| 摘要: |
| 桥下空间是超大城市中一笔可观的公
共空间资源却长期不为公共利用，本文以木樨
地桥下空间为突破口，研究总结其长久被市民占
用开展公共活动的本质原因是桥区周围有大量
居住区而公共活动配套严重不足，由此将研究
范围扩大至中心城区所有城市道路桥下空间，划
定环境研究范围并对环境型进行分类，利用分
层分析法构建评价体系计算桥下空间公共性需
求，结合自然断点法划分公共性需求类型以指
导后续桥下空间的规划再利用。 |
| 关键词: 桥下空间 环境类型 公共性需求 大
数据分析 公共空间治理 |
| DOI：10.13791/j.cnki.hsfwest.20230313 |
| 分类号: |
| 基金项目:教育部第二批新工科研究与实践项目（E-ZYJG20
200215）；高校基本科研项目（XNAUEA575000
0120）；住建部绿色城市示范项目（2019-S-011） |
|
| Research on Under-Bridge and its Public Demand Evaluation in Mega City Based on Multi-Source Data: A Case Study of Beijing |
|
WU Songtao,WANG Jingyuan,ZHAO Dawei,RONG Jinghong
|
| Abstract: |
| Informal space is a kind of space in urban that is generated according to actual needs
and whose functions are inconsistent with planning assumptions. Citizens’ occupation of the under bridge space is one of them. Different from formal spaces, informal spaces formed on demand are
often more reasonable. Under the goal of improving the ability of spatial governance to achieve high quality development, research on the causes of informal space and the exploration of reasonable
redistribution of space resources are one of the important ways of spatial governance in megacities.
The under-bridge space is a considerable public space resource in a mega city. Taking Beijing as
an example, according to statistics in 2019, the usable area of the under-bridge space reaches 402
ha, about 244 ha has been used, and about 158 ha has not been used, moreover, most of used Parts
are not available to the public. The paper first researched on the under-bridge space of Muxidi.
After investigation, it was found that the space, which was planned as a private parking, has a large
number of citizens gathering there to do activities every night during peak hours. Through the
analysis of the density of residential areas within 800 meters around the under-bridge space and the
analysis of the supporting conditions of activity places, it is concluded that the essential reason why
it has been occupied by citizens for a long time to carry out public activities is that there are a large
number of residential areas around the bridge and the supporting facilities for public activities are
seriously insufficient. Based on the consistency of research conclusions on environment of under bridge space of Muxidi and its usage phenomena, the research scope is expanded to all under bridge spaces of urban roads, a total of 119. The environmental research scope is delineated and
the environmental types are classified. The method is used to construct an evaluation system to
calculate the public demand of the under-bridge space, and combining the Jenks to divide the public
demand type to guide the follow-up under-bridge space reuse. The specific method is as follows:
firstly, the urban spatial functions are divided into four categories: residence, industry, government
affairs, and culture. Correspondingly screen POI data, delineate the research buffer zone with a 15
min living circle (800 m), and use the spatial overlay method to calculate each zone in each buffer
zone. The number of similar POI can be used to judge the dominant environmental type. The study
found that the dominant environment around the 119 bridges is mostly residential, reaching 98,
accounting for 82%. This means that it is necessary to investigate whether there is a potential gap in
supporting public activities like the Muxidi Bridge. Therefore, in the second step, the spatial data of
98 residential environments under bridges were extracted separately, and the supporting conditions
of activity place within 5 min living circle of each residential area were analyzed using the way of
spatial connection. The study found that there are indeed a large number of residential areas without
activity places like parks and squares within 300 m. Corresponding to each under-bridge space,
there are almost all residential areas lacking parks and squares, indicating that there is indeed a
huge necessary in public activities. Combined with Jenks, the under-bridge space of residential
environment can be divided into three categories: the type with extreme shortage of public activities
supporting facilities (accounting for 80%~100%), the type with relatively short supply (accounting
for 60%~80%), and the type with general shortage (accounting for 10%~60%). The third step is to build an evaluation system for the publicity demand of under-bridge space, taking the environmental type of under-bridge space as one of the factors to judge
publicity demand, and combining two more indicators as judgment factors, one is the road network density that directly affects the openness and publicity
of urban space, the other is the walkability of the road to which the under-bridge space belongs. What’s more, the judgment matrix is used to assign values
to factors, and the subtypes of the three indexes of environment type, road network density, and walkability are standardized and valued, then compared
with the weights Multiply and add up to get a comprehensive evaluation formula for the publicity requirements of each under-bridge space. The calculation
results are divided into five categories based on Jenks: publicity demand of lower, low, medium, high, and higher. In sum, three conclusions are drawn: 1)
The overall public demand of more than 40% is high, and the follow-up planning and utilization of under-bridge spaces are mainly below 2 000 m2; 2) The
existing uses of under-bridge spaces with the public demand in high and higher do not reasonable; 3) The under-bridge spaces of secondary trunk roads and
Dongcheng District have the highest public demand. This paper provides a way to use the under-bridge spaces rationally by “determining supply according
to demand” to achieve the goal of refining space governance. |
| Key words: Under-Bridge Space Environmental Form Public Demand Big Data Analysis Public Space Governance |
