基于POI与不透水表面指数的城市建成区提取

准确识别城市建成区边界，对科学实施城市规划和建设、促进城乡可持续发展具有重要意义。从城市建成区概念出发，综合考虑建成区连片和公共设施配置，提出一种基于POI核密度与不透水表面指数的建成区边界提取方法。该方法以不透水表面指数和市政公用设施和公共设施POI核密度为主要数据源，通过构建城市建成区综合指数（POI&ISA指数）和最佳阈值选取等步骤可实现较为准确的城市建成区提取。以武汉都市发展区为例，将该方法与基于POI方法的建成区提取结果进行对比，结果表明基于POI&ISA指数的方法提取精度较高。该方法可弥补单一POI数据源在城市尺度建成区提取中的不足，且通过对POI数据类型初选和带宽的适当选取提高对公共设施配置的表征能力，在局部地区可获得更好的建成区提取效果。

Extracting Urban Built-up Area Based on Impervious Surface Area and POI Data

Accurate identification of urban built-up area boundary is of great significance to implement urban planning and construction scientifically and promote sustainable development of urban and rural areas. From the definition, urban built-up area is the surface space with dense construction land and complete municipal public facilities and public facilities. However, existing urban built-up area extraction methods only consider one feature of built-up areas. Based on the concept of urban built-up area, this article takes the contiguity of construction land and the configuration of public service facilities into account, proposing a method of urban built-up area extraction based on POI kernel density and impervious surface area index. In this method, impervious surface area index and POI kernel density of municipal utilities and public facilities are used as main data sources, and urban built-up area can be extracted accurately by constructing POI&ISA index and selecting optimal threshold. Taking Wuhan urban development area as an example, compared with the results of built-up area extraction based on POI method, it is proved that the method based on POI&ISA index has higher extraction accuracy. This method can make up for the deficiency of single POI data source in urban built-up area extraction, improve the representation ability of public facilities through POI data primary selection and appropriate selection of bandwidth, and obtain better extraction effect of urban built-up area in local area. Moreover, the data required by this method has the characteristics of fast updating, which can fully guarantee the timeliness of extraction of built-up areas. In the future, the application and improvement research of POI&ISA index should be further carried out to enrich the theory and method of urban built-up area extraction.