Acta Geographica Sinica ›› 2015, Vol. 70 ›› Issue (4): 528-538.doi: 10.11821/dlxb201504002

• Orginal Article • Previous Articles     Next Articles

Dividing economic space into urban agglomerations usingthe marginal K function:A case study of the Yangtze River Delta region

Ying GE1(), MIRON John2, Yingxia PU3, Huihui ZHAO1, Yunting LI1   

  1. 1. School of Earth Science and Engineering, Hohai University, Nanjing 210097, China
    2. Department of Human Geography, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada
    3. School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China
  • Received:2014-08-25 Revised:2015-01-29 Online:2015-04-20 Published:2015-04-20
  • Supported by:
    National Natural Science Foundation of China, No.41071347


In this study, an economic space-dividing method for urban agglomerations is presented to theoretically explore the quantitative measurement of urban agglomeration clustering effects with two parameters (agglomeration degree and marginal agglomeration). A marginal analysis of microeconomics based on Ripley's K function of spatial point pattern analysis is also conducted. The study is novel in the aspect that economic space is divided via urban agglomeration degree and marginal agglomeration multi-scale estimation, and an optimal urban pattern is identified when marginal urban agglomeration reaches its maximum value. Finally, urban agglomeration economic spaces are determined accordingly. The Yangtze River Delta is taken as a case study to validate the proposed method. The results show that: (1) urban agglomeration degree estimates indicate that the urban spatial pattern of the Yangtze River Delta region in 2010 was random, but that of the region has shown a rapid increasing trend with the increase of scales of observation; (2) estimates of marginal agglomeration indicate that clustering effects of urban location and urban size reach peak values when city location and city size agglomeration scales reach 185 km to 173 km, respectively. At this point, the urban spatial pattern of the region achieves an optimized state; (3) results of spatial clustering analysis show that in the optimal spatial urban pattern, the Yangtze River Delta region exhibits a "core-periphery" spatial economic structure, in which highly clustered sub-agglomerations located in the Shanghai economic radiation circle form regional centers of economic development, while poorly clustered sub-agglomerations located along inter-regional administrative borders remain underdeveloped peripheral areas. This suggests that a negative marginal effect still hampers the migration of individuals across such areas.

Key words: economic space division, Ripley's K function, marginal analysis, urban agglomeration, Yangtze River Delta