基于人类时空活动的城市土地利用分类研究

准实时监测城市发展、掌握城市土地利用类型是日趋科学化、合理化进行城市规划的基本要求。随着信息通信技术、移动互联网技术、位置服务等的发展,海量的手机数据、浮动车数据、公交卡数据、社交网络数据等在内的人类时空活动信息为从“人”的角度动态实时感知城市土地利用、空间结构提供了可能。本文以深圳市为例,基于百万名QQ用户2013年的电子足迹数据,提出了不同类型的人类时空活动指数,以建立人类活动与城市地物间的对应关系;借鉴遥感影像不同波段记录各类地物在特定波谱区间辐射值的思想,生成各类人类时空活动指数波段图;并利用最大似然法对该“类高光谱影像”进行城市土地监督分类,获取城市的土地利用图。通过与深圳市规划图的对比验证,全体分类精度为72%。相较于传统基于“物”的遥感探测手段,基于“人”的城市感知更能反映城市内部相同地类的发展差异性。

Land Use Classification Based on Massive Human-Activity Spatio-temporal Data

Macroscopically monitoring the status of urbanization and fast acquiring the land covers or land use in urban areas is essential for urban planning, management and scientific policy-making. The rapidly developing remote sensing technologies have been recognized as an essential approach to carry out this work because of their vital ability to capture the physical features of different land use, such as the spectral and textural properties. However, these technologies could not reveal the heterogeneity of urban development and differentiate the vitality in and among cities with the similar physical properties interpreted from remote sensing images. Human-activity based sensing technologies nowadays have been recognized as a promising alternative to resolve these problems. Spatio-temporal distribution of human activities could be derived from mobile phone records and smart card records stored in the public transportation systems, social media or social networking services (SNSs), and etc. They are good indicators for the social function of land use and urban vitality. We proposed types of indices to bridge the relationships between the intensities of human activities and land covers. Similar to the spectral bands of remote sensing images, more than thirty social bands were generated in this paper to describe the social characteristics of ground objects by aggregating and gridding human activities into pixels. According to the spectral profiles of eight land covers, a supervised classification approach was then applied to infer the land covers of the research area. Validation experiments were conducted in Shenzhen, China using a large-scale of people’s historical login information on Tencent QQ, which is the most popular SNS, during 2013. Results showed that the land cover of Shenzhen could be determined with a detection rate of 72% according to an urban planning map of Shenzhen. Compared to the classification results from remote sensing images, the human-activity based sensing technologies can obtain more detailed insight into the urban form, city skeleton, and the heterogeneity of development and vitality in different urban areas.