凸壳原理判识城区扩展类型方法的缺陷分析

Defect analysis of convex hull in identifying the types of urban spatial expansion

在国家测绘地理信息局2016年全国地级以上城市及典型城市群空间格局监测项目中,采用凸壳原理方法判断甘肃省14个城市空间扩展类型(填充、外延),并利用城区紧凑度变化监测数据对城区扩展类型判断结果进行对比验证,通过两种方法结果的差异分析发现凸壳原理判识城区扩展类型方法的缺陷,并提出改进思路。

Convex hull was used to determine the spatial expansion types （filling, extension） of 14 cities in Gansu Province in the monitoring project of the national spatial monitoring system for prefecture-level cities and typical urban agglomerations in 2016 in National Administration of Surveying, Mapping and Geoinformation of China （NASMGC）. Urban expansion type judgment results were compared and verified using the urban compactness change monitoring data. Defect of convex hull in identifying the types of urban spatial expansion was discovered by the difference analysis of the results of the two methods and the improvement ideas were proposed.