快速的城市扩张模式引发了人们对城市复兴，尤其是对老城区城市更新的关注，我国城市发展已经由高速扩张向高质量提升转变，其中城市活力是衡量城市空间结构和民生的重要工具，如何评价城市活力以及如何保持城市活力和促进城市可持续发展也引起越来越多的关注。大数据的兴起为城市活力评价研究提供了新的契机，提高了城市活力评价的维度和粒度。
现阶段城市活力评价的研究对指标的选取和方法建设都进行了众多的尝试，但是时间维度的指标关注较少。针对此不足，本文采用了北京市一周的地铁刷卡数据，同时参考既有研究成果，采集大量开源数据，如POI、建筑物、手机信令、二手房、道路、大众点评等一系列数据，建立土地利用、社会、经济、文化、时间五个维度的城市活力评价指标体系，采用TOPSIS模型对城市时空活力进行评价，分析城市时空活力的空间分布规律，通过分区分类的方法对地区进行总结归类，提出相应的城市活力提升政策建议。具体来说，本文从雅各布斯对城市活力的定义出发，综合既有研究中广泛应用的指标体系，建立了包含五个维度共计17个分指标的指标体系，选择以五环内地铁站创建的泰森多边形为研究单元，通过GIS平台的空间分析工具，采用密度法、熵值法、熵权重法、TOPSIS、聚类分析等多种方法，以分层的方式先分别对五个维度的城市活力进行评价，并在此基础上进行多目标决策评价，最后对评价结果进行分区分类，提出相应的城市活力提升的策略。
本文结论主要有以下几点：（1）五个维度中土地利用维度、经济维度均呈现中心高、边缘低，北部高、南部低的空间分布格局；社会维度总体呈现圈层分布格局；文化维度呈现出中心边缘分布；时间维度的城市活力总体呈现多中心分布模式，分布较为分散。（2）基于TOPSIS模型的城市时空活力评价呈现中心边缘分布，其中最大的核心位于朝阳区东三环附近，其他地区也分布一些小的核心区，整体上西部及南部的城市时空活力相对较低，与未考虑时间维度指标的城市活力评价比较，考虑时间后城市活力的空间分布集聚特征更加明显，尤其是在在国贸及其附近形成大面积的高活力区，而沿中轴线地区的活力则有不同程度的下降。（3）在系统聚类结果的基础上对各分区的特征进行归纳总结，将研究区分为三个分区，分别为文化繁荣、经济发达、高强度土地利用的传统城市活力区；人口密集、年轻人较多、活动持续时间长、高强度土地利用的现代城市活力区；土地利用强度低、人口少、活动少的城市活力提升潜力区。传统城市活力区主要分布在二环内及东北部扇形地区，活力提升的重点是基础设施更新，促进人员流动与交流；现代城市活力区主要分布在二环至四环之间，活力提升的重点是进行文化建设，形成多元包容的可持续发展的城市高活力区；城市活力提升潜力区主要分布在西部和南部边缘，少量地区分布在北五环附近，活力提升的重点是加强与中心城区形成功能互动。

The rapid urban expansion mode in urban renaissance, especially to the attention of the old city renewal, urban development in China has been from the high-speed expansion to quality promotion, the city vigor is one of the important tools to measure urban spatial structure and people’s livelihood, how to evaluate the urban vitality and how to keep the city vigor and promote sustainable development of the city also get more and more attention. The rise of big data provides a new opportunity for urban vitality evaluation research and improves the granularity of urban vitality evaluation.
At present, many attempts have been made on the selection of indicators and the construction of methods in the evaluation of urban vitality, but there is little attention on the indicators of time dimension. For this shortage, this paper adopted a week in Beijing subway card data, reference existing research results at the same time, a large number of open source data, such as POI, buildings, mobile phone signal, second-hand housing, roads, public review and a series of data, establishing land use, social, economic, cultural, time five dimensions of evaluation index system of urban vitality, The TOPSIS model was used to evaluate the urban spatial and temporal vitality, and the spatial distribution law of urban spatial and temporal vitality was analyzed. The corresponding policy suggestions for different types of urban dynamic areas were put forward through the method of zoning classification. To be specific, starting from Jacobs’ definition of urban vitality and integrating the index system widely used in existing studies, this paper established an index system consisting of five dimensions and 17 sub-indexes in total. The Tyson polygon created by subway stations within the Fifth Ring Road was selected as the research unit and the spatial analysis tool of GIS platform was used. Density method, entropy value method, entropy weight method, TOPSIS and other methods were used to evaluate the urban vitality of five dimensions in a hierarchical way, and on this basis, multi-objective decision-making evaluation was carried out. Finally, the evaluation results were classified into regions, and corresponding strategies for the improvement of urban vitality were put forward.
The main conclusions of this paper are as follows: (1) The spatial distribution pattern of land use dimension and economic dimension in the five dimensions is high in the center and low in the edge, high in the north and low in the south; The social dimension presents the distribution pattern of circle layer. The cultural dimension presents a central marginal distribution; The temporal dimension of urban vitality presents a polycentric distribution pattern and is relatively dispersed. (2) The urban spatio-temporal vitality evaluation based on the TOPSIS model presents a central edge distribution. The largest core is located near the East Third Ring Road in Chaoyang District. There are also some small core areas in other areas. As a whole, the temporal and spatial vitality of cities in the west and south is relatively low. Considering the comparison of urban vitality evaluation with time dimension indicators, the spatial distribution and agglomeration characteristics of urban vitality after considering time are more obvious, especially in the formation of large areas of high vitality in China World Trade Center and its vicinity, while the vitality of areas along the central axis has varying degrees decline. (3) Based on the results of systematic clustering, the characteristics of each area were summarized, and the study was divided into three areas, The traditional urban vitality areas with prosperous culture, developed economy and high intensity of land use; Modern urban vitality areas with dense population, more young people, long duration of activities and high intensity of land use; urban vitality promotion potential areas with low intensity of land use, small population and little activity. The traditional urban vitality areas are mainly distributed in the second ring road and the fan-shaped area in the northeast. The focus of the vitality promotion is to update the infrastructure and promote the flow and exchange of personnel. Modern urban vitality areas are mainly distributed between the Second Ring Road and the Fourth Ring Road. The focus of vitality promotion is to carry out cultural construction and form a multi-inclusive and sustainable urban high vitality area. The potential areas of urban vitality promotion are mainly distributed in the western and southern edges, and a small number of areas are distributed in the vicinity of the North Fifth Ring Road. The focus of the promotion of urban vitality is to strengthen the functional interaction with the central urban area.