Research of Models of Topological Relations of Spatial Features

Abstract

In map production it is necessary to keep the spatial relationships between map features. Generalization is simplification performed on geographical data when decreasing its representation scale. It is a common practice to simplify each type of spatial features independently (administrative boundaries first, then road network, hydrographic network, etc.). During the process, some spatial conflicts, which require manual correction, arise inevitably. The generalization automation still remains an open issue for data producers and users. Many researchers are working to achieve a higher level of automation. In order to detect the spatial conflicts, a refined description of spatial relationships is needed. This paper analyzes models of describing topological relationships of spatial features: the 9-intersections model, the topological chain model, and the E-WID model. Each considered model allows one to take into account some relations between features, but it does not make it possible to transfer them exactly. As a result, the task of developing a model of relations preserving topology is relevant. We have proposed an improved model of nine intersections, which takes into account the topological conflict that occurs when a point feature is located next to a simplified line. Line simplification is one of the most requested actions in map production and generalization. When the mesh covered the map inside the cell, there can be points, line segments, and polygon topological features, which, if the cell is rather small, are polyline features. Thus, the issue of simplification of topological features within a cell is reduced to the issue of simplifying linear features (polylines). The developed algorithm is planned to be used to solve the problem of consistent generalization of spatial data. The ideas outlined in this article will form the basis of a new index of spatial data that preserves their topological relationships.