国土资源调查数据地图综合狭长图斑的中剖分处理

Collapse and Partitioning of Long and Narrow Parcels in Map Generalization for National Land Survey

国土资源调查获得的土地利用图在服务不同层次、不同级别国土规划管理应用中,面临着多级数据库建设与地图综合缩编的任务需求。土地利用图中狭长图斑的中轴化是其中不可缺少的关键操作之一。针对土地利用数据全覆盖、无重叠、无缝隙及语义上多层次的特点,本文提出一种密集覆盖多边形数据的中轴化处理与拓扑关系维护的方法,用“剖分”与“归并”的思想模拟邻域多边形的扩张过程。本文算法实现建立在Delaunay三角网数据结构上,兼顾了语义相似关系的影响,经第三次国土资源调查成果的检验,本文所述中轴化及拓扑维护方法能够满足土地利用图综合实际生产的需要。

Land use maps obtained from the national land survey face the need to build multi-level databases and generalize the map in order to provide service to land planning and management applications at different levels.The collapse of long and narrow parcels in the land use map is one of the key and indispensable operations.Since the land use data has the characteristics of covering the whole area with neither gap nor overlapping area and contains multi-level semantic information,this paper proposed a method of collapse and topology maintenance for densely covered polygon data which uses the idea of"partitioning"and"merge"to simulates the expansion process of the neighborhood polygon.The algorithm in this paper is based on the Delaunay triangulation data structure,taking into account the impact of semantic similarity.Tested by the results of the third national land survey,the collapse and topology maintenance methods described in this paper could meet the requirements of land use map generalization in actual production.