Study On Description Models And Algorithms Of Spatial Relations For Urban Planning Decisions

Spatial relations include those relations of topology, direction and distance and so on. Study on description models of spatial relations mainly focuses on the relations of topology and direction. The 9-intersection model for topology relation and direction-relation matrix model with good description capacity also have their own weakness. For example, the 9-intersection model which is used widely in some commercial software can't distinguish the instance of touching at the point or touching at the line for regions, or describe the neighborhood relation. The model is helpless for describing topology relation between objects and complexity region which has hollows. The widely used direction-relation matrix model is not good at describing the interior direction of the region object elaborately and can't describe direction of line object. The urban planning decisions consist of complex data. From the point of view of detailed extent, they include strategic planning decision and detailed planning decision. From the angle of special planning, the urban planning decisions are consisted of land use planning decision, roadway traffic planning decision, foundation facilities planning decision etc. From the angle of exhibition form, the decisions include decisions of text, forms, maps and pictures. The problems of especial spatial relations discussed above are widely existent in spatial data and text description of urban planning decisions. The relations between these decisions are strong and should be described and recognised. Then the management and analyse of urban planning decisions will be easy. There is not enough study on these spatial relations in China and abroad. So the description models and the algorithms of spatial relations are argued in this article.In this article, the studying evolution and application of spatial relations and their description models are analyzed. The description methods of spatial measurement relations are argued. The basic theories are introduced and the description methods with their strongpoint and shortcoming of description models are discussed. The characteristic of urban planning decisions' spatial relations is analyzed. The relations which can be described with spatial relation models are particularized. The expanding models are designed which can be used to describe the particular spatial relations. The scheme based on the 9-intersection model is provided which can distinguish the instance of touching at the point or at the line. The method which can describe the spatial relations of the complicated region object with hollows is brought forward. The expanding measure of spatial direction relations is advanced which is contacted tightly with the topology relation and the distance relation. The algorithms related with the models are carried out with ArcGIS Engine. The planning index system which is based on the planning unit is put forward. The spatial relation of the index units can be used to express the planning decisions' relation.The planning index system associates the whole planning decisions system and can solve partly different scale problem between the planning decisions. In the application part, the description models with their expanding parts used in the planning decisions' query are expounded.