of 2D and 3D immovable property spatial data and immovable property temporal data makes immovable property data multi-dimensional which brings great difficulty to manage immovable property topological data.The existing Geographical Information Systems(GIS)topological data model is mostly limited to the expression of the topological relation of the specific dimensional object,so it is difficult to meet the demand of organizing the multi-dimensional immovable property data which consists of both 2D and 3D spatial data and temporal data.Based on the theory of algebraic topology,this paper try to design a method to organize immovable property topology data that does not depend on dimensional objects.This method can apply to organize topological relations of all kinds of dimensional immovable property object.By using the characteristics of dimension-independent of n-G-map data structure of order topological model,the topological relations of immovable property objects are organized in a unified manner.Based on the basic operations of n-G-map object,the dimension-independent topology modeling and operation for multi-dimensional immovable property are implemented.The researches involving in this paper includes the following aspects:(1)This paper analyzes and discusses the multi-dimensional GIS data model theory,and summarizes the existing problems of the multidimensional GIS data model.On the basis of defining the basic unit of immovable property,the immovable property spatial object and time dimension are combined to generalize the types of multidimensional real estate objects and the adjacency and incidence relations between multi-dimensional real estate objects are analyzed from the point of view of topological relation organization.For the defects in existing topology relational organization methods,the dimension-independent design idea of multi-dimensional immovable property topological data model is proposed to break through the limitations of the existing multidimensional GIS data model and the multidimensional immovable property topological data concept model is designed based on the basic elements.(2)Three multidimensional object topological data models based on algebraic topology theory are compared,and their advantages and disadvantages are analyzed in terms of algebraic properties,ease of operation and dimension expansion.The ordered topology model is chosen as the basis of the multi-dimensional immovable property object topology data model.By comparing the applicability of two implementation structures of the ordered topological model in expressing and operating immovable property objects,the n-G-map data structure is chosen to organize multi-dimensional immovable property topological data.In order to implement the storage of the multi-dimensional immovable property data in the database,the object-tuple expression of n-G-map data structures is presented based on the concept of cell-tuple.This expression method can support immovable property object with holes,and the feasibility and effectiveness of the method are proved through database operation case.(3)Based on analyzing the defects of the traditional extrusion modeling approach in the aspect of constructing geometry model for immovable property object,an improved extrusion approach based on non-overlapping footprints is proposed to construct geometric model for immovable property objects.This approach constructs geometric models by removing the overlaps between footprints and spreading the extrusion intervals which can avoid ambiguity.In order to avoid redundancies in geometry objects,three criteria are proposed to judge the redundant objects which can ensure the validity of the constructed geometric models of immovable property objects.The feasibility of this approach is verified by the experiment.(4)Based on the basic data structure and operation of n-G-map,the data structure of immovable property object is defined and the multi-dimensional immovable property topological modeling approach based on n-G-map and non-overlapping footprints is proposed.Moreover,the approaches of merging and splitting the immovable property objects are designed.These approaches are not dependent on specific dimension objects,and have strong dimension universality.(5)Based on the 3D cadastral database building and management systems,the prototype systems of multi-dimensional immovable property database building and management systems are constructed.Different sizes and dimensions of multidimensional immovable property data are chosen to test the topological modeling approach and this approach is proved to be feasible.The linear relationship is presented between the time and space consumption and the sizes and dimensions of the data.The feasibility of the splitting and merging operations for multi-dimensional immovable property objects and the queries for multi-dimensional immovable property objects spatial-temporal relationships and temporal objects are also verified by experiments.