基于城市形态学原理的面状地物层次索引方法

A New Hierarchical Spatial Index for Area Entities Based on Urban Morphology

城市形态取决于城市规模、地形、城市用地功能组织和道路网结构等因素,其基础骨架是交通轴线和水系轴线。本文基于城市形态学基本原理,依据道路、水系等自然要素将城市空间划分为Enclave、Block、Superblock和Neighbour-hood4个层次,在此基础之上,提出一种新的空间数据层次索引方法,并扩展现有空间索引分类框架。该空间划分方式不仅符合人的认知,同时有效地避免地物跨网格分布的情况,从而不产生索引记录冗余,提高检索速度。

Urban morphology is closely related with natural conditions,functional organization of land use and road network structure.Its basic skeleton is formed by axes of road and hydrographic network.Based on the principle of urban morphology,urban space can be partitioned into four levels with its components being enclave,block,superblock and neighborhood,which is obtained by some topographic features such as roads and hydrographic networks.Obviously,this way of partition is very natural and consistent with human cognition,and thus the basic components at each level are called natural grids.Indeed,the partition can effectively avoid such case that topographic features cross grids,which often occurs in the partition based on regular grids.A new kind of hierarchical spatial index method is further proposed based upon the natural grids,which can be combined into existing classification of spatial index to obtain a new extended classification framework.Particularly,there is no redundancy of index records based on the new spatial index,so that it can improve the efficiency of spatial query.Several experiments are employed to prove that the redundancy of index recording in grid affects its efficiency greatly.In addition,the approaches of space partition and index building in this paper can be further used for map generalization and map updating,thus provide the basis for them in both theory and technology.