一种面向对象的4层空间数据模型

针对“空间数据是否要建立拓扑关系并在数据库中显式地存储记录”一直是G IS领域争论的问题,给出了解决方案:融合拓扑关系数据模型和面向实体数据模型,进而在分析和总结现有数据模型的基础上提出了一种面向对象的4层空间数据模型。对模型作了4个层次划分:几何对象、基本和复杂要素、分层与分区以及多尺度表达。模型具有3个特点,即多尺度描述地理空间;能描述不同要素层、不同区之间的关系;用户可根据实际情况自定义要素层拓扑关系。最后给出了模型在自主开发的地理数据库管理平台Geoinfo中的应用情况。

An Object-oriented Four-leveled Spatial Data Model

It is an controversial problem whether it is necessary to build topological relationship for spatial data and to store the relationship clearly in database.This paper puts forward a solution that the topological relationship data model and entity-oriented data model should be fused,and then an object-oriented four-leveled spatial data model is built based on original models.The four-leveled model includes two levels(geometric object,and simple and complex features) based on micro-data organization and two levels(layer and section,and multi-scale representation) based on macro-data organization.The proposed model has the following virtues: to represent the geographic space with multi-scale,to describe the relationship between the different layers and sections clearly,and to define the topological relationship types of layers by users.Finally,the model is used to our geographic database administration platform.