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Urban residential regions are important parts of the urban living environment,and they are closely related to urban life.In order to meet the demands of comprehensive analysis and simulation of urban environments,this paper combines the concept of virtual scene and integrated modeling in the virtual geographic environment (VGE)to design a data organization method for constructing urban residential region for modeling.Through the abstraction of system,object and relation,the complex environment information of an urban residential region can be described and organized in a hierarchical structure.In addition,the universal data description and eXchange model (UDX)was also employed to describe and store the data content for urban residential regions in a uniform manner.The data content that meets the demands of a geo-analysis model can be extracted from the modeling scene,thus supporting the integration of different geo-analysis models and the modeling scene.The experimental results show that the proposed method can effectively organize the heterogeneous urban environment data and provide the demanded modeling data conveniently for the geo-analysis models from different research areas.

It briefly reviewed the history of geographic information content development since the existence of geographic information system. It pointed out that the current definition of geographic information is always the extension from the "spatial+ attributes" basic mapping framework of geographic information. It is increasingly difficult to adapt to the analysis and application of spatial-temporal big data. From the perspective of geography research subject and content, it summarized systematically that the content and extension of the "geographic information" that geography needs. It put forward that a six-element expression model of geographic information, including spatial location, semantic description, attribute characteristics, geometric form, evolution process, and objects relationship.Under the guidance of the laws of geography, for geographical phenomenon of spatial distribution, temporal pattern and evolution process, the interaction mechanism of the integrated expression, system analysis and efficient management, it designed that a unified GIS data model which is expressed by six basic elements, a new GIS data structure driven by geographical rules and interaction, and key technologies of unstructured spatio-temporal data organization and storage. It provided that a theoretical basis and technical support for the shift from the surveying and mapping geographic information to the scientific geographic information, and it can help improving the organization, management, analysis and expression ability of the GIS of the geographical laws such as geographical pattern, evolution process, and interaction between elements.

Using GIS, data models of geology via geometric descriptions and expressions are being developed. However, the role played by these data models in terms of the description and expression of geological structure phenomenon is limited. To improve the semantic information in geological GIS data models, this study adopts an object-oriented method that describes and expresses the geometric and semantic features of the geological structure phenomenon using geological objects and designs a data model of regional geological structures by integrating geometry and semantics. Moreover, the study designs a semantic "vocabulary-explanation-graph" method for describing the geological phenomenon of structures. Based on the semantic features of regional geological structures and a linear classification method, it divides the regional geological structure phenomenon into 3 divisions, 10 groups, 33 classes and defines the element set and element class. Moreover, it builds the basic geometric network for geological elements based on the geometric and semantic relations among geological objects. Using the ArcGIS Diagrammer Geodatabase, it considers the regional geological structure of the Ning-Zhen Mountains to verify the data model, and the results indicate a high practicability.

Discrete Global Grid(DGG) provides a fundamental environment for global-scale spatial data's organization and management. DGG's encoding scheme, which blocks coordinate transformation between different coordination reference frames and reduces the complexity of spatial analysis, contributes a lot to the multi-scale expression and unified modeling of spatial data. Compared with other kinds of DGGs, Diamond Discrete Global Grid(DDGG) based on icosahedron is beneficial to the spherical spatial data's integration and expression for much better geometric properties. However, its structure seems more complicated than DDGG on octahedron due to its initial diamond's edges cannot fit meridian and parallel. New challenges are posed when it comes to the construction of hierarchical encoding system and mapping relationship with geographic coordinates. On this issue, this paper presents a DDGG's coding system based on the Hilbert curve and designs conversion methods between codes and geographical coordinates. The study results indicate that this encoding system based on the Hilbert curve can express space scale and location information implicitly with the similarity between DDG and planar grid put into practice, and balances efficiency and accuracy of conversion between codes and geographical coordinates in order to support global massive spatial data's modeling, integrated management and all kinds of spatial analysis.

Without taking polyline global structure into consideration, current polyline tessellation methods tend to make low quality decomposition. It makes them difficult to support vector mapping with large dataset and dynamic mapping with high update rate. This paper proposed a polyline momentum function and designed a monotone decomposition and tessellation method. The monotonous increasing intervals of the momentum function, as the gradient intervals of polyline, are divided continuously into optimized triangle strips. The monotone decreasing intervals of the momentum function, as the mutational intervals of polyline, are divided discretely into optimized triangle fans. The experiment results show that the decomposition quality measured by the numbers of triangulation vertices, triangles and primitives using this method are better than that based on vertex and line segment and can significantly improve the drawing efficiency for polyline. This method is also applicable to closed, width gradient and smooth line style.

Great strides have been made in Geographic Information Systems (GIS) research over the past half-century. However, this progress has created both opportunities and challenges. From a geographic perspective, certain challenges remain, including the modelling of geographic-featured environments with GIS data model, the enhancement of GISs analysis functions for comprehensive geographic analysis and achieving human-oriented geographic information presentation. Several basic theoretical and technical ideas that follow the workflow and processes of geographic information induction, geographic scenario modelling, geographic process analysis and geographic environment representation are proposed to fill the gaps between GIS and geography. We also call for designing methods for big geographic data-oriented analysis, making best use of videos and developing virtual geographic scenario-based GIS for further evolution. (VLID)3299571