城市功能区视角下基于POI数据的公共厕所空间布局合理性研究

公共厕所作为最典型的公共设施,反映出城市的文明程度和管理服务水平,是打造城市文明形象的重要窗口。当前的研究主要集中在公共厕所的可达性和覆盖范围,把公共厕所当做空间上的点无差别对待,忽略了不同功能区公共厕所空间分布所异质性的问题。如何建立全面精准的公共厕所空间评价体系,分析不同区域公共厕所的综合服务能力在当前研究中明显不足,不利于公共厕所的配置规划和基本公共服务均等化的推进。多源数据的涌现为城市公共设施的研究提供了新视角,为此本文提出一个城市功能区视角下基于POI大数据的公共厕所空间布局合理性评价方法。利用词频-逆文本频率（Term Frequency-inverse Document Frequency,TF-IDF）信息加权技术,结合兴趣点（Point of Interest, POI）频率密度识别城市功能区,融合OpenStreetMap（OSM）路网密度数据和WorldPop人口数据设立人口出行活力指数,对城市功能区内的公共厕所服务进行评价;最后计算人口和空间覆盖率以及空间不平衡指数,判别街镇间的差别与街镇内公共厕所布局的合理性。该方法以多源数据为基础,定量分析不同功能区内公共厕所配置的合理性,并探讨公共厕所空间配置的差异化因素。以国内城市化程度最高之一的上海市为例进行计算,研究发现:① 不同的城市功能区内厕所的配置数量不同,商服功能区的规划数量最多,商服功能区中公共厕所配置的合格度也最高,此外,“工业-商服”、“绿地-商服”等商服相关的联合功能区的合格度也处于较高水平,这是由于大量商业服务机构均对外提供公共厕所服务,提升了该地区的公共厕所的服务能力;② 公共功能区内的合格度最低,仅有10.27%,与该类型附属公共厕所设施的开放程度相关;③ 上海市各街镇公共厕所的合格度整体较好,平均空间覆盖率达到67.31%,平均人口覆盖率达到70.72%;街镇内公共厕所服务和出行活力分布之间的不平衡指数从0~0.76不等,其中不平衡指数小于0.4的共有147个,占比69.34%,表明这些街镇内公共厕所空间配置比较合理。公共厕所配置合理性从上海市区向西南、东南、崇明岛有明显的递减,而向西北地区则没有明显的衰减,呈现出连片的较好的服务能力。结果表明,这种方法充分考虑了公共厕所所属功能区和人口出行活力异质性的问题,空间分析上更加精准,可以为城市公共设施规划提供参考建议。

Research on the Rationality of Public Toilets Spatial Layout based on the POI Data from the Perspective of Urban Functional Area

As the most typical public facility, public toilets reflect the civilized level and management service level of the city and are an important window for building a civilized image of the city. Current research focuses on the accessibility and coverage of public toilets, treats public toilets as spatial points without discrimination, and ignores the heterogeneity of public toilets in different urban functional areas. How to establish a comprehensive and accurate public toilet space evaluation system and analyze the comprehensive service capabilities of public toilets in different regions is obviously insufficient in the current research, which is not conducive to the deployment of public toilets and the advancement of the equalization of basic public services. The emergence of multi-source data provides a new perspective for the research of urban public facilities. Therefore, this paper proposes a rationality evaluation method of public toilet spatial layout based on POI big data from the perspective of urban functional area. We use Term Frequency-inverse Document Frequency (TF-IDF) information weighting technology combined with Point of Interest (POI) frequency density to identify urban functional areas, and integrate OpenStreetMap (OSM) road network density and WorldPop population data to construct a population travel vitality index and evaluate public toilet services in urban functional areas. Finally, the population and spatial coverage rate and the spatial imbalance index are calculated to determine the difference between streets and towns and the rationality of the layout of public toilets in streets and towns. Based on multi-source data, this method quantitatively analyzes the rationality of the allocation of public toilets in different functional areas and explores the differentiating factors of the space allocation of public toilets. This article takes Shanghai, one of the most urbanized cities in China, as an example for calculation. The study finds that: ① The number of toilets in different urban functional areas is different. The number of planned commercial service functional areas is the largest, but the public toilets in the commercial service functional area have the highest qualifications. "Industry-Commercial service" and "Green Space-Commercial service" and other commercial service-related joint functional areas are also at a high level of qualification. This is because a lot of commercial service organizations provide public toilet services to the outside, which has improved the service capacity of public toilets in the area; ② The public functional area has the lowest qualification rate, only 10.27%, which is related to the openness of this type of attached public toilet facilities; ③ The eligibility of public toilets in Shanghai’s streets and towns is generally reasonable, with an average space coverage rate of 67.31% and an average population coverage rate of 70.72%. The imbalance index between public toilet service and travel vitality distribution in streets and towns ranges significantly from 0 to 0.76, of which 147 have an imbalance index less than 0.4, accounting for 69.34%, indicating the comparison of the space allocation of public toilets between these streets and towns is reasonable. The rationality of the allocation of public toilets decreases significantly from the downtown area of Shanghai to the southwest, southeast, and Chongming Island, while there is no obvious attenuation to the northwest, showing a good contiguous service capacity. The results show that this method fully takes into account the issue of the heterogeneity of the functional areas of public toilets and the travel vitality of the population, and the spatial analysis is more accurate and has more practical value.