基于H/T断裂法与POI数据的建成区快速提取方法

A Fast Extraction Method of Built-up Area Based on H/T Breaks Method and POI Data

城市建成区是优化城市功能结构、实现土地集约利用的重要保障。为解决城市建成区边界提取方法复杂、效率和精度较低等问题,该文提出了一种基于H/T断裂法与兴趣点(POI)数据的城市建成区快速提取方法,借助POI数据构建不规则三角网(TIN),并利用H/T断裂法生成自然城市边界,去除碎多边形后即为城市建成区范围;通过与传统社会经济数据、开放数据对比,验证了城市规模存在长“尾”分布特征。以北京为例,将该文方法提取结果与Densi-Graph方法提取结果进行对比,验证了H/T断裂法在城市建成区提取中的可行性;选取北京、济南、武汉和兰州4个典型城市,进行建成区提取结果分析与Ht-index缩放层次曲线的绘制。研究表明:H/T断裂法所依赖的Zipf定律在城市研究中具有普适性;POI数据在城市边界特别是在全国地级市尺度城市边界识别中具有可行性;基于POI数据利用H/T断裂法进行城市建成区边界识别,数据可获取性强、适用范围广、可靠性高,提取过程省去了刻画核密度值和面积的关系、判定临界值等工作,简单快捷。

Urban built-up areas are an important guarantee for optimizing urban functional structure and realizing intensive use of land.In order to solve the problems of complexity,low efficiency and low precision of urban built-up area boundary extraction methods,this paper proposes a rapid urban built-up area extraction method based on H/T breaks method and point of interest(POI)data.In the method,the urban built-up areas are extracted by constructing triangulated irregular network(TIN)using POI data,generating the natural urban boundary using H/T breaks method after removing the broken polygons.Taking Beijing as an example,the extraction results of the proposed method and the Densi-Graph method were compared to verify the feasibility of the H/T breaks method in the extraction of urban built-up areas.Four typical cities including Beijing,Jinan,Wuhan and Lanzhou were selected,to analyze the results of built-up area extraction and draw the Ht-index zoom level curve.The research shows that the Zipf′s law on which the H/T breaks method relies is universal in urban research;POI data is feasible in the identification of urban boundaries,especially at the national prefecture-level city-scale urban boundaries;the proposed method is proved with strong data availability,wide application range,and high reliability;the extraction process is simple and fast by eliminating the need to describe the relationship between the nuclear density value and area,and judging of the critical value.