Analyzing Gully Planform Changes in GIS Based on Multi-level Topological Relations

Topological relations can be used to describe qualitative geometric position relations between spatial objects in geospatial world, which plays important roles in spatial query, spatial analysis and spatial reasoning. People can apply topological relations to describe the morphological changes of real objects, such as changes of cadastral parcels, rivers, water systems, etc. Gully planform changes (GPCs) reflect the state of surface soil erosion, so it is important and valuable to describe GPCs in detail. In this paper, based on a hierarchical topological relation description method and combined with the features of GPCs in GIS, we propose a simple hierarchical topological relationship description method to describe GPCs. This method can be used to completely describe GPCs, and is more concise and efficient than the former hierarchical topological relation description method in describing GPCs.