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区域是GIS空间分析的基本单元。它是环境科学、土壤科学等领域中广泛存在的一类地理实体。这类实体抽象概括为GIS中空间目标时不可避免地带有模糊性。利用模糊集这个强有力的数学工具,首先基于场模型提出了表达GIS中模糊区域目标的方法,分析了其空间不确定性。继而,建立了模糊区域的形态描述模式,即模糊区域边界、内部和外部,并指出了Cohn给出的定义中的不足。在此基础上,对Egenhofer提出的九元组进行了扩展,构建了适合于描述确定和模糊区域目标间拓扑空间关系的模型。
Region is one basic unit of spatial analysis in GIS applications, which is a kind of entity existing widely in many fields such as environment science, land information science and so on. In general, the kind of entity has a common character of continuously spatial distribution, so there is inevitably fuzziness in spatial data used to represent its position when it is abstracted and generalized, and enters into GIS databases. Here, fuzzy set is taken in this paper as a strong and convenient mathematical bridge to model uncertainty and fuzziness under a GIS environment. Firstly, a new method of representing fuzzy region is proposed based on field model, and its spatial uncertainty is analyzed. On the basis of above discussion, we analyze some existing methods on how to describe the point set topology of fuzzy region by referring to some shortcomings and giving a kind of new description method. Thus fuzzy region's boundary, interior and exterior are defined in detail, and their geometric meanings are given. Finally, this paper ends with the discussion on how to describe uncertain topological relations caused by spatial uncertainty of fuzzy region based on the point set topology, and develops corresponding 9_intersection models. It is shown that the point set topology model proposed in the paper is an extension of the 9_intersection model by Egenhofer (1991).