干旱区绿洲城市边缘区识别及空间演变研究——基于POI数据分析

Research on the Identification and Spatial Evolution of Fringe Area of Oasis Cities in Arid Region—Data Analysis Based on POI

以干旱区典型绿洲城市乌鲁木齐市为例,基于2009—2017年网络兴趣点数据(P O I),运用核密度方法和自然点间断法识别城市边缘区,分两个阶段从扩张数量、扩张强度、扩张方向等方面分析边缘区新增区域的内部结构及空间扩展特征,并进一步探讨城市空间扩张模式。研究结果:(1)乌鲁木齐市城市扩张呈现出不规则的环状分布,城市北部的扩张区范围要明显大于南部。(2)乌鲁木齐市城市扩张在两个阶段内差异明显,2009—2013年,乌鲁木齐市城市新增范围为160k m2,扩张强度为0.85,属中速扩张,扩张方向主要是西部和东北部;2013—2017年,乌鲁木齐市城市新增范围为20k m2,扩张强度为0.09,属缓慢扩张。(3)2009—2013年,乌鲁木齐市向外扩张、内部填充和转化核心三种区域的面积之比为6.19∶4.58∶1,扩张模式主要是向外扩张;2013—2017年,乌鲁木齐市内部填充、向外扩张和转化核心三种区域的面积之比为11.15∶2.39∶1,扩展模式主要是内部填充。

Taking Urumqi,a typical oasis city in arid region,as an example,based on the network point of interest data(POI)from 2009 to 2017,the kernel density method and natural point discontinuity method are used to identify the urban fringe area.The paper from two stages analyzes the characteristics of internal structure and spatial expansion of the new fringe area from the expansion quantity,expansion intensity,expansion direction and other aspects,and then further discusses the urban spatial expansion mode.The results are as follows:(1)The urban expansion of Urumqi presented an irregular circular distribution,and the expansion area in the north of the city was significantly larger than that in the south.(2)The urban expansion of Urumqi had obvious differences in the two stages.From 2009 to 2013,the newly added area of Urumqi city was 160km2,with the expansion intensity of 0.85,which belonged to the medium speed expansion,and the expansion direction mainly in the West and Northeast;From 2013 to 2017,the newly added area of Urumqi city was 20km2,with the expansion intensity of 0.09,which belonged to the slow expansion.(3)From 2009 to 2013,the area ratio of three regions in Urumqi including outward expansion,inner filling and core transformation was 6.19:4.58:1,and the expansion mode was mainly outward expansion;from 2013 to 2017,the area ratio of three regions in Urumqi including inner filling,outward expansion and core transformation was 11.15:2.39:1,and the expansion mode was mainly inner filling.