Delineation of an urban agglomeration boundary based on Sina Weibo microblog 'check-in' data: A case study of the Yangtze River Delta

•Delineation of an urban agglomeration boundary is an inevitable requirement for regional planning.•This paper delineated the boundary of urban agglomeration based on people's activity.•Sina Micro-blog Check-in data was collected to support our analysis in the Yangtze River Delta Urban Agglomeration.•We found a more accurate result that activity space of the YRDUA was much smaller than current administrative space.

Statistical, morphological, and modelling methods have long been used to delineate spatial boundaries of urban agglomeration. According to the theory of space of flows in the era of globalisation and informatisation, we developed a new approach that uses activity data to analyse activity intensity, closeness, and connection to comprehensively delineate the boundaries of urban agglomeration. We also collected 1,545,449 valid check-in records of the Sina Weibo microblog over two weeks to empirically delineate the boundary of the Yangtze River Delta urban agglomeration (YRDUA) in China. According to our new method, we determined that the space of the YRDUA was much smaller than that based on the administrative division. The socioeconomic index system for the regional planning of the YRDUA (2009-2015) yielded a more accurate result.