Spatial buffer analysis is one of the important and basic spatial operation functions of geographic information system.
Studying 2D spatial buffer generation and analysis was more than the 3D spatial presently, thereby a novel 3D buffer
generation algorithm based on vector was presented in this paper. 3D spatial solid is represented by B-Rep model and it's
buffer is categorized into solid boundary buffer and solid interior, then construct the whole buffer by union operation on
them. The boundary features of 3D spatial solid are classified into point feature, line features and face features. Usually,
the statistical analysis is necessary after solid buffer generation. Thus, we proposed a new method which can quick judge
whether the buffer affecting the surrounding objects based on collision detection theory. Finally, taking the surface and
underground 3D space around University City region of Xianlin as the research area, a 3D buffer with complex
geological environment and man-made buildings is created based on the new presented algorithm, and spatial statistical
analysis is achieved based on the generated 3D buffer. The results show that the improved algorithm is efficient and
practicable, especially the proposed 3D buffer generation algorithm based on vector is applicable for convex body and
concave body comparing with current approaches.
The geographical information system (GIS) has provided the effective tools to capture, store, manage, analyze and
express the spatial information. Gradually, the research region has included the dynamical mechanism and the spatialtime
characteristics of the geography process, transmission mechanisms, uncertainty (multi-solutions), predictability,
and so on. Corresponding, GIS modeling is one of hotspots of current GIS research. The paper is the embodiment of
GIS modeling methods applied to geo-simulation research. Also it provides the model support for the management of
the ground water resources. In this paper, the methods for constructing the ground-water conceptual model through 3D
stratum model are discussed. Firstly, the constructing method of delaunay triangulation with constraint conditions is
proposed, which is suitable to the ground-water flow simulation. Then stratum (or aquifer) multi-DEMs are completed.
Based on the multi-DEMs, the Su-Xi-Chan hydrogeological conceptual model is reconstructed by irregular Tri-prism. In
order to prevent dispersed irregular tri-prism voxels from disunity, the spatial index mechanism is established for
groundwater model. Finally, the 3D groundwater simulation model is integrated with GIS, which can provide data for
3D numerical simulation. The results indicate that the integration of 3D GIS and geo-analysis model be convenient and
can accelerate process simulation of geo-science.